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eHam Forums => Software Defined Radio => Topic started by: KK6GNP on August 15, 2013, 02:03:20 PM



Title: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 15, 2013, 02:03:20 PM
Hello, everyone.

Disclaimer:  I can sometimes come off as a know-it-all, but that is because I spend most of my free time learning. Apologies in advance if I rub anyone the wrong way with this post.  All I intend to do here is share some thoughts I've had where SDR is concerned.  You are welcome to disagree with me, but I'm not looking for an argument.  In fact, I'm always looking for insight from intelligent people, and I'm not afraid to be wrong, if I am proven so with facts.

I'm brand new to the forum, and to radio (still studying for my ticket), but I have a great interest in SDR.  I've been an IT professional for a couple decades now, and run my own consulting biz, so I'm neck deep in all kinds of computer technology.  Finding out about SDR after I already decided to get my license was a great surprise for me.

The reason for this post is because I wanted to share a couple of thoughts I've had since learning a little about SDR.  I know a lot of people around here have decided they hate SDR for one reason or another, and that's fine, but I certainly am not one of them.  As someone who works with many different types of computer technologies, I understand the potential power and flexibility that comes with being able to design custom interfaces, and flexible software (firmware) design for different devices.

The first thing I want to say is that rumors of the demise of PCs and laptops have been greatly exaggerated. Even in tech circles you will hear phrases being thrown around such as "the post PC era", but that doesn't mean exactly what is sounds like.  It is true that fewer non-business & home consumers are purchasing full-sized computers these days, deciding to use ultrabooks, tablets and phones in their place.  However, tablets and other mobile devices are designed primarily for content consumption, not content creation.  When real work needs to be done, a tablet or phone does not do the job. In my mind, amateur radio is content creation in addition to consumption.

In my consulting business, I often have clients ask me if they can get away with just using a tablet at home or when on the road, for business, and the answer is absolutely NO for most of them.  Anyone who has even tried to do something as trivial as write a long email on a tablet knows how bad they are for basic content creation uses, and the first thing people want to do is plug a keyboard in to it.  At that point, right there, your tablet becomes a laptop, more or less.  An under-powered, under-featured, though very portable laptop that is locked into a non-business operating system (iOS, Android, etc).  I could go on and on about the shortcomings of mobile devices for work and content creation, but you get the point, and probably already did before I posted, if you own a tablet already.

One of my computer hobbies includes playing with video and music production.  When I first started reading arguments about the superiority of knobs and buttons on standard radios, vs mouse and keyboard for SDR's, the first thing that came to mind is that this is another place where usb controllers can be used.  I've seen that there are some usb VFO knobs out there already, but those could be expanded to do pretty much anything a standard radio does as far as physical controls, and they can be used with any SDR the builders want to support.  I personally own a medium sized synthesizer keyboard controller that has zero capability of generating any output of its own, other than controlling software on my computer.  Some of these usb controllers for music and audio/video production are quite elaborate, and are not very expensive at all compared to their full-featured hardware counterparts.  Take this USB digital DJ software controller example:

http://www.digitaldjtips.com/wp-content/uploads/2010/08/NI-TRAKTOR-KONTROL-S4_controller-3.png

I know I'm not the first person to think about this, but some of the arguments against SDRs here seem to suggest that "the PC is dead" and/or that standard radio controls are better.  The PC is not dead, and won't be dead until computers have completely automated humans out of work.  They may change and evolve, but we humans still have the same body parts we've always had, and for now, we are still doing most of humanity's work.  We need larger screens, especially as we age, and we still need the precision control of a pointing devices for those screens.  One thing you can look forward to is much more voice and gesture control of computers coming soon.  VR interfaces may be coming much sooner than anyone thought as well, with devices like the Oculus Rift coming.

I don't disagree with the argument against keyboard and mouse only control for radios.  Those tools are not ideal for many things.  However, this is a problem that is easily addressed, and I think the VFO controllers are just a small sample of what may come in the future.  This might be another neat area for homebrewers to tinker as well.

I look forward to your comments.  I won't engage in any fights about how good or bad current SDRs are, because I believe they are here to stay, and it's hard for me to imagine most new radios not being SDR-based in the future.  I could be completely wrong, but technology is changing much more rapidly these days, and the changes will continue to ramp up exponentially over the next decade and beyond.  Every new generation of tech is speeding the rate at which we create the next jumps in tech, and I am seeing this across all sectors I follow.

Which traditional transceiver manufacturers today are selling or are currently designing SDR-based or full SDR radio equipment already?


Title: RE: SDR Knobs and Buttons in the future
Post by: K9IUQ on August 15, 2013, 02:47:35 PM
I'm always looking for insight from intelligent people, and I'm not afraid to be wrong, if I am proven so with facts.

I'm brand new to the forum, and to radio (still studying for my ticket),

Ok I will give some intelligent insight.  :) First get a Ham License and learn about operating a Radio with Knobs. It is a completely different experience operating a SDR radio with a  mouse or keyboard with computer, and for the most part it is not pleasant. You will see that a good ham needs to run more programs than the one running the SDR. He needs the DX Cluster, Digital program, Propagation program, Dx Atlas, Ham Cap, Ionoprobe, read emails, surf while listening to Ham Radio, look up calls on QRZ.com, etc all running at the same time. Window (Program) "Focus" becomes a real problem. One needs multiple monitors or multiple computers..

So get the Ham license, and learn what Ham Operating is all about before jumping into SDR's right off the bat.

FWIW I am NOT against PC's I worked with/on them every day before I retired. I have had computers in my Shack since 1978 when I bought a TRS-80. My first Ham program was a RTTY program. I love computers and what they can do for me in my ham life. I just do not want a knobless SDR that requires a computer. As everyone here in this forum knows - been there & done that.

Stan K9IUQ


Title: RE: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 15, 2013, 03:20:04 PM
I'm always looking for insight from intelligent people, and I'm not afraid to be wrong, if I am proven so with facts.

I'm brand new to the forum, and to radio (still studying for my ticket),

Ok I will give some intelligent insight.  :) First get a Ham License and learn about operating a Radio with Knobs. It is a completely different experience operating a SDR radio with a  mouse or keyboard with computer, and for the most part it is not pleasant. You will see that a good ham needs to run more programs than the one running the SDR. He needs the DX Cluster, Digital program, Propagation program, Dx Atlas, Ham Cap, Ionoprobe, read emails, surf while listening to Ham Radio, look up calls on QRZ.com, etc all running at the same time. Window (Program) "Focus" becomes a real problem. One needs multiple monitors or multiple computers..

So get the Ham license, and learn what Ham Operating is all about before jumping into SDR's right off the bat.

FWIW I am NOT against PC's I worked with/on them every day before I retired. I have had computers in my Shack since 1978 when I bought a TRS-80. My first Ham program was a RTTY program. I love computers and what they can do for me in my ham life. I just do not want a knobless SDR that requires a computer. As everyone here in this forum knows - been there & done that.

Stan K9IUQ

Thanks for the reply.  I  appreciate the advice.

I should pass my test within the next couple weeks.  Already studying General and my Extra books are on the way. ;)

Considering the investment people make in expensive radio equipment, putting two or even three monitors on a computer is relatively cheap. Decent 23" monitors can be bought for $150 each, and a video card to drive them is around $100.  I already run three 23" screens myself, so screen real estate isn't a problem.  I understand what you are saying, but as far as I am concerned, the large display capability is a huge bonus to going SDR. I was just thinking earlier that it would be cool to have one of the open source SDR developers add Chromecast support so I could stream the SDR interface to my 52" Samsung TV across wifi like I do other things.

Side Note:  Anyone who is working with multiple programs should have more than one monitor on their desk, if they can.  It makes life much easier, and has been proven in business to generally improve productivity for exactly the reason you noted ~ multiple windows/programs in focus.  Most programmers and content creators would rather jump off a bridge than work with a single monitor these days.  I refuse to write code without at least two because of the wasted time.

The main point of my post was to say that where the mouse and keyboard lacks in control for amateur radio, usb controllers can not only replace traditional radio front-ends, but allow additional manual functionality if desired, or even multiple controllers.  There are countless places in computer work where the mouse and keyboard have been supplemented or completely replaced by more appropriate controllers, and this is another perfect one for it.

On my first radio:  It's looking like my first one will be a KX3, considering my current needs and budget.  I'm sure I'll try a full size radio sooner or later, but I need something much more portable that I can also use as a base, and has some SDR capability.


Title: RE: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 15, 2013, 03:30:22 PM
Hi,

Consider the WoodBoxRadio Tmate2 USB controller:

http://www.woodboxradio.com/tmate2.html

It already works with the Flex xcvrs and the Perseus rcvr.

Barry
WB2ZXJ

Brilliant!  Thanks for sharing.  These types of controllers can be expanded as much as anyone ever needs, and because it's basically a modular front end for a great radio, you can always buy a better front end down the road as they become available, or as I said earlier, use more than one controller if required.


Title: RE: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 15, 2013, 03:42:31 PM
I think about techy things like this all the time.  Earlier I was imagining a virtual reality interface, using the Oculus Rift, where the waveforms are placed in a 3D space, and you can manipulate them by gesture and voice.  Why?  Why not?  ;)   Just call it homebrew.


Title: RE: SDR Knobs and Buttons in the future
Post by: PJ2BVU on August 15, 2013, 05:09:31 PM
The version of PowerSDR modified by the OpenHPSDR developers which is used on the ANAN transceivers from Apache Labs supports the Hercules DJ Control MP3 LE:
http://www.amazon.com/Hercules-DJ-Control-MP3-Controller/dp/B008YDU1DG

Jean-Claude PJ2BVU


Title: RE: SDR Knobs and Buttons in the future
Post by: PJ2BVU on August 15, 2013, 07:19:06 PM
That is an excellent controller. But I think that the original poster may have been asking about SDR radio
controllers -- there are many excellent audio/music controllers on the market.

More dedicated SDR hardware would be welcomed.
...
p.s.  Simon Brown's SDR-Console supports the Tmate2.  Fun times ahead.
It may not be a controller designed for SDR but PowerSDR-mRX fully supports it and you can set it up to control about anything on the rigs supported by PowerSDR-mRX:
2 jog wheels for VFO-A and VFO-B.
Knobs for RIT, XIT, filter adjustment, AF Gain ....
Buttons to select bands, turn on/off RIT/XIT, split, A->B, B->A, A=B, ...
Sliders for zoom, upper/lower frequency of filters, PAN, ...

A lot more knobs/sliders and buttons than Tmate-2, $86.00 vs 260 Euros.
Sure it is just cheap plastic compared to the Tmate-2 which is built like a brick, has a very nice display with a lot of information on it and is ergonomically slanted.
Simon has also plans to support it in the near future in his SDR-Console.

Jean-Claude PJ2BVU


Title: RE: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 15, 2013, 10:55:42 PM
Hi Jean-Claude

Thank you for your excellent post.  I have learned a lot.

BTW, do you know the name of the original poster?  I know that he is getting his call sign --
but it seems so cold -- not to have a real name to respond to.

