eHam

eHam Forums => SWL (Shortwave Listening) => Topic started by: NI0Z on August 27, 2013, 06:25:24 PM



Title: SDR SWL's
Post by: NI0Z on August 27, 2013, 06:25:24 PM
How many here are SWLers on SDRs?

Just curious where that sits now days!


Title: RE: SDR SWL's
Post by: SWL2002 on August 28, 2013, 09:44:01 AM
Lots of them.  Probably more than Hams using SDRs.  Unfortunately, you won't hear from a lot of SWLers on this website unless they are also Hams.  Not too many non-Ham SWLers visit this site.


Title: RE: SDR SWL's
Post by: KAPT4560 on August 30, 2013, 04:46:59 AM
 I build and test tactical SDRs for a job. One radio platform can fit many different applications.
 I don't have one personally, but have been interested in the WiNradio line of products and have been looking for a good reasonable, used one. I could never justify a new one to the XYL.
 I have had fun using this web-based SDR:
http://websdr.ewi.utwente.nl:8901/


Title: RE: SDR SWL's
Post by: N5INP on August 30, 2013, 05:13:06 AM
How many here are SWLers on SDRs?

Just curious where that sits now days!

I'm into it again at least until I get an HF rig.

I resurrected a PC I had in my closet to devote to the radios and got my NRD-535 receiver to work with HDSDR (at least controlling it in one direction).  :) I had to dig down into a junk box to find an rs-232 cable (with 25 pin male end!) and a null modem adapter, but it's working. The proc is a dual-core with 4 G memory and Win 7/64 and it's working OK with HDSDR. It's pretty neat. Although due to a quirk in the way the old NRD-535 works, the control won't work in both directions at once with the Omnirig app, it does control the HDSDR when tuning and changing modes. So I can just tune along and the display follows perfectly.

It's really a nice thing to have. I don't even look at the radio now. I just tune along and watch for interesting signals instead of listening for them. The dongle is really sensitive too. I was going back and forth between the radio audio and the SDR audio trying to compare quality and more than once I had to look down to remind myself which device I was actually listening to. It's amazing that a small device that cost just $20 and some free software can compete with a $1,600 communications rx (in 1990 dollars)!

I have a small numeric keypad on order so I can set the keyboard aside. I really don't need the keyboard most of the time, but I can use the numeric keypad to enter frequencies and I can also set the Windoze password to a number too. That will free up desk space.

(https://lh5.googleusercontent.com/-thGxlUumdXY/UiCKznT69kI/AAAAAAAAAXI/DTzDF_9HTuc/s640/rigs.jpg)


Title: RE: SDR SWL's
Post by: W7AIT on September 07, 2013, 09:47:06 PM
My Opinion and observed facts:  I have both CommRadio CR-1 SDR, AND a ICOM IC-R75.  The SDR is full of problems, needed(s) many software changes, and so far at least one required return to the factory for hardware and more software fixes.  It still has problems especially with tuning, ease of use, connector interfacing, and especially AGC problems (maybe there isn't any?), I can only say it overloads and distorts very easily. 

Just too many things changing with those SDR radios.  I needed a radio to listen too, not modify, repair, change, and change again (MRCA).  There are still many open issues with the SDR.  I quickly tired with all the fiddling, changes, sending back for constant repair, and incessant software updates, of which I screwed up several.  So I bought a new ICOM IC-R75.
The R75 gets a A+, especially with the PAR END FED SWL antenna installed at about 30 feet high and it performs excellent!  I also conducted A/B testing comparing the PAR with BW65 and CHA250 antennas.  Also ran EZNEC simulations on them all.  Actual data surprised me how well the PAR END FED works.  And of course I ran A/B testing on the ICOM IC-R75 vs. the CR-1.
The wining ticket is ICOM IC-R75 and a PAR END FED antenna.  Now I can listen to Short Wave for hours with no problems and not worry about yet still another fiddle software change.  My Opinion and observed facts.  Use / toss as you wish. 



