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Author Topic: In the age of "virtual technical parity" Do Specs matter anymore?  (Read 6007 times)
WA4D
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« on: March 06, 2013, 09:17:56 AM »

There seems to be a growing consensus among reviewers of tech products: computer specs -- processor, memory, display resolution --  Specs don't really matter anymore.

A seemingly never-ending debate between audio subjectivists versus objectivists . The former rely on their ears (and subjective impressions) when evaluating radio/audio components, while the latter argue that technical specs tell the true story.

Subjective opinions claim all sorts of dramatic sound differences among end-user transcievers components (like roofing filters, IMD curves and  various Mics etc.)

The problems with the subjectivist approach are well known ,  Sometimes you hear a guy on HF telling the other Ham, “Leave it right there, don’t touch anything!”  What?Huh  Yet what you heard is completely unacceptable.

The bigger question may be: "Do Spec's matter anymore?"

Is there a substantial and noticeable difference between any of the HF or VHF/UHF rigs built in the last 5 years? Little if any. Oh  a particular model may have been poorly designed or a bad batch in a production run. (Example: the Icom 7600 RF Finals) but for the most part the difference is meaningless to most operators.

And Reviews! Many formal  reviews are based around specs. Does anyone really read in depth the mind numbingly bland QST technical reviews of a new rig?   Even QST to some degree has rolled back their more technical emphasis in articles as the new crowd doesn't really know (or care?) much about what’s under the box. Hams (like Tablet users and Smart phone buyers) want features and user operability. Software flexibility matters far more than the noise floor number.

Yet to some users, Spec’s DO matter and are good for bragging rights and they make for some interesting arguments on occasion. But for the vast majority of Hams who don't know what IMD means or how to read the slope of a Roofing Filter, it’s all just “noise”

Ok, be honest. Can you even hear the difference between a rig with a 90 db dynamic range and one with 110+?  

We have reached virtual technical parity among consumer level ham rigs.The differences between rigs are nearly indistinquishable for same class radios.  And this techno homogenization points at the dimminishing need for technicians.  (a job function that is rapidly  disappearing.} VHF rigs are now like potato chips. It breaks? Throw it away and get a new one.  There are those who love to propagate the myth that ham radio is a deeply technical hobby.   But when it's all said and done, most specs are manufacturers window dressing.  Noise if you will.

The Spec is not yet dead, but it's influence wains

mike HAMQTH:  http://www.hamqth.com/wa4d
« Last Edit: March 06, 2013, 09:35:16 AM by WA4D » Logged
KD0REQ
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« Reply #1 on: March 06, 2013, 10:29:26 AM »

hasn't stopped the arguments among audiofools, and it won't here, either.

it all depends on what is good enough for you and your location.  if X works well and costs $3000 less than Y, is X good enough for you?

if it is really, really important that you have 140 dB rejection and the extra 0.004 uV sensitivity in a S4 noise location, hey, it's your money.  platinum edition Yugo, but have fun showing it off.
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NO2A
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« Reply #2 on: March 06, 2013, 11:51:48 AM »

One problem that exists today is part tolerances. Many components coming from China are off,according to an engineer who posts on this site. I`m sure he`s right. Is that 10 ohm resister really 10 ohms? Now imagine if that was used in medical equipment. Some of those values are way off. Last summer I bought a backwash hose for my pool filter. Got it home and connected it. It lasted a few minutes before bursting wide open. It couldn`t handle the high pressure. Broke apart at the seams,even had multiple pinholes in it. It was the cheapest vinyl I`ve ever seen. Then I looked at the package,"Made in China." A complete waste of $25. I thought to myself,"Thanks to you politicians."
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N0YXB
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« Reply #3 on: March 06, 2013, 01:32:36 PM »

[I thought to myself,"Thanks to you politicians."

Don't forget to thank the business community (in particular the big box retailers) and consumers (who shop at big box retailers) while you are at it.

But I sympathize, it's difficult to consistently buy U.S. made goods, no matter how much one tries.
« Last Edit: March 06, 2013, 01:39:20 PM by N0YXB » Logged
G3RZP
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« Reply #4 on: March 07, 2013, 03:03:30 AM »

Specs do matter. Where it falls down is that too many people don't understand what they mean. I've done measurements of noise level and received signal level over a number of hours on 7 MHz which is the most demanding band in Europe. I live in an 'ITU rural area' as far as noise goes, and the measurements made at sunspot min and something approaching sunspot max say that you need a total dynamic range of about 95 to 100dB. Anything more, you can't use.  What you do need is an attenuator so you can fix where the range starts.