73
Barry
WB2ZXJ


Barry,  my name is Cory.  I added it to my sig. Thanks for the comments.


Title: RE: SDR Knobs and Buttons in the future
Post by: ZENKI on August 16, 2013, 04:09:11 AM
The  way I see it its just about profit margin and getting products to the market as quickly as possible for the PC operated SDR market.

The lack of a knobbed SDR radio is more economics and a poor understanding of the potential about whats already on the market in terms of embedded processors and
real time operating systems and operating system like Linux that could easily  be embedded in a front panel that can drive a SDR. Who is kidding who, the SDR companies are really treating  hams with contempt with the crappy SDR software other associated software.

There is something like the Raspberry Pi and CubieBoard that could easily run a front  for interfacing  to a SDR complete with TFT screen, remote networking and every other feature imaginable. All we seem to get is crippled hardware that seems to fit  in era that was 2 decades ago. Most ham  SDR software reminds me of control software that I was using in the 80 and 90's via RS232 control its so primitive in its user interface. An embedded TFT screen can be programmed by a school kid so you have to wonder who ham radio companies seem to be on their own planet with such primitive  hardware and PC control systems.

Even a simple concept like linking a tablet via USB for the front panel would be a better solution than using a PC. I can control a few of my test instruments via Android and bluetooth and its a fantastic way to go.  You can have audio, a nice screen, remote operation and pretend knobs that are far better than mousing and clicking in front a PC. I am not anti PC. I had a PC before the concept of the PC existed and have used every  computer and operating system on the planet. Its just the nature of ham radio and the way we do hamming that requires a physical interface with knobs. The heart of the radio is a VFO knob and to think that there is no acceptable way on all the current SDR radios of tuning up and down the bands without  getting wrist pain and strained eyes.  The tactile feeling from mouse and keyboard tuning  just leaves me cold and  not having a VFO knob and band select buttons is a disaster. Yes I have 4 SDR receivers and they excel if you monitoring SW channels or BCB DXing Etc. But hams are like athletes when it comes to the manipulating and tuning of a radio, its a physical activity that should be made as simple as possible. No SDR software package is as effective as  a front panel  radio with knobs. Even a ergonomic terrible radio like the K3 is way ahead in terms of ergonomics and practicality  than all ham SDR software.

Some ham manufacturers will get it when its too late. The smart ones will be working on a SDR radio with knobs and a front panel. The ADAT radio is  good example. The first ham manufacturer who develops a full  DDC/DUC transceiver with a front panel that has TFT screen and knobs will hold a major advantage in the marketing warfare. I  could be wrong,  but I am confident that I am right. I use the example of test equipment manufacturers where this same battle was fought. The winner was the front panel with knobs and the software as an ancillary for printing and storing or recalling complex things like  pass fails masks or relevant EMC standards. National Instruments lauched their PC driven platform but it has really failed to capture the imagination of engineers despite  its performance. Every engineer dreams of a test bench  full of Agilent or R&S equipment with nice knobs and TFT screens. A good example is a spectrum analyzer. The worst scenario would be operating a spectrum analyzer through PC driven software. It would be so slow and cumbersome. With knobs and menus  you can make these daily routine measurements so much fast.

Another example is the professional audio engineering. Although their many products on the market that can be driven and controlled by a PC, most audio engineers still prefer a rack of boxes with knobs and buttons. They seem to have intimate connections with knobs and buttons that gives them a sense of control that is not evident on PC controlled studio gear.  The thing that has changed from the all knob audio studio boxes is the embedding of LCD/TFT or some other display technology. This is exactly  what should happen with ham radios. Knobs and embedded screens for feedback and information. The Yaesu FT5000 is an example of heading in this direction, and likewise the  TS990S. The Flex6000 radios despite  its promise will be a minor player and will be probably be discontinued in 2 years time because it wont get into the mainstream just like all prior flexradio models. Flexradio should give up and now and pursue making a radio like the ADAT radio. A  Flex6000 radio with a front panel that can be internet remoted with 200 watts of output will put Flexradio ahead of the pack. Its just unfortunate that they have chosen a path that most hams dont want

Then we come to the aircraft industry. Look inside the modern jet cockpit.  Nice screens and knobs. You dont find a PC loaded with software and a mouse! The only concession is the wide use of tablets now in the cockpit. You wont find a PC controlling a HF radio or VHF radio anytime soon on a jet. Its just a ridiculous and inefficient way of doing things, just as it is using a PC with crap software to control a ham radio.  Knobs and front panels on a DDC/DUC platform will be the way forward and the ham manufacturing companies who follow this path will be   the winners.

Anyway its hard reading the tea leafs and telling the future. However based on my experience in engineering and test and measurement whose requirements are for easy to use boxes that are ergonomic much like the ham radio market I am confident in my views.


Hello, everyone.

Disclaimer:  I can sometimes come off as a know-it-all, but that is because I spend most of my free time learning. Apologies in advance if I rub anyone the wrong way with this post.  All I intend to do here is share some thoughts I've had where SDR is concerned.  You are welcome to disagree with me, but I'm not looking for an argument.  In fact, I'm always looking for insight from intelligent people, and I'm not afraid to be wrong, if I am proven so with facts.

I'm brand new to the forum, and to radio (still studying for my ticket), but I have a great interest in SDR.  I've been an IT professional for a couple decades now, and run my own consulting biz, so I'm neck deep in all kinds of computer technology.  Finding out about SDR after I already decided to get my license was a great surprise for me.

The reason for this post is because I wanted to share a couple of thoughts I've had since learning a little about SDR.  I know a lot of people around here have decided they hate SDR for one reason or another, and that's fine, but I certainly am not one of them.  As someone who works with many different types of computer technologies, I understand the potential power and flexibility that comes with being able to design custom interfaces, and flexible software (firmware) design for different devices.

The first thing I want to say is that rumors of the demise of PCs and laptops have been greatly exaggerated. Even in tech circles you will hear phrases being thrown around such as "the post PC era", but that doesn't mean exactly what is sounds like.  It is true that fewer non-business & home consumers are purchasing full-sized computers these days, deciding to use ultrabooks, tablets and phones in their place.  However, tablets and other mobile devices are designed primarily for content consumption, not content creation.  When real work needs to be done, a tablet or phone does not do the job. In my mind, amateur radio is content creation in addition to consumption.

In my consulting business, I often have clients ask me if they can get away with just using a tablet at home or when on the road, for business, and the answer is absolutely NO for most of them.  Anyone who has even tried to do something as trivial as write a long email on a tablet knows how bad they are for basic content creation uses, and the first thing people want to do is plug a keyboard in to it.  At that point, right there, your tablet becomes a laptop, more or less.  An under-powered, under-featured, though very portable laptop that is locked into a non-business operating system (iOS, Android, etc).  I could go on and on about the shortcomings of mobile devices for work and content creation, but you get the point, and probably already did before I posted, if you own a tablet already.

One of my computer hobbies includes playing with video and music production.  When I first started reading arguments about the superiority of knobs and buttons on standard radios, vs mouse and keyboard for SDR's, the first thing that came to mind is that this is another place where usb controllers can be used.  I've seen that there are some usb VFO knobs out there already, but those could be expanded to do pretty much anything a standard radio does as far as physical controls, and they can be used with any SDR the builders want to support.  I personally own a medium sized synthesizer keyboard controller that has zero capability of generating any output of its own, other than controlling software on my computer.  Some of these usb controllers for music and audio/video production are quite elaborate, and are not very expensive at all compared to their full-featured hardware counterparts.  Take this USB digital DJ software controller example:

http://www.digitaldjtips.com/wp-content/uploads/2010/08/NI-TRAKTOR-KONTROL-S4_controller-3.png

I know I'm not the first person to think about this, but some of the arguments against SDRs here seem to suggest that "the PC is dead" and/or that standard radio controls are better.  The PC is not dead, and won't be dead until computers have completely automated humans out of work.  They may change and evolve, but we humans still have the same body parts we've always had, and for now, we are still doing most of humanity's work.  We need larger screens, especially as we age, and we still need the precision control of a pointing devices for those screens.  One thing you can look forward to is much more voice and gesture control of computers coming soon.  VR interfaces may be coming much sooner than anyone thought as well, with devices like the Oculus Rift coming.

I don't disagree with the argument against keyboard and mouse only control for radios.  Those tools are not ideal for many things.  However, this is a problem that is easily addressed, and I think the VFO controllers are just a small sample of what may come in the future.  This might be another neat area for homebrewers to tinker as well.

I look forward to your comments.  I won't engage in any fights about how good or bad current SDRs are, because I believe they are here to stay, and it's hard for me to imagine most new radios not being SDR-based in the future.  I could be completely wrong, but technology is changing much more rapidly these days, and the changes will continue to ramp up exponentially over the next decade and beyond.  Every new generation of tech is speeding the rate at which we create the next jumps in tech, and I am seeing this across all sectors I follow.

Which traditional transceiver manufacturers today are selling or are currently designing SDR-based or full SDR radio equipment already?


Title: RE: SDR Knobs and Buttons in the future
Post by: AA4PB on August 16, 2013, 06:12:05 AM
Exactly. SDR and knobs are not mutually exclusive. There is also nothing that says SDR has to run on a PC. I expect that SDR is the future - but it will be in a dedicated radio.


Title: RE: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 16, 2013, 10:03:23 AM
Thanks for your comments ZENKI and AA4PB.

It's interesting to me, because I have watched music production, as well as music creation for some genres, go from being all hardware back in the older days to almost completely software and computer-driven today, especially for small studios and independent artists who don't have hundreds of thousands or millions of dollars to set up studio.  One can setup a small computer and software based music studio at home that rivals multi-million dollar big label studios for a tiny fraction of the cost.  Artists can sit down and write software for these systems (such as soft synths) that doesn't even exist out on the market.

By the way, my post was about using computer controllers (usb, bluetooth, wifi, whatever) with knobs and buttons to control SDR through a PC or a headless radio, because I generally agree that the mouse and keyboard is lacking for this use.  As I said before, the mouse and keyboard have specific uses, and where they do not work there is a whole industry full of specialized controllers out there. I have a USB piano keyboard here in my office, as well as a USB drawing pad, for two simple examples.

In my opinion, I would much rather have a controller with all the controls I need laid out in front of me, in addition to having large screens like those on my PC, to manipulate the radio controls, data and ancillary software.  Hunching over a desk to look at a small display on a radio, especially semi-portable radios, is archaic to me and not really necessary with today's technology.  For those who prefer that method of control, I say go for it, but I'll take a big screen and a good ergonomic controller over that any day.

There are many benefits to physically detaching the control mechanism from the actual radio.  For example, I'm no longer locked into a single controller for the life of the radio.  A better controller with more features could come along a few years down the road, and I could simply buy it and get rid of the older controller.  Traditional radios are a big block shape in most cases, and having the controls stuck to the front of that is dictated by the fact that those buttons and knobs are physically attached to the electronics of the radio.  With SDR, that's not the case, so the controls could be a completely separate devices of any kind the user prefers to use.  In your case, you may just want a traditional radio front end.  In mine, I want three big screens on my desk, and sound coming through my nice computer sound system.  