Title: RE: SDR SWL's
Post by: WV4I on September 08, 2013, 03:30:03 AM
I'm apparently one of the relative few around the world with my SDR-IQ online, op SWL/WV4I, available thru SDR-Radio, which is a free download, use V 1.5! The Receive Ensemble II HF, and several other SDR's are also compatible with SDR-Radio and its associated terminal program. To the thread topic, I see far more use in the AM and SW BCST spectrums from remote users than tuning to Ham bands. You can see the SDR-Radio worldwide status map, get download and setup info, at http://sdrspace.com/
Enjoy.


Title: RE: SDR SWL's
Post by: N5INP on September 08, 2013, 05:37:57 AM
My Opinion and observed facts:  I have both CommRadio CR-1 SDR, AND a ICOM IC-R75.  The SDR is full of problems, needed(s) many software changes, and so far at least one required return to the factory for hardware and more software fixes.  It still has problems especially with tuning, ease of use, connector interfacing, and especially AGC problems (maybe there isn't any?), I can only say it overloads and distorts very easily.  


I'm not using anything anywhere near as expensive as that CR-1. I'm using a $20 Terratec dongle and a $30 Ham-it-up Up Converter, and as I said it seems to work extremely well. Maybe you should try the less expensive route.  :)


Title: RE: SDR SWL's
Post by: K0OD on September 08, 2013, 09:45:07 AM
I can't explain why anyone would want the ever-buggy and featureless CR-1 which now is priced at $650.  Users are finally rejoicing that the latest software upgrade MAY have gotten its AGC working. Analog radios have had fully functioning AVCs since the late-1920s!

One explanation is that many SWLs collect radios, more than use them. Shortwave Hoarders might be a better term. Beats me why anyone needs 50 or more shortwave receivers.

Quote
Maybe you should try the less expensive route.

Yep, decent basic reception comes cheap these days. I'm amazed how well my $170 Yaesu VX3  2m/440 HT performs as a receiver across it broad range of AM BCB to a Gig.

That extra receiving capability is free! And it has functioning AGC.


Title: RE: SDR SWL's
Post by: RENTON481 on September 09, 2013, 02:42:59 AM
I'm one of those non-ham SWL's that comes here, and I do not have an SDR, and never intend to, for a bunch of reasons -- the first one being that I already have several MW and SW radios that work quite well.  

I just don't see the point in having a receiver that is tied to a computer, or pulls in a gazillion frequencies at once, when you still can only listen to one frequency at a time.  SDR may be for other people, but not for me.  I know the displays look pretty, and some DXers use the SDR waterfalls to ID certain utility transmissions, but I'm not into that.  

If I was going to spend more money on the radio hobby I'd get a high grade tabletop receiver like an R75 or R8 (which would be cool, but which I really don't need to enjoy the hobby), or get a license and buy an HF ham rig.


Title: RE: SDR SWL's
Post by: N5INP on September 09, 2013, 05:02:29 AM
I just don't see the point in having a receiver that is tied to a computer, or pulls in a gazillion frequencies at once, when you still can only listen to one frequency at a time.

Quote
I know the displays look pretty, and some DXers use the SDR waterfalls to ID certain utility transmissions, ... 

Well, what modern shortwave rx isn't tried to a computer anyway? Don't most of them have processors inside? So, you are really not thinking about the meaning of "I just don't see the point in having a receiver that is tied to a computer ..." They are all "tied to a computer" inside anyway.  :P

But - the second quote from your post answers the first one. Since getting an SDR, and using HDSDR as the program, some of time I don't even listen, I look at the spectrum/waterfall display and see what's going on in a 200 - 500 kHz slice of the band. I can see signals popping up here and there. If you were searching for new signals with a normal radio you would have to depend on pure luck to run across an intermittent transmission as you turned the dial. Also, you can see signals that sweep the bands and see their time vs. freq. characteristics. in the waterfall as well as their modulation fingerprint. Another type of transmission that is interesting to watch (yes I mean watch not listen to) is the OTH radar signals that come up in a certain part of the band. You simply can't see that with a normal radio.

Since the radio is effectively software upgradable it's more versatile than a totally hardware radio (or one that has a proc. that can't be upgraded).