Software interfaces are very flexible, and they encourage further development and experimentation.  "Homebrew" doesn't have to to just mean busting out the soldering iron.  It can also mean tinkering with software development.  If someone comes up with a great new features, or a new way to control an existing feature, you need to have an environment that can easily accommodate change.  With software, you can basically do whatever you want, at least in a prototype scenario, and test your idea immediately.

It will be interesting to see how SDR evolves.  Obviously there's room for manufacturers to cater to everyone by making traditional-style radios, headless SDRs, and hybrids, if they want.  


Title: RE: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 16, 2013, 10:07:34 AM
I'm kind of surprised that SDRs are so expensive.  Eliminating the front end of something like a Flex should make it much, much cheaper to design and manufacture than a traditional radio.


Title: RE: SDR Knobs and Buttons in the future
Post by: AA4PB on August 16, 2013, 02:37:23 PM
The problem with a radio is that it operates at radio frequencies (much higher than A/D, D/A, and DSP can function with current technology) so you can't just connect the antenna to a sound card. The DSP work (filtering, modulation, and demodulation) must be done at frequencies far below the radio's operating frequency. This still requires hardware for the front end of the receiver and final stages of the transmitter. I believe this hardware represents the major cost of an SDR transceiver so moving the modulation, demodulation, and user interface to a PC doesn't reduce the cost all that much even when you don't count the cost of the PC.

That's quite different (I think) than a sound studio application where the highest frequency involved is audio that is well within the capabilities of standard off-the-shelf A/D, D/A, and DSP chips. In spite of this, I still see lots of live mixing applications where a dedicated mixing console is used rather than a PC. The processing is mostly DSP but it is done with firmware in the console rather than software on a general purpose PC. The most used functions are still controlled by knobs and sliders as user input to the firmware. This is where I think amateur radio transceivers are headed in the long run (of course I could be wrong ;D).

The other consideration (in my opinion) is that the majority of hams still want transceivers that are self contained, transportable, and relatively easy to operate. Having a box connected to a PC along with remote tuning and control devices plus dealing with loading and configuring software, drivers, etc. doesn't really lend itself well to that requirement.
 


Title: RE: SDR Knobs and Buttons in the future
Post by: SWL2002 on August 16, 2013, 04:48:04 PM
The problem with a radio is that it operates at radio frequencies (much higher than A/D, D/A, and DSP can function with current technology) so you can't just connect the antenna to a sound card. The DSP work (filtering, modulation, and demodulation) must be done at frequencies far below the radio's operating frequency. This still requires hardware for the front end of the receiver and final stages of the transmitter. I believe this hardware represents the major cost of an SDR transceiver so moving the modulation, demodulation, and user interface to a PC doesn't reduce the cost all that much even when you don't count the cost of the PC.

That's quite different (I think) than a sound studio application where the highest frequency involved is audio that is well within the capabilities of standard off-the-shelf A/D, D/A, and DSP chips. In spite of this, I still see lots of live mixing applications where a dedicated mixing console is used rather than a PC. The processing is mostly DSP but it is done with firmware in the console rather than software on a general purpose PC. The most used functions are still controlled by knobs and sliders as user input to the firmware. This is where I think amateur radio transceivers are headed in the long run (of course I could be wrong ;D).

The other consideration (in my opinion) is that the majority of hams still want transceivers that are self contained, transportable, and relatively easy to operate. Having a box connected to a PC along with remote tuning and control devices plus dealing with loading and configuring software, drivers, etc. doesn't really lend itself well to that requirement.
 


Its pretty simple to understand the cost of a DDC/DUC SDR that performs up there with the best superhet analog designs.  High speed 16 bit ADCs are expensive, something in the neighborhood of $100 ea in smaller quantities.  Compare that to analog solid state devices used in the front end of an analog receiver where those devices cost 25-50 cents each.   You also need DDC/DUC hardware, which is usually implemented in a FPGA.  There are dedicated DDC/DUC integrated circuits but they are developed for the cell phone base station market and do not offer enough dynamic range and alias free bandwidth.  The FPGAs, in which the designer implements a high performing DDC/DUC, can cost from $25 each up to a couple thousand dollars each depending on capabilities.  Still much more expensive than the discrete analog devices used in a superhet or analog direct conversion design.  You also have to throw in software development costs if the SDR manufacturer produces their own software for their hardware (A must, IMO, if you want good integration of a manufacturers hardware with the software).



Title: RE: SDR Knobs and Buttons in the future
Post by: KF6QEX on August 17, 2013, 03:38:36 AM
For Ford, the future is now:
http://www.edn.com/electronics-blogs/automotive-innovation/4418518/Touch-control-not-always-the-best-solution





Title: RE: SDR Knobs and Buttons in the future
Post by: K9IUQ on August 17, 2013, 04:05:30 AM
For Ford, the future is now:
http://www.edn.com/electronics-blogs/automotive-innovation/4418518/Touch-control-not-always-the-best-solution

Ah yes. I have a KIA Soul with a fancy tablet interface and voice controlled Radio.
I hate it. The touch screen is very distracting to use while driving. And the voice control does not work half the time because I do not have a South Korean accent. Give me knobs and old fashioned push button radio any day.

Stan K9IUQ


Title: RE: SDR Knobs and Buttons in the future
Post by: W6RMK on August 17, 2013, 07:37:41 AM
I'm kind of surprised that SDRs are so expensive.  Eliminating the front end of something like a Flex should make it much, much cheaper to design and manufacture than a traditional radio.

It's more that traditional radios are abnormally cheap. Something like an IC-7000 for a bit more than $1000 is an awful lot of radio functionality in a fairly small box.  While the boat anchor folks are justly proud of their units, in real dollars, you spent a lot of bucks for not much in the way of performance.

After that, it's all about mass production. You need fairly high volumes to get the price down. But even with that, it's hard to get the parts count really down.  Sure, one can build a minimalist radio with very few parts (look at the $20 USB tuner based radios), but there will be some performance issues.  On receive, wide open front end means that strong adjacent signals will cause problems.  On transmit, you need output filters for harmonic suppression, and it's hard to get really good carrier/image suppression.  Getting 100W RF power from 2-30 MHz is also challenging at low cost, even with crummy performance.

It all adds up. And it all  takes different pieces of the puzzle, so there's not as much to be gained by higher levels of integration. It's not like you can integrate the HF power amp with the required output filter and put it all on one die in one package.

Even things like power supply bypass capacitors and biasing stuff adds up. The block diagram may only have half a dozen "building blocks", but each of those requires 10-15 passive components hanging around it to make it work.

That said, I think there is scope for some clever design that has not seen the production light of day. The merging of software control that can compensate for DAC and PA non-ideal behavior, and manage things like bias and power supply output on the fly might make transmitters simpler, more efficient, etc.  But that is hard to implement successfully.  Sure you can do cartesian/polar modulation, but it tightly couples the power supply design, the power amplifier, and the low level outputs, whcih makes the design of all of those more tricky.  You don't get to leverage the last 50 years of transistor amplifier design as much.



Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on August 17, 2013, 07:24:57 PM
It's always amazing to witness the utterly obtuse ignorance of reality with those who can't seem to understand that with a Flex or any other thick pipe SDR, the PC that controls the radio is part of the radio, not some incidental ancillary function of your main PC that you use for Facebook and playing Farmville on.

There is absolutely no precedence set by the manufacturers saying that you should not invest in a dedicated PC for controlling your SDR, nor is there any anecdotal evidence of merit that makes that assertion with any sort of validity.

You wouldn't expect to use your Yaesu FT-2000 front panel for logging on to Twitter, so why would you expect to use your Twitter capable PC to run an SDR?

SDR. You either get it or you don't. If you don't, it's not a bad thing, but don't blame it on the rest of us who do get it. We know you're special...


Title: RE: SDR Knobs and Buttons in the future
Post by: KF6QEX on August 18, 2013, 05:04:08 AM
Quote
The other consideration (in my opinion) is that the majority of hams still want transceivers that are self contained, transportable, and relatively easy to operate. Having a box connected to a PC along with remote tuning and control devices plus dealing with loading and configuring software, drivers, etc. doesn't really lend itself well to that requirement.

Nicely summarized



Title: RE: SDR Knobs and Buttons in the future
Post by: K9IUQ on August 18, 2013, 05:46:33 AM
the PC that controls the radio is part of the radio,

Exactly correct. Window Computers were never designed or meant for real time applications like Hamradio. Which of course is one the reasons Flexradios and other SDR's will never be mainstream hamradios.

Stan K9IUQ


Title: RE: SDR Knobs and Buttons in the future
Post by: HAMMYGUY on August 18, 2013, 10:31:14 AM
K5TED my experience with most of my Flex rigs (I've had 2 1000's, 2 1500's and 2 3000's) has been nothing but frustrating.  These radios should have have the CW function blocked on PowerSDR.  Yes I was using a super duper fantastic computer with a zillion megabyte processor with the highly blessed and completely obsolete Firewire interface (unless you're into the music scene).  And yet now it's been proven by the HpSDR folks that PowerSDR IS capable of working with Ethernet. Which completely eliminates the CW lag using my Anan radio which runs on an old POS computer with no issues. 

THAT's why my Flex rigs are all out the door.  CW doesn't work on them unless you're used to,

Press Key "DIT".........................................................................................(wait for it)........................................................................................"Dit" (going out over the air).   


Title: RE: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 18, 2013, 11:36:58 AM
the PC that controls the radio is part of the radio,

Exactly correct. Window Computers were never designed or meant for real time applications like Hamradio. Which of course is one the reasons Flexradios and other SDR's will never be mainstream hamradios.

Stan K9IUQ

PCs are very good at "real time" data stream processing, as long as you are matching your hardware specs with the needs of the software you are using.  My home desktop computer could process a full SDR stream, play a high end 3D video game, and capture live video from a video camera all at the same time, without even breathing hard.  Granted, I built my machine to be a monster, but the reality today is that our computer hardware largely exceeds the demands of today's software.  Especially with quad and hex core processors, cheap memory, and fast hard drives.

Another aspect of problems with SDR seems to be people trying to get them to run on old hardware.  I've only been around here for a short time, but from what I've seen of ham shack photos, and people talking about their computers, there is a lot of ancient computers still being used by hams.  For about $500-600 you could build a new computer with a mid-grade quad core CPU, 8gigs of ram, and a decent hard drive that would process SDR streams and more with no problems at all.

For kicks, here's a picture of my latest build.  I gave myself a $2000 budget to set up a nice gaming rig this year.  I spent $3K on my last one a few years ago, but hardware is cheaper and much more powerful now.  Uses a lot less power too.

http://i.imgur.com/Q5zgF.jpg


Title: RE: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 18, 2013, 11:43:57 AM
I also wanted to add that as far as latency/lag goes for things like CW, using DSP instruments and effects plugins on computers demand low latency as well, in the range of 1-3ms.  If there is a delay, there could be problems with either the computer's ability to keep up, or latency issues/bugs in the software being used.  This is a very subjective situation.

Not all firewire controllers are equal, and if the SDR needs a sound card, there are varying degrees of performance in that area too.  Coming from video gaming on PC's, I would go out and get a good Soundblaster sound card, and purchase a low latency firewire controller like the ones used for music and video production.

I agree that Firewire is obsolete and should be abandoned.  Thunderbolt should be considered.


Title: RE: SDR Knobs and Buttons in the future
Post by: K9IUQ on August 18, 2013, 12:07:33 PM

The problems with PCs in radio, and elsewhere, come from people not paying attention to minimum system requirements for their application.

Not so. Desktop Windows is not a RTOS real time operating system. Use Google, he is your friend and you can also find some RTOS that will do Real Time.

Myself and others had way over the minimum computer requirements for PSDR. And still CW had lag. Still had to worry and contain DPC's. DPC's =A Deferred Procedure Call (DPC) is a Microsoft Windows operating system mechanism which allows high-priority tasks (e.g. an interrupt handler). I assume you understand interrupts and something can not be real time if it interrupts processes...

I tried 3 different computers on PSDR. A full blown i7 with all goodies and fasttt, an i3 laptop loaded and and another computer which I had laying around and do not remember what it was but it was over bare minimum requirements. I also tried a dedicated PC for PSDR. I also tried WIn 7, Vista and Win XP, and Win ME none of which made any difference. As long as Windows uses interrupts SDR software will suffer. Latency, no matter how short affects SDR software. It also made sending CW next to impossible without using an external keyer or (ugh) a keyboard.

I also had to try a couple of different Firewire cards as PSDR only likes one particular chipset of Firewire. You do remember Firewire.  :D

PSDR was also very particular on how you treated it. I lost count of how many times I had to reset the database and or reboot.  ;)

when you own a Flexradio you must have patience and learn how to jump thru hoops..

Stan K9IUQ



 


Title: RE: SDR Knobs and Buttons in the future
Post by: K9IUQ on August 18, 2013, 12:16:17 PM
These radios should have have the CW function blocked on PowerSDR.  Yes I was using a super duper fantastic computer with a zillion megabyte processor with the highly blessed and completely obsolete Firewire interface (unless you're into the music scene). 

CW doesn't work on them unless you're used to,

Press Key "DIT".........................................................................................(wait for it)........................................................................................"Dit" (going out over the air).   

Yep. Flexradios are for SSBers only as I have said many times on this forum. I got rid of my 5K for several reasons and CW performance was at the top of the list.

Stan K9IUQ



Title: RE: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 18, 2013, 12:17:06 PM

The problems with PCs in radio, and elsewhere, come from people not paying attention to minimum system requirements for their application.

Not so. Desktop Windows is not a RTOS real time operating system. Use Google, he is your friend and you can also find some RTOS that will do Real Time.

Myself and others had way over the minimum computer requirements for PSDR. And still CW had lag. Still had to worry and contain DPC's. DPC's =A Deferred Procedure Call (DPC) is a Microsoft Windows operating system mechanism which allows high-priority tasks (e.g. an interrupt handler). I assume you understand interrupts and something can not be real time if it interrupts processes...

I tried 3 different computers on PSDR. A full blown i7 with all goodies and fasttt, an i3 laptop loaded and and another computer which I had laying around and do not remember what it was but it was over bare minimum requirements. I also tried a dedicated PC for PSDR. I also tried WIn 7, Vista and Win XP, and Win ME none of which made any difference. As long as Windows uses interrupts SDR software will suffer. Latency, no matter how short affects SDR software. It also makes sending CW next to impossible without using an external keyer.

I also had to try a couple of different Firewire cards as PSDR only likes one particular chipset of Firewire. You do remember Firewire.  :D

Stan K9IUQ
 

Stan, you do realize that the entire music and movie industry uses Windows and Mac (mostly Mac) for production, yes?  ProTools is one of the most well known software suites for production, and it requires very low latency for timing with digital instruments, recording equipment, synthesizers, DSP plugins and effects, etc.  Unless you think CW requires less than a few milliseconds of latency, then I don't really know why you think you need a special operating system.

I want to be clear that I am not defending Flex here.  I've never touched one.  I'm speaking in terms of computers and somewhat similar low-latency uses for them all over the world.  I want people to understand that standard desktop computers are more than capable of doing very low latency operations with external hardware. If this wasn't true, then they wouldn't be used for music and movie production.

Flex's software/hardware may have issues with CW, I don't know, but that wouldn't be some inherent flaw with PCs that I'm aware of.  I'd be interested to see Flex SDR's latency numbers, if anyone has a link.  Surely they have been tested with CW.


Title: RE: SDR Knobs and Buttons in the future
Post by: W6RMK on August 18, 2013, 12:43:23 PM
the PC that controls the radio is part of the radio,

Exactly correct. Window Computers were never designed or meant for real time applications like Hamradio. Which of course is one the reasons Flexradios and other SDR's will never be mainstream hamradios.

Stan K9IUQ

PCs are very good at "real time" data stream processing, as long as you are matching your hardware specs with the needs of the software you are using.  My home desktop computer could process a full SDR stream, play a high end 3D video game, and capture live video from a video camera all at the same time, without even breathing hard.  Granted, I built my machine to be a monster, but the reality today is that our computer hardware largely exceeds the demands of today's software.  Especially with quad and hex core processors, cheap memory, and fast hard drives.


There's quite a bit more to it than just having fast hardware.  Your software architecture AND the connected hardware needs to be appropriate for the OS. Windows does provide fairly good near real time multimedia support.  However, there's a substantial learning curve on making it play right, and to date, very little ham generated software has made the necessary investment.  Instead, they tend to take wrappers and libraries which *almost* get there and "leave the rest as an exercise for the reader" in good open source tradition. 

It's an expensive proposition to write high quality real time device drivers and the supporting software for Windows (as in multiple work-years of effort).  If you're selling millions of dollars worth of "Call of Duty" or "Skyrim", you can afford to work through all this stuff (and even those guys don't do a perfect job.. there's plenty of bugs in those too).  It is not likely that you're going to get good open-source/free (as in beer) code for Windows to do this stuff, for a variety of reasons, so we wind up with strange hybrids (PowerSDR is an example of such a hybrid) that blend code from a variety of sources and target platforms (dttsp, the DSP core of PowerSDR, was written for *nix type platforms, for instance).


Unfortunately, another aspect which requires substantial sophistication is that the typical "interaction" model with the software for a ham radio doesn't map well into the conventional desktop metaphor, with modal dialogs, focus, etc.  That is, Windows is really designed to have "input" going to one process/window at a time (e.g. you're either typing into a Word document, or an Excel spreadsheet, or another document, but not into all documents at the same time).  You can have multiple output streams fairly well (e.g. play video in one window, look at the output of Word in another, see notices in Outlook or Communicator)

So this raises a problem with designing a radio UI where you want, say, to have a pan display that you can click on, and  a tuning knob (virtual or real), and various other "knobs" (bandwidth, clarifier, volume, etc.).  You can put it all in one window (so that window always has the focus), but that gets awfully cluttered.  And besides, anything that pops up (that text message /IM from someone else, the DX spot message, what have you) tends to pull the focus (unless both applications somehow cooperate).  Digital modes are even trickier.. you have the focus in your text entry/display screen, but you also need to be manipulating the tuning frequency of the radio at the same time.  A lot of programs sort of get around this by implementing "pass through" schemes (e.g. your digimode program can send tuning commands to the radio via CAT or similar)

However, I wouldn't agree with IUQ that ham SDR won't ever be good on a PC.  PC user models are evolving.  There are more and more people who understand how to write good real-time code on Windows, and Windows itself is getting smoother.  Especially if we get rid of the insistence on legacy compatibility that will help.  "I want it to run on my old Win 3.1 machine!"

That said, the near term future for SDRs that use PCs is to have the PC embedded in the radio. Then, the PC can be dedicated to the needed functions, just as embedded PCs are used in oscilloscopes, spectrum analyzers, etc. PC mobos are cheap (<$100) compared to the cost of a fancy ADC/DACs or FPGAs.


Title: RE: SDR Knobs and Buttons in the future
Post by: K9IUQ on August 18, 2013, 01:04:55 PM
 Surely they have been tested with CW.

The end user tests Beta Software for Flexradio. Which is one reason there are so many unhappy and EX-customers.

Flexradio stopped calling their software Beta. Now they use that much better description of "Preview Edition" for the 6000 series. Unless you agree to use Preview Edition software they will not sell you a radio at this time.

I bought my Flex 5K in 2010, almost 3 years after it's introduction. PSDR still was not polished software with basic Features such as a notch filter or FM mode or FSK mode completely missing.

They are doing the same method of operation again. Somewhere on this forum I recently posted a list of the Bugs/Limitations of SmartSdr software. The list was long and I did not list all the Bugs. Flex announced SmartSdr and the 6000 series in May 2012. They took down payments of $1-2K from early adopters. A year and a half of effort later and the software does not have a basic Panafall....

Stan K9IUQ

 


Title: RE: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 18, 2013, 01:08:33 PM
the PC that controls the radio is part of the radio,

Exactly correct. Window Computers were never designed or meant for real time applications like Hamradio. Which of course is one the reasons Flexradios and other SDR's will never be mainstream hamradios.

Stan K9IUQ

PCs are very good at "real time" data stream processing, as long as you are matching your hardware specs with the needs of the software you are using.  My home desktop computer could process a full SDR stream, play a high end 3D video game, and capture live video from a video camera all at the same time, without even breathing hard.  Granted, I built my machine to be a monster, but the reality today is that our computer hardware largely exceeds the demands of today's software.  Especially with quad and hex core processors, cheap memory, and fast hard drives.


There's quite a bit more to it than just having fast hardware.  Your software architecture AND the connected hardware needs to be appropriate for the OS. Windows does provide fairly good near real time multimedia support.  However, there's a substantial learning curve on making it play right, and to date, very little ham generated software has made the necessary investment.  Instead, they tend to take wrappers and libraries which *almost* get there and "leave the rest as an exercise for the reader" in good open source tradition.  

It's an expensive proposition to write high quality real time device drivers and the supporting software for Windows (as in multiple work-years of effort).  If you're selling millions of dollars worth of "Call of Duty" or "Skyrim", you can afford to work through all this stuff (and even those guys don't do a perfect job.. there's plenty of bugs in those too).  It is not likely that you're going to get good open-source/free (as in beer) code for Windows to do this stuff, for a variety of reasons, so we wind up with strange hybrids (PowerSDR is an example of such a hybrid) that blend code from a variety of sources and target platforms (dttsp, the DSP core of PowerSDR, was written for *nix type platforms, for instance).