So, I think your view is very limited. SDR adds a whole new aspect to investigating the shortwave bands - your eyes, and I may have had the same view you have had I not tried out this technology. Now I'm totally on-board and very impressed with what it can do. The other point - it doesn't cost that much to get into since I think most people already have a PC.


Title: RE: SDR SWL's
Post by: K0OD on September 09, 2013, 09:23:09 AM
Renton says elsewhere that his hobby funds are limited. Then he realizes something that escapes most SWLs and some  hams. For many listeners a basic receiver attached to a few dollars worth of random wire can be totally adequate on lower frequencies where atmospheric noise is the limiting factor. My 1937 Zenith 5 tube BCB/SW receiver still excels for many purposes. So I'm with Renton.

Now, assuming the SWL is into the gamut of radio including digital reception, there are many advantages (and a few disadvantages) that come with high end SDRs. Panadaptors are costly but very useful for a multitude of purposes including spotting openings on higher bands. They add a useful visual dimension that is much more than eye candy. SDRs have virtually no drift and some can show frequencies to a single Hertz, or even less with a built-in scope. That can be useful for some arcane digital reception.

For listeners like Renton there are some advantages to SDRs too. My Flex-5000 offers ten stock AM bandwidths for traditional broadcast reception. Custom filters, including notches, can be easily created on the fly. The radio's Synchronous AM detection often increases listening enjoyment especially on longwave AM signals for some reason. Its audio can be adjusted almost infinitely. Sometimes SDRs offer advantageous noise reduction.

Will you pick up weak distant broadcast stations better on a high end SDR compared with Renton's $100 portables? Probably not, especially on bands below about 15 to 20 MHz.   



Title: RE: SDR SWL's
Post by: SWL535 on September 09, 2013, 03:28:45 PM
I'm a non-Ham SWLer. I have a Kenwood R-5000 and an JRC 535D.  I love them both but bought a little FiFi SDR to play with.
So far as a Utility DXer I find the SDR and it's panoramic display VERY useful. I expect to purchase a QS1R, a WinRadio Excalibur
or Excalibur Pro. All 3 of these of course have an even wider display being direct conversion.

I would never give up my traditional receivers as there still is a dial twirler in me but after getting the SDR I think
they will spend much of their life as frequency monitors like HFDL, etc.

Ken


Title: RE: SDR SWL's
Post by: K5TED on September 09, 2013, 05:55:33 PM
Renton says elsewhere that his hobby funds are limited. Then he realizes something that escapes most SWLs and some  hams. For many listeners a basic receiver attached to a few dollars worth of random wire can be totally adequate on lower frequencies where atmospheric noise is the limiting factor. My 1937 Zenith 5 tube BCB/SW receiver still excels for many purposes. So I'm with Renton.

Now, assuming the SWL is into the gamut of radio including digital reception, there are many advantages (and a few disadvantages) that come with high end SDRs. Panadaptors are costly but very useful for a multitude of purposes including spotting openings on higher bands. They add a useful visual dimension that is much more than eye candy. SDRs have virtually no drift and some can show frequencies to a single Hertz, or even less with a built-in scope. That can be useful for some arcane digital reception.

For listeners like Renton there are some advantages to SDRs too. My Flex-5000 offers ten stock AM bandwidths for traditional broadcast reception. Custom filters, including notches, can be easily created on the fly. The radio's Synchronous AM detection often increases listening enjoyment especially on longwave AM signals for some reason. Its audio can be adjusted almost infinitely. Sometimes SDRs offer advantageous noise reduction.

Will you pick up weak distant broadcast stations better on a high end SDR compared with Renton's $100 portables? Probably not, especially on bands below about 15 to 20 MHz.   



Here's a L/R comparison of a Icom PCR-100 (analog radio using an IF tap and HDSDR, on the Left Channel) vs. a Flex 3000(Right channel) listening to a very weak 1620kHz Radio Progreso, both on the same antenna, simultaneously.

http://k5ted.net/mp3/radioprogreso1620TOHLRA.mp3

Not a whole lot of difference...


Title: RE: SDR SWL's
Post by: K0OD on September 09, 2013, 07:10:49 PM
Quote
Not a whole lot of difference...