Unfortunately, another aspect which requires substantial sophistication is that the typical "interaction" model with the software for a ham radio doesn't map well into the conventional desktop metaphor, with modal dialogs, focus, etc.  That is, Windows is really designed to have "input" going to one process/window at a time (e.g. you're either typing into a Word document, or an Excel spreadsheet, or another document, but not into all documents at the same time).  You can have multiple output streams fairly well (e.g. play video in one window, look at the output of Word in another, see notices in Outlook or Communicator)

So this raises a problem with designing a radio UI where you want, say, to have a pan display that you can click on, and  a tuning knob (virtual or real), and various other "knobs" (bandwidth, clarifier, volume, etc.).  You can put it all in one window (so that window always has the focus), but that gets awfully cluttered.  And besides, anything that pops up (that text message /IM from someone else, the DX spot message, what have you) tends to pull the focus (unless both applications somehow cooperate).  Digital modes are even trickier.. you have the focus in your text entry/display screen, but you also need to be manipulating the tuning frequency of the radio at the same time.  A lot of programs sort of get around this by implementing "pass through" schemes (e.g. your digimode program can send tuning commands to the radio via CAT or similar)

However, I wouldn't agree with IUQ that ham SDR won't ever be good on a PC.  PC user models are evolving.  There are more and more people who understand how to write good real-time code on Windows, and Windows itself is getting smoother.  Especially if we get rid of the insistence on legacy compatibility that will help.  "I want it to run on my old Win 3.1 machine!"

That said, the near term future for SDRs that use PCs is to have the PC embedded in the radio. Then, the PC can be dedicated to the needed functions, just as embedded PCs are used in oscilloscopes, spectrum analyzers, etc. PC mobos are cheap (<$100) compared to the cost of a fancy ADC/DACs or FPGAs.

I agree with this in general.  My guess is that the problems with CW have more to do with the limits of the Flex, either in the software and/or hardware.  You covered my main point, which was to say that the problems people are experiencing with latency on SDRs isn't due to some inherent problem with PCs, or their operating systems.

I'm not against the idea of having the radio do all of the heavy processing + thin client capability either, though I would wonder if this would possibly limit future development of new experimental features in radio.  My main interest in SDR is having the larger screens and the potential for custom controllers, not to mention homebrew and experimental software development for radio.

It would be interesting to have some coders who write digital instrument and DSP-plugin software for music production take a look at SDR latency and comment on it. These problems (or similar ones) may have already been solved, complete with open source code projects to learn from.


Title: RE: SDR Knobs and Buttons in the future
Post by: KK6GNP on August 18, 2013, 01:15:37 PM
 Surely they have been tested with CW.

The end user tests Beta Software for Flexradio. Which is one reason there are so many unhappy and EX-customers.

Flexradio stopped calling their software Beta. Now they use that much better description of "Preview Edition" for the 6000 series. Unless you agree to use Preview Edition software they will not sell you a radio at this time.

I bought my Flex 5K in 2010, almost 3 years after it's introduction. PSDR still was not polished software with basic Features such as a notch filter or FM mode or FSK mode completely missing.

They are doing the same method of operation again. Somewhere on this forum I recently posted a list of the Bugs/Limitations of SmartSdr software. The list was long and I did not list all the Bugs. Flex announced SmartSdr and the 6000 series in May 2012. They took down payments of $1-2K from early adopters. A year and a half of effort later and the software does not have a basic Panafall....

Stan K9IUQ


I hear you on this one, Stan.  This has become a common practice in some markets with PC software.  One definitely needs to weigh the pros and cons when purchasing a product from a company with  only beta/preview software available.  I'd like to say that we can bet they will sort all of this out in time, but I don't know them that well, and in my professional life, I deal with software that is in a constant state of beta all the time.  Some of these programs cost multiple tens of thousands of dollars too, but they get away with it because they are the only game in town for a niche market.


Title: RE: SDR Knobs and Buttons in the future
Post by: SWL2002 on August 18, 2013, 01:38:28 PM
Flex's PowerSDR has given SDR a bad name on Windows PCs.  You can write the SDR software to work properly on Windows, but Flex has been unable to do so.  It should be no surprise that the software for the Flex 6000 series is so bad and far behind.  Flex has never been strong in the software programming arena.  Unfortunately, most guys are familiar with only PowerSDR and have not experienced correctly written SDR software on Windows.  Flex and PowerSDR has set a BAD example and it colors most Hams views about SDR at this point.


Title: RE: SDR Knobs and Buttons in the future
Post by: W4HIJ on September 06, 2013, 02:49:46 PM
I actually enjoy operating my SDR with the mouse and keyboard.  I would not take an add on VFO knob type control if it was given to me. I will never ever go back to a traditional knob radio or if I did, I'd use some type of PC control software like HDR to avoid having to tune with a VFO knob. Just because some folks don't have the intelligence and coordination  to operate multiple programs and the SDR program from the PC all at the same time does not mean that everyone suffers from the problem. I typically operate with PowerSDR, logging and digital programs all going at the same time and now that I've gotten used to it, I never have issues with window "focus" or anything else.
73,
Michael, W4HIJ


Title: RE: SDR Knobs and Buttons in the future
Post by: W6RMK on September 08, 2013, 06:07:46 PM
I don't think it's a matter of user skill, familiarity, etc.

It's more a matter of multiple simultaneous processes going on that need to interact (e.g. a digimode program, the radio, and perhaps others).  Frankly, NO consumer operating system's user interface works very well with this; which is why in such situations, one tends to fall back to using multiple computers or writing custom software as a UI front end so all the user interaction is managed consistently.

"windowing" user interfaces (Mac, Windows, Gnome, KDE, X11.. all the same) all have this issue with "to which process does that keystroke, mouse click, etc go", and the choices tend to be biased towards a "desktop/document" model: if you have sheets of paper on your (physical) table top, and a pencil, the input goes to the one which the pencil is touching.   But most computer GUIs do this as a two step process: select which window to send input to (e.g. giving it the focus), then send the input to the process attached to that window.  Where it gets real ugly is when an underlying process wants attention, and its user interaction space/window is hidden.  (viz, the bouncing icon on the Mac dock).  You can either automatically direct the focus to the process requesting input, or notify the user, and let them decide.  With Windows, you can do either, and there's no real consistency among applications.

Indeed, tuning with a mouse is convenient, although I find that if you need to "set a value exactly" a manual knob with "clicks" or typing the number is easier. And it's not like knob interfaces are all that wonderful either (e.g. HP/Agilent must have had 5 or 6 different ways of changing the step size for the knob on the front panel of instruments over the last 20 years).  There's also a whole thing in UI design about moving from one modality to another.  For instance, it's usually faster for a user to do a series of mouse clicks than it is to mouse, then keyboard, then go back to the mouse; and vice versa.

getting it "right" in the sense of being facile for the greatest number of users is non-trivial and expensive.


Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on September 08, 2013, 08:49:47 PM
PowerSDR is easy to use. Digi modes with FLDigi or PowerSDR is a simple matter.

1. When using digi modes such as PSK, MFSK, etc., one generally does not need to fiddle much with the radio controls, since most digi operation occurs within predefined slots. Once you've clicked on the slot, set your drive and output power, there's really no need to go back to the radio console other than to adjust speaker volume. Logging programs run easily side by side with the digi program, and in some cases, such as DM-780/MiniDeluxe/PSDR, are completely integrated. Most everything you need runs from the DM-780 screen.

2. Did I mention that PowerSDR is very easy to use?

3. Proper radio/PC configuration is up to the user, not the manufacturer. Failure to dedicate a proper PC system to the radio may leave the user baffled and disgruntled. While sometimes unintended or unanticipated, this is all self inflicted pain.

4. PowerSDR is really, seriously, easy to use. It works really well with other programs.

5. Expert Electronics... Bring on the knobbed SDR!

6. It has been well documented that some CW users do not enjoy the CW options available for use with the second gen Flex radios. It is well documented and therefore, complaining about it is a bit pointless, since it has been well documented for some time. Some CW users do well with the radio. Some drivers do well with the Ford Fiesta. I do not, for reasons that are well documented by car review mags.



Title: RE: SDR Knobs and Buttons in the future
Post by: W6RMK on September 09, 2013, 10:08:26 AM

3. Proper radio/PC configuration is up to the user, not the manufacturer. Failure to dedicate a proper PC system to the radio may leave the user baffled and disgruntled. While sometimes unintended or unanticipated, this is all self inflicted pain.


This is true for experimenter, developer environments.  It is decidedly not true for most end user environments. 

I would venture that the single biggest complaint, comment, feedback from users of PC software of any type is the complexity of installation and configuration in a multi application environment. Even more so after applications have been removed, updated, etc over some period of time.  There's a reason the term DLL hell exists.

Users are not sys admins, nor should they require the skills of one.

Dedicating a PC per application is a viable strategy in some environments, and is how I see the SDR evolving. Embed the thing and don't try to make one machine do multiple things, then there is less chance for incompatibility, resource contention, etc.  The software developer can then focus on designing and producing good interfaces between boxes, because just like good fences, they make for good neighbors.


Title: RE: SDR Knobs and Buttons in the future
Post by: M0HCN on September 09, 2013, 11:16:50 AM
I have written both hard RT safety critical code and music signal processing code, and neither are easy....

My suspicion is that a big part of the CW issues come down to sending the key status to the PC at far too low a rate, consider if a packet contains say 128 I/Q samples, but only a couple of bits for key state, then the keyer code has no way to know when the key was actually pressed, and thus no way to ensure that the delay between the key and the sidetone is constant rather then variable.

If the key data was sent as a side channel running at the same rate as the samples, then the keyer code could contrive to introduce a constant delay between contact and sidetone which I suspect would work better (This is how most soft synths work with MIDI, you set the hardware up to timestamp the midi messages with a clock derived from the soundcard and you don't respond to the note as soon as you can (Which is variable) you respond after a fixed time interval that you can always meet reliably).

There is a very similar issue with MIDI instruments, in that a few ms of latency is not a major problem (Sound after all only travels at ~1ft/ms), but latency jitter of the same order can make it completely unplayable.

The real answer for CW is to move the keyer into a tiny little bit of VHDL running at Mhz rates on the radios gate array, and to have the gate array use an NCO to produce the sidetone and RF envelope, that way you are assured of deterministic behavior with timing jitter measured in the sub microsecond region. 

General purpose computers really are actually NOT very good at short deadline soft realtime, they like to process data in largeish blocks rather then doing the work in interrupt context (Which something like a TMS320C6 can easily handle), so you cannot really do sample by sample processing, instead being forced into working with blocks of several hundred samples. If you try to make a general purpose machine run with short buffers and correspondingly very high interrupt rates what tends to happen is that throughput goes way down and there is a threshold below which you start to miss deadlines due to the OS having its own ideas about priorities.

Can it be done better on a general purpose box, sure it can, but if designing a radio it is easier to stick a couple of modest dsp or even arm parts in there and use something like FreeRtos rather then Windows, offload the FFT to some VHDL and it does not take a huge amount of processor power.

Software development is inherently expensive and difficult, and for a product expected to sell in the thousands rather then the millions it may well be that the $20 BOM cost of putting a dedicated processor core on the board is worthwhile, then you have the interesting possibilities of things like the Cyclone V some of which have on board hardwired arm cores.

73, Dan.


Title: RE: SDR Knobs and Buttons in the future
Post by: W4HIJ on September 09, 2013, 04:23:22 PM

3. Proper radio/PC configuration is up to the user, not the manufacturer. Failure to dedicate a proper PC system to the radio may leave the user baffled and disgruntled. While sometimes unintended or unanticipated, this is all self inflicted pain.


This is true for experimenter, developer environments.  It is decidedly not true for most end user environments. 

I would venture that the single biggest complaint, comment, feedback from users of PC software of any type is the complexity of installation and configuration in a multi application environment. Even more so after applications have been removed, updated, etc over some period of time.  There's a reason the term DLL hell exists.

Users are not sys admins, nor should they require the skills of one.


I will say again, as I've said many times before, if you don't know your way around a PC environment pretty dang well then you have no business buying an SDR in the first place.  Like it or not, they are not usually "plug and play" and I don't really think people should expect them to be at this point in time. They may never be although I think maybe the Flex 6000 series will be, given time for the software to mature. If someone wants to be able to hook 12v and coax, a mic and a key and start yakking away to their buddies about their latest operation then they need to stick with the plain old tired and boring knob radio designs that have been available for years. Myself, I enjoy the work and thinking involved in configuring a properly functioning SDR station.
73,
Michael, W4HIJ


Title: RE: SDR Knobs and Buttons in the future
Post by: AK7V on September 09, 2013, 04:45:09 PM
I think software is a very young engineering discipline, easily accessible, and not as refined as - for example - electrical engineering or mechanical engineering.  Lots of software is tragically buggy and unreliable.  Not as much discipline taken in its creation (perhaps because there aren't material costs, manufacturing costs/effort, etc. to deal with).  And anyone can do it -- I was writing programs in grade school (but not ones that anyone should rely on!).

I like that my radios aren't going to blue screen or freeze or crash or stutter or conflict.


Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on September 09, 2013, 04:59:29 PM
" if you don't know your way around a PC environment pretty dang well then you have no business buying an SDR in the first place. "

Similar comments were likely made back in the early days of amateur radio, when there were no "off-the-shelf" transceivers.

A second generation consumer grade SDR is a breeze to implement and operate with a very few exceptions. One only needs to read the requirements and follow the instructions, and understand that the PC is an integral part of the radio, and treat it as such. It is the knobs. You wouldn't try to chip ice with the front panel of a FTDX5000, so why would you expect to get email on your SDR?






Title: RE: SDR Knobs and Buttons in the future
Post by: M1BJR on September 11, 2013, 05:07:23 PM
I think software is a very young engineering discipline, easily accessible, and not as refined as - for example - electrical engineering or mechanical engineering.  Lots of software is tragically buggy and unreliable.  Not as much discipline taken in its creation (perhaps because there aren't material costs, manufacturing costs/effort, etc. to deal with).  And anyone can do it -- I was writing programs in grade school (but not ones that anyone should rely on!).

Excellent point, well made.

But there have been an equal number of badly designed 'off the shelf' analogue parts with well resourced corporations behind them.

Same issues but in a different package.... the difference with software is you can fix it without even opening the box.

Steve.


Title: RE: SDR Knobs and Buttons in the future
Post by: W6RMK on September 13, 2013, 06:04:38 AM
Same issues but in a different package.... the difference with software is you can fix it without even opening the box.

Assuming the box has the underlying capabilities needed.  This might be the case with using consumer PCs and their OSes (Win, Linux, Mac)  as a platform: getting desired performance may not be possible in that framework without changing/adding hardware (e.g. the hardware keyer/DDS mentioned above).

 This is a huge issue in the professional SDR world: historically, one bought a radio which would perform certain functions, and it either did or it didn't.  With SDRs, you have the problem of specifying and buying a hardware platform to meet some speculative needs of some future software which has not been written yet.

Flex and VB+Windows is a fine example. The very first VB software + extremely simple hardware (IQ demod/mod from soundcard) did what it was expected to do (basically SSB on a 1 Watt radio), but didn't do a lot of other things it was desired to do.  PowerSDR was the next attempt, while staying within the same PC+windows+simple RF hardware platform, and is very successful at some things, not so successful at others, especially where hard realtime issues come into play (missing a buffer on output leads to CW tone coming out of radio on Tx; variable latency means using RF for CW sidetone is impractical);  A change in the HW platform (MIDI for keying information) helped a bit, but the Windows environment is very tough to do hard real time in (and Linux or Mac OS are really no better).

I think it is *possible* to do SDR on a PC platform with a consumer operating system, but it's going to be very expensive.  And it''s so easy today to move some of the functionality off the PC and into something else, that's the logical step.  Big FPGAs are pretty expensive still, so the USRP model may not be optimum (although, a low end USRP isn't a whole lot more expensive than the original Flex 3 board set); but it's certainly heading in the right direction. 

SDR tinkering on the part of hams has also moved away from where there's a significant fraction of the buyers interested in writing/modifying the DSP code.  The beauty (in my mind) of the original SDR1K and VB was that it was incredibly inexpensive for someone to "get their feet wet". The codebase was small and limited and could be understood in a day. A similarly simple software backend to one of the $20 USB pods would be the same; but can't transmit easily. 

Today, though SDR is perceived as "super duper multi function transceiver" competing with the big iron from the Japanese mfrs. And to get there requires an enormous amount of software, and hardware help to solve the real time problem.

But for the original "hack the DSP code" market, the actual platform is almost unimportant.  Writing BASIC or C code is easier than VHDL or Verilog, but in all cases, there are cheap parts and free software tools to work with.


Title: RE: SDR Knobs and Buttons in the future
Post by: K9IUQ on September 13, 2013, 06:28:53 AM

 not so successful at others, especially where hard realtime issues come into play (missing a buffer on output leads to CW tone coming out of radio on Tx; variable latency means using RF for CW sidetone is impractical); 

 the Windows environment is very tough to do hard real time in (and Linux or Mac OS are really no better).

And to get there requires an enormous amount of software, and hardware help to solve the real time problem.

I made the same point you just did concerning RTOS. I was told Real Time is a piece of cake on PC's or Macs. These comments are earlier in this thread.

Now we can not have it both ways. Someone here is wrong....

Stan K9IUQ


Title: RE: SDR Knobs and Buttons in the future
Post by: M0HCN on September 13, 2013, 09:40:48 AM
Realtime has an interesting definition in the software game, it does not (necessarily) mean fast, it means there is a deadline and it WILL be met, no matter what.

A classical example of a realtime system is payroll processing, that money HAS to move on the specified day or really bad things happen to a lot of people. The deadline is once a month, so this is not fast, but it is immovable.

Now for our purposes we are looking at short deadline hard realtime, which even more then the other sort is not trivial, if we want to keep the latency in the say 10ms range, and it takes 1ms to get the data to and from the modulator, and our DSP takes say 5ms to do whatever it does to a block of data, then any delay in executing the dsp thread greater then 4ms will result in a missed deadline, and all sorts of things can cause delays.

Higher priority interrupts (SMM Mode springs to mind), lock contention (Another thread has a lock on some required resource), memory exhaustion (This is why one should NEVER allocate or free memory from a RT thread, it can always block), cache lines pingponging between cores, even the memory subsystem can throttle a pc in response to temperature, and for a worst case analysis you have to add up all the possible delay causes and ensure that the total comes in below the limit required time to meet the deadline.

Typically most general purpose operating systems have an average latency in the sub ms region, but with large spikes caused by things like contended locks in task management structures and interactions between the memory and IO subsytems, a hard RTOS guarantees that these spikes will never exceed a defined length, no commodity os makes ANY guarantee about the maximum scheduling latency.

Further, latency and throughput are goals that tend to work in opposition, low latency systems tend to not be particularly high throughput, so folks optimizing for a compute heavy load will trade poor scheduling latency for more throughput every time.

Doing reliable realtime at latency in the single digit realm on a commodity PC is tough, to the point that the guys doing serious audio and video editing get **very** picky about what hardware they will buy for the purpose. Even things like video cards can sometimes be shockingly badly behaved, locking the bus for entire milliseconds to get a few extra frames per second on the 'benchmark' in some random gamer magazine.

Now all that said, reasonable reliability as opposed to hard realtime is much easier, at least if you are a hacker and not above getting your hands dirty, but even this in the ms latency region can cause severe bouts of headscratching when you move the work to a new pc, selling and supporting such products is a bit if a nightmare.

Making SDR economic at the cheap HF set level needs the tech to become sufficiently mature for someone to be willing to commit to an ASIC rather then doing the work in a commodity FPGA, and at that point there is a question about just how 'software defined' the set really is, it becomes more of a 'digital radio' then a software defined one.
Eventually someone will pull the trigger on this, but not until they figure they have a product with at least a 5 year market life at a few thousand units a year, and the technology is still moving too fast for that to be the case.


73 Dan.


Title: RE: SDR Knobs and Buttons in the future
Post by: KF6QEX on September 15, 2013, 03:15:58 PM
Quote
I made the same point you just did concerning RTOS. I was told Real Time is a piece of cake on PC's or Macs. These comments are earlier in this thread.

Now we can not have it both ways. Someone here is wrong....

It is,depending on your definition or "real time" what kind of cake and the size of the piece of cake.
"pretty fast" and "almost instantly" "barely noticable" and "negligible delay" don't count as "real time".
THe easiest test to perform is this: I stumbled on it accidentally when each kid turned on the TVs really loud so I could hear both "at the same time".
Two different model satellite TV receivers tuned to the same tv program, create an echo when you listen. One of the two lags behind just enough to create the echo effect.
I expect with a "conventional radio and a SDR tuned to the same station side by side, the SDR will have a noticable delay varying depending on the model/type of SDR.
I also know that any number of "conventional" radios tuned to the same station have no audible delay
As for music production, USB microphones for example, include a 3.5mm jack for  monitoring  in "real time" before the signal enters the digital chain.
ie: http://www.musiciansfriend.com/pro-audio/rode-microphones-podcaster-usb-microphone has one and this one actually mentions the delay /latency issue : http://www.musiciansfriend.com/pro-audio/blue-yeti-usb-microphone

Quote
...The Yeti utilizes a high quality analog-to-digital converter to send incredible audio fidelity directly into your computer, a built-in headphone amplifier for zero-latency monitoring, and simple controls for headphone volume, ... 

I call all this phenomenon "asychnronous real time". Of course when you have two realities that are out of step with each other, although they make pills for that for humans, they don't have a pill of radios yet :)


Title: RE: SDR Knobs and Buttons in the future
Post by: M0HCN on September 15, 2013, 03:40:08 PM
Ah, you mean low latency, not realtime, definitions matter when discussing this stuff....

Odds are that that headphone jack on the usb mic is actually a digital mixer behind the ADC feeding a DAC and exists mostly so that the buffering in the PC does not cause comb filtering due to delay relative to the bone conduction path in the singers head.
The reason for putting a DAC in the mic is that attempting to use an ADC on one clock with a DAC on another is a can of worms, so best avoided to avoid customer support headaches.

The ADC and DAC will introduce about a ms of latency, due to the decimation and interpolation FIR networks, but the buffering to go from sample by sample processing (as you would do with a real DSP or in a gate array) to blocks of hundreds of samples as used in typical PC processing can add 10s of ms to the latency numbers, this moves the combing down from Khz to a few hundred Hz and makes it become very objectionable. 