Right channel sounded a bit better. Left was slightly muffled at times.


Title: RE: SDR SWL's
Post by: RENTON481 on September 13, 2013, 12:36:01 AM
N5INP: I realise my view may be limited, and admittedly, it is my own self limiting at play here. 

I enjoy searching through the HF spectrum, whether it's hunting through the 20 or 40 meter ham bands, the SWBC bands, or the MW broadcast band, frequency by frequency, listening closely to what's there. 

I don't think I would get the same enjoyment from an SDR.  Perhaps I could -- I'm sure there is a way to use an SDR in that manner.  But to concentrate on a few frequencies at a time one doesn't need an SDR.

I think SDRs are probably better for the utility hunters, or ham contesters, or maybe those who want to get everything in one: HF transceiver, unlimited filters, broad spectrum monitoring, DSP, etc. that an SDR provides (as K0OD mentioned).  I understand some of the higher end HF transceivers have spectrum monitoring and some of the features SDRs have, but it looks more limited than what an SDR provides.  So I can see the appeal.

Also, maybe I'm a bit of a purist.  I'm trying to learn CW -- and I actually listen to the CW bands, trying to pull out IDs on frequencies with 2-3 CW transmissions on them (obviously, digital portables have wide filters for CW).  It's a challenge, but it's also fun.

But with a computer you don't even have to know how to 'read' CW.  Your computer can do it for you.  It can not only listen, but it can also sometimes decode it for you. This is just one example where I sort of have a problem with computers doing our listening for us.  To me it takes some of the fun out of it. 

I know to others, using an SDR makes it more rewarding, because they enjoy maximizing the technology.  I know some of the heavy duty MW DXers use SDR's.  If they miss a DX session, they've got the file to go over later on.  It's almost like time-shift listening to the entire band.  I can see how that could be a plus.  But I get more enjoyment monitoring a frequency, sometimes for a half hour at a time.  I've gotten some good DX that way.  It's just my way of doing things.  ;D

Chris
Renton481


Title: RE: SDR SWL's
Post by: KE7TMA on September 16, 2013, 06:33:07 PM
I'm one of those non-ham SWL's that comes here, and I do not have an SDR, and never intend to, for a bunch of reasons -- the first one being that I already have several MW and SW radios that work quite well.  

I just don't see the point in having a receiver that is tied to a computer, or pulls in a gazillion frequencies at once, when you still can only listen to one frequency at a time.  SDR may be for other people, but not for me.  I know the displays look pretty, and some DXers use the SDR waterfalls to ID certain utility transmissions, but I'm not into that.  

If I was going to spend more money on the radio hobby I'd get a high grade tabletop receiver like an R75 or R8 (which would be cool, but which I really don't need to enjoy the hobby), or get a license and buy an HF ham rig.

I use my KX3 for SWL with regularity, and it's not tied to a computer unless I want it to be.  I do agree that a radio that needs a computer to function is kind of kludgy.


Title: RE: SDR SWL's
Post by: N5INP on September 16, 2013, 06:47:28 PM
I do agree that a radio that needs a computer to function is kind of kludgy.

Ahem ... then by your own definition the KX3 is kludgy, because it has to have it's internal computer to function.

This is what's inside it -

mcu 18F87K22

 CPU

    Up to 16 MIPS Performance
    Operating Speed up to 64 MHz
    Operating Voltage Range: 1.8 to 5.5V
    8 X 8 Single-Cycle Hardware Multiplier
    Three Internal Oscillators: 31 kHz, 500 kHz, 16 MHz

http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en546891


Title: RE: SDR SWL's
Post by: W1JKA on September 17, 2013, 09:50:06 AM
   I went looking for a new short wave receiver to replace my aging FRG-7700 and found a very nice one by ICOM the IC-7200 which was less expensive than the stand alone SWRs that I had been looking at.


Title: RE: SDR SWL's
Post by: KB8VIV on September 17, 2013, 11:06:43 AM
I'm a ham, but enjoy all aspects of radio, from hamming to swl'ing.  To be honest, though, I spend 99% of my time listening, and so I took the plunge a while back and bought an Afedri sdr.  For $250, you quite a competent little sdr, as a matter of fact, I've not turned on me bloody ts-870 since I hooked up the Afedri.