In the context of a radio, for SSB latency of the up to say 50ms or so level is clearly a non issue, same for most data modes, as long as it is compensated for some of the EME modes.

CW is probably the only place it matters, and there are well known ways to solve this or at least to give the operator a choice of trade offs (Linear phase filters will ALWAYS introduce more group delay then non linear phase ones for example).

Low latency audio is a very tough problem on PCs, it can be done, but man what a pain.

73 Dan.


Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on September 15, 2013, 06:16:14 PM
Latency with SDR is a non-issue except for CW.



Title: RE: SDR Knobs and Buttons in the future
Post by: AB2YC on September 18, 2013, 06:18:19 AM
To the OP congratulations on getting your License.

I also have been in the IT field for over 20 years and realize PCs will be with us for some time.

It was SDR that drew me back into ham radio, it truly is the future.
You will always find those who resist change, just side step them and move on.

One point where SDR shines is the ability to quickly change the entire interface by just changing the computer controlling it.
I foresee a point where the manufactures will offer a control head that will basically be the interface replacing the PC.
and an example of this is the K3 by Elecraft, my understanding is that it is actually a SDR based radio with a hard interface.

Being and IT guy myself I don't have a real issue with the PC interface and find it a whole lot easier to do all the inter-connections
"Virtually" (serial, audio, etc), need another port just add another "Virtual" one (I don't need to open the case or run a cable).

I would suspect that most IT guys or technology guys would not have an issue with SDR, we already understand that you need a
decent PC with a clean OS. I'm more of a Linux guy when it comes to apps requiring computer control of hardware (I also run CNC).
I was a bit reluctant at first to use MS Windows to run a radio, but it (my Flex-1500) has been running fine for me so that reluctance is gone.

Again congratulations on getting your license, and welcome to the world of SDR.







Title: RE: SDR Knobs and Buttons in the future
Post by: N4OI on September 18, 2013, 07:00:22 PM
Latency with SDR is a non-issue except for CW.

For some of us, this statement effectively reads, "Latency with SDR is a non-issue except for [ham radio]."

73


Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on September 18, 2013, 09:46:50 PM
Latency with SDR is a non-issue except for CW.

For some of us, this statement effectively reads, "Latency with SDR is a non-issue except for [ham radio]."

73

Low ground clearance of the Corvette is a non-issue except for off-roading.


Title: RE: SDR Knobs and Buttons in the future
Post by: N4OI on September 19, 2013, 04:16:49 AM
Latency with SDR is a non-issue except for CW.

For some of us, this statement effectively reads, "Latency with SDR is a non-issue except for [ham radio]."

73

Low ground clearance of the Corvette is a non-issue except for off-roading.

And you will not find off-roading anywhere in the Corvette's published features or specs -- perhaps SDR vendors should re-label their CW buttons to "Amp Tune" ...   ;D

73


Title: RE: SDR Knobs and Buttons in the future
Post by: W1JKA on September 19, 2013, 04:50:25 AM
  SDR newbie here, what kind of performance could I expect if I put an SDR mobile in my corvette and limited myself to secondary roads only? I plan to use a screwdriver for an antenna. Thanks


Title: RE: SDR Knobs and Buttons in the future
Post by: K9IUQ on September 19, 2013, 07:10:34 AM
perhaps SDR vendors should re-label their CW buttons to "Amp Tune" ...   ;D

Perhaps it would be EVEN better if they eliminated the CW button,FSK button,and Digi buttons..

SDRs are for SSBers who like to brag and tell everyone how great their radio/audio works.. All other hams need not apply.

Stan K9IUQ


Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on September 20, 2013, 06:26:53 PM
Perhaps those who can't operate SDR's shouldn't purchase them. We'll still talk to them. Some of us may use CW when we "talk" to them. We will undoubtedly be using much superior SDR/Digi setups than a typical knob rig/patch cord/external modem/isolation transformer concoction user. We won't need a patch cord. It'll just flow, trouble-free, digitally from PC to SDR.

Nice.

It's really the only way to go unless you insist on touching just two wires together to communicate. Nothing wrong with that, but it's a bit beneath the technological advantages of an SDR.


Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on September 20, 2013, 06:32:24 PM
Latency with SDR is a non-issue except for CW.

For some of us, this statement effectively reads, "Latency with SDR is a non-issue except for [ham radio]."

73


Low ground clearance of the Corvette is a non-issue except for off-roading.

And you will not find off-roading anywhere in the Corvette's published features or specs -- perhaps SDR vendors should re-label their CW buttons to "Amp Tune" ...   ;D

73

True. What you will find is a gearshifter that has the same designations as a Jeep gearshifter. Totally different vehicles. Same "D" on the shifter. (or 1, 2, 3, 4, etc.)

Perhaps Chevrolet should relabel the "D" to "Go Really Fast" and Jeep should relabel to "Go Really Slow Up A Telephone Pole"


Title: RE: SDR Knobs and Buttons in the future
Post by: N4OI on September 20, 2013, 08:17:29 PM
Latency with SDR is a non-issue except for CW.

For some of us, this statement effectively reads, "Latency with SDR is a non-issue except for [ham radio]."

73


Low ground clearance of the Corvette is a non-issue except for off-roading.

And you will not find off-roading anywhere in the Corvette's published features or specs -- perhaps SDR vendors should re-label their CW buttons to "Amp Tune" ...   ;D

73

True. What you will find is a gearshifter that has the same designations as a Jeep gearshifter. Totally different vehicles. Same "D" on the shifter. (or 1, 2, 3, 4, etc.)

Perhaps Chevrolet should relabel the "D" to "Go Really Fast" and Jeep should relabel to "Go Really Slow Up A Telephone Pole"

My Jeep does indeed have a "D" on the "gear shifter," but it also has another lever connected to a military-grade transfer case to select from three variations of 4WD.  (All analogies break down at some point, but I love the legs this one has!)   ;D

73


Title: RE: SDR Knobs and Buttons in the future
Post by: N4OI on September 21, 2013, 05:39:26 AM
Latency with SDR is a non-issue except for CW.

For some of us, this statement effectively reads, "Latency with SDR is a non-issue except for [ham radio]."

73


Low ground clearance of the Corvette is a non-issue except for off-roading.

And you will not find off-roading anywhere in the Corvette's published features or specs -- perhaps SDR vendors should re-label their CW buttons to "Amp Tune" ...   ;D

73

True. What you will find is a gearshifter that has the same designations as a Jeep gearshifter. Totally different vehicles. Same "D" on the shifter. (or 1, 2, 3, 4, etc.)

Perhaps Chevrolet should relabel the "D" to "Go Really Fast" and Jeep should relabel to "Go Really Slow Up A Telephone Pole"

My Jeep does indeed have a "D" on the "gear shifter," but it also has another lever connected to a military-grade transfer case to select from three variations of 4WD.  (All analogies break down at some point, but I love the legs this one has!)   ;D

73

Oh, and I think one of the 4WD options is labeled "QSK"  ;D !!


Title: RE: SDR Knobs and Buttons in the future
Post by: W6RMK on September 21, 2013, 07:27:33 AM
Ah, you mean low latency, not realtime, definitions matter when discussing this stuff....



In the context of a radio, for SSB latency of the up to say 50ms or so level is clearly a non issue, same for most data modes, as long as it is compensated for some of the EME modes.

CW is probably the only place it matters, and there are well known ways to solve this or at least to give the operator a choice of trade offs (Linear phase filters will ALWAYS introduce more group delay then non linear phase ones for example).

Low latency audio is a very tough problem on PCs, it can be done, but man what a pain.

Latency, on the RF path to the other end, is almost a non-issue regardless of mode *as long as the latency is constant*.  It takes 100 ms to propagate to the other side of the world, so adding 10-20-30 or even 100 ms isn't going to make a huge difference.

If the latency on the RF path varies randomly, though, it makes it very difficult to copy CW.

Where most people object to the latency thing is when trying to monitor their own CW transmission using a receiver.  There, the tens of ms latency bites you, because it's far enough out of sync to confuse you (the "singing on the PA in a stadium without earplugs" problem).

One can use a keyer or generate the sidetone some other way, but then you aren't listening to your own signal.


Title: RE: SDR Knobs and Buttons in the future
Post by: N4OI on September 23, 2013, 02:27:21 AM
Ah, you mean low latency, not realtime, definitions matter when discussing this stuff....



In the context of a radio, for SSB latency of the up to say 50ms or so level is clearly a non issue, same for most data modes, as long as it is compensated for some of the EME modes.

CW is probably the only place it matters, and there are well known ways to solve this or at least to give the operator a choice of trade offs (Linear phase filters will ALWAYS introduce more group delay then non linear phase ones for example).

Low latency audio is a very tough problem on PCs, it can be done, but man what a pain.

Latency, on the RF path to the other end, is almost a non-issue regardless of mode *as long as the latency is constant*.  It takes 100 ms to propagate to the other side of the world, so adding 10-20-30 or even 100 ms isn't going to make a huge difference.

If the latency on the RF path varies randomly, though, it makes it very difficult to copy CW.

Where most people object to the latency thing is when trying to monitor their own CW transmission using a receiver.  There, the tens of ms latency bites you, because it's far enough out of sync to confuse you (the "singing on the PA in a stadium without earplugs" problem).

One can use a keyer or generate the sidetone some other way, but then you aren't listening to your own signal.

I do not believe the issue is the inability to listen to one's own signal.  There is just no way to compensate for significant latency, whether constant or not, and still have good QSK...  After experiencing QSK from a K3 or any of the older Ten-Tec radios, you're not going to "keep 'em down on the farm" with a keyer-generated sidetone either.....   

73



Title: RE: SDR Knobs and Buttons in the future
Post by: M0HCN on September 23, 2013, 11:05:26 AM
The key question is what is significant?

I would guess that 10ms (as long as it is constant) probably is not significant (That is going to be in the ballpark for vacuum relay T/R switch and rx desense recovery time on a conventional rig, and actually a well crafted PC program should come close to this as long as the network frames are not too big.

20ms, 50ms? I have no idea, but I would bet the threshold is greater then 10ms for almost everyone and greater then 20ms for the vast majority of ops. 

Regards, Dan.


Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on September 23, 2013, 10:05:15 PM
If the main objection to SDR is that CW ops can't listen to their own clicks, then I'd add this...

For about 15 years, I was accustomed to listening to myself over an air monitor. That way, I could hear myself as heard by listeners. With the advent of digital STL links, the latency was enough to make realtime listening impossible. We adjusted to listening to ourselves off console audio.

With the present SDR tech, and the inherent latency, it is impossible to listen live.

The overwhelming majority of amateur grade xcvrs do not offer a "MONITOR" function, yet we get along just fine.

It seems as if the insistence of CW ops to have the ability to listen to themselves "realtime" is just a crutch and excuse to malign current SDR tech.

Use a keyer and get along, or get left behind.



Title: RE: SDR Knobs and Buttons in the future
Post by: AK7V on September 24, 2013, 09:20:41 AM
...
It seems as if the insistence of CW ops to have the ability to listen to themselves "realtime" is just a crutch and excuse to malign current SDR tech.

Use a keyer and get along, or get left behind.


I haven't used an SDR, but based on what I'm reading, I'd guess that the QSK isn't that great because of the latency.  For me, excellent QSK at mid to high speeds is something I love about CW and wouldn't want to sacrifice.  It's not so much listening to ourselves "realtime," but being able to hear the band "realtime" between code elements.

I'm not worried about being "left behind."  HF radio is old news all together, we've all been "left behind" already.  :)


Title: RE: SDR Knobs and Buttons in the future
Post by: AB7R on September 24, 2013, 10:50:41 AM
I don't think there are any modern radios out there in the past 20 years that do not have a CW side tone monitor.  I have a 6700 and use an external keyer for contesting purposes but any radio that supports CW should have a usable side tone monitor available and QSK capability.  I understand from the Insider reports that there has been much focus on QSK and CW in general that I hope will be in the Ver. 1.0 release.

73
Greg
AB7R


Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on September 25, 2013, 07:07:34 PM
I don't think there are any modern radios out there in the past 20 years that do not have a CW side tone monitor.  I have a 6700 and use an external keyer for contesting purposes but any radio that supports CW should have a usable side tone monitor available and QSK capability.  I understand from the Insider reports that there has been much focus on QSK and CW in general that I hope will be in the Ver. 1.0 release.

73
Greg
AB7R

Good point. I would say that QSK is purely a contest requirement and has no bearing on day to day typical amateur radio use as a whole. The solution is that those who plan to contest seek something besides an SDR, since at this juncture and for the foreseeable future, DSP based rigs simply will NOT be capable of delivering true QSK. Someday, maybe, but for now, the SDR is the realm of phone, digi, SSTV, and casual CW users. That's just the way it is, and no amount of harping will fix that. The only solution is a DSP platform that has no latency.

We don't have that capability now. We won't have that capability within the next 10 years. We won't have that capability until digital signal processing makes some leap of performance that is, at this time, inconceivable.


Title: RE: SDR Knobs and Buttons in the future
Post by: AK7V on September 26, 2013, 10:35:23 AM
I don't think there are any modern radios out there in the past 20 years that do not have a CW side tone monitor.  I have a 6700 and use an external keyer for contesting purposes but any radio that supports CW should have a usable side tone monitor available and QSK capability.  I understand from the Insider reports that there has been much focus on QSK and CW in general that I hope will be in the Ver. 1.0 release.

73
Greg
AB7R

Good point. I would say that QSK is purely a contest requirement and has no bearing on day to day typical amateur radio use as a whole. The solution is that those who plan to contest seek something besides an SDR, since at this juncture and for the foreseeable future, DSP based rigs simply will NOT be capable of delivering true QSK. Someday, maybe, but for now, the SDR is the realm of phone, digi, SSTV, and casual CW users. That's just the way it is, and no amount of harping will fix that. The only solution is a DSP platform that has no latency.

We don't have that capability now. We won't have that capability within the next 10 years. We won't have that capability until digital signal processing makes some leap of performance that is, at this time, inconceivable.


I'm guessing you're not a high speed CW op, then.  QSK is not "purely a contest requirement."


Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on September 26, 2013, 05:41:33 PM
If you're not contesting or in some sort of CW traffic net, then why do you need to hear in between your characters?

No, I'm not a high speed CW op. I admire those who are. SDR is not for them at this juncture.

 


Title: RE: SDR Knobs and Buttons in the future
Post by: N4OI on September 27, 2013, 04:33:55 AM
If you're not contesting or in some sort of CW traffic net, then why do you need to hear in between your characters?
[...]

When I am responding to a CQ, or calling CQ, QSK allows me to stop sending as soon as I hear another station -- that helps me avoid me becoming QRM.   Also, when I am in a QSO, I can hear someone wanting to break in or comment and turn it over.  (I assume phone ops. use VOX for some of the same reasons.)

The only time I go to semi-breakin operation is when the QRN is so high that I cannot hear my sidetone -- and that is very rare.

QSK is essential for me; every radio I have, from my Rockmite to my K3, has it. 

73


Title: RE: SDR Knobs and Buttons in the future
Post by: M0HCN on September 27, 2013, 01:40:17 PM
[quote or=AB7R link=topic=91646.msg702581#msg702581 date=1380045041]
We don't have that capability now. We won't have that capability within the next 10 years. We won't have that capability until digital signal processing makes some leap of performance that is, at this time, inconceivable.
[/quote]
Disagree, we can do this today, its just that we don't because the SDR scene is wedded to general purpose operating systems on commodity hardware and often has a poorly thought out keying input.

Lets say 10ms is a reasonable latency, and that getting to and from an I/Q pair at a reasonable symbol rate takes 2 of those ms (Probably realistic for the CIC and decimator/interpolator chains to do their thing).

Lets say we are getting an I/Q sample every 10us (100KHz I/Q sample rate), and that we are doing the work in a DSP interrupt handler on a core closely coupled to the FPGA fabric (Cyclone 5 for example can have a dual core hard IP arm  on the die) or at least on the same board.

Now we are processing a sample every 10us, and ignoring filter latencies can turn it around in 1.01ms aerial to audio dac or vice versa.
This leaves the filtering, which is surely going to be some kind of FIR/IIR mix, and if we switch to low latency mode is NOT going to be linear phase (For the same reason narrow crystal filters are not usually linear phase, causality makes the group delay excessive), filter delay is a fact of life in either analogue or digital filters, and the only reason we notice it more in digital is because we choose to optimize for other things (Constant group delay being the big one).

Note that 10ms is almost certainly faster then any rig not using diode switches can go from rx to tx without risking hot switching at least one relay, and is only slightly longer then the rise time of a well behaved keying envelope.

73 Dan.


Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on September 27, 2013, 07:06:35 PM
"Disagree, we can do this today, its just that we don't because the SDR scene is wedded to general purpose operating systems on commodity hardware and often has a poorly thought out keying input. "

Add in the extra 8ms for the trip from the client to the router to the SDR and back.

Dependency on a networked client console will have inherent latencies that simply cannot be eliminated.


Title: RE: SDR Knobs and Buttons in the future
Post by: M0HCN on September 28, 2013, 02:58:44 AM
Which is why I mentioned closely coupling a processor to the gate array.

Actually, 8ms would be shockingly poor for a uncontended local link, with preemption on in the kernel and tuned interrupt processing priorities, I am seeing network latencies in the 400us region (And could probably do better).

Still best to hook the processor directly to the gate array fabric, but networking is not a show stopper.

Regards, Dan.


Title: RE: SDR Knobs and Buttons in the future
Post by: W6RMK on September 29, 2013, 09:29:00 PM
W
Actually, 8ms would be shockingly poor for a uncontended local link,

That's a sort of typical ping time for a household WiFi network.
64 bytes from 192.168.1.1: icmp_seq=0 ttl=64 time=6.162 ms
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=6.279 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=1.911 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=1.228 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=3.053 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=7.518 ms
64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=6.028 ms
64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=4.803 ms
64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=6.370 ms
64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=1.276 ms

Just goes to show that one probably shouldn't use WiFi (competing with everything else) to do hard real time with <10ms latency requirements.

Wired should be <1 ms for the same scenario.



Title: RE: SDR Knobs and Buttons in the future
Post by: M0HCN on September 30, 2013, 10:41:06 AM
Short deadline RT over wifi? "Doctor, it hurts when I do this".....

Not surely a reasonable thing to do if carting a reasonable chunk of spectrum around as an I/Q sample stream.

I have found that some so called gig-e cards have really shonky drivers that cannot keep up if you come even close to saturating the link, so you have to be a little picky wrt hardware if you want things to work well, but it was ever thus.

Regards, Dan.


Title: RE: SDR Knobs and Buttons in the future
Post by: N9RO on September 30, 2013, 11:17:47 AM
If you can accept all the issues with using ICMP (ping) and want to just focus on numbers for comparison here is a comparison of doing a ping on Wi-Fi vs. Hardwire Ethernet:

On uncontended Wi-Fi network
Reply from 192.168.1.1: bytes=32 time=4ms TTL=64
Reply from 192.168.1.1: bytes=32 time=7ms TTL=64
Reply from 192.168.1.1: bytes=32 time=4ms TTL=64
Reply from 192.168.1.1: bytes=32 time=3ms TTL=64
=========== Sniffer Trace Wi-Fi (Leaving Timestamp Only ==============
+---------+---------------+----------+
18:08:08,468,564   ETHER
+---------+---------------+----------+
18:08:09,283,727   ETHER
===============================================================

On switch Ethernet (wired) network
Reply from 10.10.30.105: bytes=32 time<1ms TTL=128
Reply from 10.10.30.105: bytes=32 time<1ms TTL=128
Reply from 10.10.30.105: bytes=32 time<1ms TTL=128
Reply from 10.10.30.105: bytes=32 time<1ms TTL=128
=========== Sniffer Trace Ether (Leaving Timestamp Only ===============
+---------+---------------+----------+
18:12:24,094,109   ETHER
+---------+---------------+----------+
18:12:24,094,151   ETHER
+---------+---------------+----------+
===============================================================

If hams understood 802.11 they would see this would be the very LAST choice to operate a thick client SDR on.  Most network testing and metrics are done using wired networks, Wi-Fi is just too painful and unreliable to make any meaningful decision.  In addition, Wi-Fi was intended for MOBILE use never intended for applications continuously streaming large volumes of IQ data. 

73,
Tim  N9RO


Title: RE: SDR Knobs and Buttons in the future
Post by: K5TED on September 30, 2013, 05:13:26 PM
Do hams truly not understand 802.11?



Title: RE: SDR Knobs and Buttons in the future
Post by: AB2YC on November 30, 2013, 04:35:43 AM
I recently connected a Hercules DJ Controller to my radio to control it.

Look here for info - http://www.dh1tw.de/powersdr-ui (http://www.dh1tw.de/powersdr-ui)

Now I have Knobs to control my radio


Title: RE: SDR Knobs and Buttons in the future
Post by: KF6TIL on January 08, 2014, 07:52:37 PM
I'm new to these forums and still learning about SDR.  Just getting back into ham radio after many years.  As a software developer SDR should be right up my alley!

Pardon my ignorance, but could a Microsoft HID interface such as this: http://www.leobodnar.com/shop/index.php?main_page=product_info&cPath=66&products_id=204 be used to build your own VFO dials, etc.?

As one who started with a 40's vintage Hallicrafters receiver back in the 60's, I enjoy the "feel" of a nicely balanced dial to navigate the air waves.  If the above interface will work, it would be pretty simple to build my own control panel.


Title: RE: SDR Knobs and Buttons in the future
Post by: KE7TMA on January 08, 2014, 08:04:13 PM
I for one am quite surprised that modern SDRs do not include MIDI, as there are many MIDI hardware control surfaces (knobs, switches, dials, etc) that would adapt really well to amateur radio, and they aren't very expensive either.