The bandscope is especially usefull in spoting stations.  Lots of examples of my catches can be found here: http://m.youtube.com/channel/UCBUv3aLtkrAoeFQA6mDo2uw

I tend to chase Numbers and Pirate stations.

kb8viv


Title: RE: SDR SWL's
Post by: KE7TMA on September 17, 2013, 03:42:31 PM
I do agree that a radio that needs a computer to function is kind of kludgy.

Ahem ... then by your own definition the KX3 is kludgy, because it has to have it's internal computer to function.

This is what's inside it -

mcu 18F87K22

 CPU

    Up to 16 MIPS Performance
    Operating Speed up to 64 MHz
    Operating Voltage Range: 1.8 to 5.5V
    8 X 8 Single-Cycle Hardware Multiplier
    Three Internal Oscillators: 31 kHz, 500 kHz, 16 MHz

http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en546891

Which HF radio produced nowadays doesn't have a computer inside of it?  Something has to drive that shiny display, the logic for the IF DSP, etc.  I thought it would be obvious even to a pedant that I meant, and external computer and monitor.


Title: RE: SDR SWL's
Post by: K0OD on September 21, 2013, 12:06:23 PM
A QS1R SDR in action...

YT video shows reception of the LYQ beacon on 529 KHz. 22 seconds into the brief clip the listener re-shapes the pass band to reduce QRM from 530, probably a highway information station. Best to watch in the full screen mode.  The bandscope also shows  a stronger AM broadcast station up the band on 540.000.0
http://www.youtube.com/watch?v=0EU4elCbVzw

Foreign stations between our standard 10 KHz spacing would be easily spotable even if their audio was obliterated by sidebands of nearby broadcasters.  I can sometimes see a well defined blip on 1521 KHz which is probably the Saudi Arabian 500 KW broadcaster right next to many U.S. stations on 1520. 


Title: RE: SDR SWL's
Post by: KB5UBI on September 27, 2013, 03:03:07 PM
I have a Softrock SDR receiver attached to a PC at the other end of the house from the HAM Shack. Mostly I use it to check propagation, but sometimes I find myself cruising the non-amateur HF bands.


Title: RE: SDR SWL's
Post by: KE7TMA on October 14, 2013, 07:58:11 PM
How many here are SWLers on SDRs?

Just curious where that sits now days!

I'm into it again at least until I get an HF rig.

I resurrected a PC I had in my closet to devote to the radios and got my NRD-535 receiver to work with HDSDR (at least controlling it in one direction).  :) I had to dig down into a junk box to find an rs-232 cable (with 25 pin male end!) and a null modem adapter, but it's working. The proc is a dual-core with 4 G memory and Win 7/64 and it's working OK with HDSDR. It's pretty neat. Although due to a quirk in the way the old NRD-535 works, the control won't work in both directions at once with the Omnirig app, it does control the HDSDR when tuning and changing modes. So I can just tune along and the display follows perfectly.

It's really a nice thing to have. I don't even look at the radio now. I just tune along and watch for interesting signals instead of listening for them. The dongle is really sensitive too. I was going back and forth between the radio audio and the SDR audio trying to compare quality and more than once I had to look down to remind myself which device I was actually listening to. It's amazing that a small device that cost just $20 and some free software can compete with a $1,600 communications rx (in 1990 dollars)!

I have a small numeric keypad on order so I can set the keyboard aside. I really don't need the keyboard most of the time, but I can use the numeric keypad to enter frequencies and I can also set the Windoze password to a number too. That will free up desk space.

(https://lh5.googleusercontent.com/-thGxlUumdXY/UiCKznT69kI/AAAAAAAAAXI/DTzDF_9HTuc/s640/rigs.jpg)

While typical SDRs do work well for SWL activities under decent conditions, their lack of manual RF gain control, somewhat simplistic filtering, lack of DNR and noise blankers, and so forth really make them a pain in the ass after a while.  I'd take the NRD-535 over a new-fangled SDR receiver any day for pure listening comfort.