Now that dynamic range is composite - i.e. it is either phase noise limited or intermodulation limited or possibly both. In fact, the biggest limitation tends to be phase noise rather than IMD.

Where you do run into trouble is the wide band noise from so many of the big transmitters in BC band there, and there's nothing you can do about that.
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NO2A
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« Reply #5 on: March 07, 2013, 10:28:18 AM »

I`ve seen many times when ARRL was testing a rig that didn`t meet claimed specs,then having it returned to the manufacturer. Curious how many roll of the assembly line like that. For years Uniden has had a cb radio they claim has 7 watts audio ouput. That sounds great,but I have yet to see any radio with that much audio. I would love to see that on the test bench.
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WA4D
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« Reply #6 on: March 07, 2013, 12:10:50 PM »

Interesting observation Peter.  Thanks!
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G3RZP
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« Reply #7 on: March 08, 2013, 04:10:38 AM »

You can find the results of the measurements in a QEX sometime in 2002 or 3 (first lot) and  the later ones in an NCJ of 2009 or 2010.

73

Peter G3RZP
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M0HCN
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« Reply #8 on: March 09, 2013, 12:53:51 PM »

You only need as much radio as your site requires, and there really are no bad Rx chains these days (Tx chains are another story however...).

I would second Peters comment on PN usually being the limiting factor, and add that even more commonly the limiting factor is not PN but the operator!
We have all seen the wailing that results when someones 3Khz wide IF with AGC on gets stomped while he is trying to listen to a 50Hz wide PSK signal, better narrow IF filters would have fixed that (And odds are he has them, just has not used them). 

Now the technical reviews on the transmit chains are useful when considering a purchase if only in a "Can I in good conscience put a rig measuring -20db PEP IMD3 on the air?" kind of sense.

The technical reviews are mostly interesting when combined with details of the radios architecture as a learning tool for those of us who will insist on homebrewing with 0402 and the odd BGA.
Having good measured data for various approaches informs design when you are playing in the workshop (And there are still fun things to play with that no commercial rig does).

Regards, Dan.
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TANAKASAN
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« Reply #9 on: March 10, 2013, 04:49:22 AM »

An interesting post. A long list of specifications only matters if the people reading the article can understand their meaning, and that ability is starting to wane. The latest 'product reviews' in QST seem to concentrate more on useability than anything else and they have even stopped showing pictures inside a rig so that we can get some idea of the construction quality.

I think the biggest problem is that we have reached a technological plateau and the manufacturers are either unwilling or unable to push the envelope. The same thing can be seen in the computer industry, I'm typing this on a six year old laptop that doesn't need to be replaced because it does what I want and if I should purchase a new machine it will only provide a minor increase in performance. To sell rigs (and computers, and flat screen TVs) the manufacturers therefore resort to adding bells and whistles through software in an effort to add perceived value.

So, what is the present state of affairs?

1) Receivers are about as good as they can be, although transmitters could be improved. The last truly revolutionary antenna idea was probably the StepIR.

2) Progress in technology seems to have slowed.

3) The people using these devices (computers or ham radio rigs) are being reduced to appliance operators because of the technical complexity coupled with software walled gardens.

4) The standard of technical education is falling with some purchasers of equipment unable to understand or appreciate the nature of their purchase. Specifications are ignored and new features are left switched off due to an inability to read and understand the manual.

Two weeks ago I had to explain to a licenced amateur  the difference between the emitter, collector and base connections on a transistor. This is a young man who owns a top of the line HF rig which he purchased the day after passing his exam. Something tells me he never read the specifications before purchase.

Tanakasan
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WB0KSL
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« Reply #10 on: March 10, 2013, 07:59:59 AM »

While I generally agree, I would temper the conclusion in paragraph 4.  Today's manuals are often poorly organized and poorly written.  With the complexity of new radios, the manuals are of necessity more complex as well.  That should not be an excuse, however, to cut corners in the technical writing that is essential for the new owner.

73 de wb0ksl, John
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M0HCN
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« Reply #11 on: March 10, 2013, 10:54:46 AM »

I am not sure we really have reached a technological plateau, I can think of quite a few things that could usefully be experimented with to push the state of the art in even HF radio....

Where are the commercial ham rigs that can do synchronous sampling of multiple aerials, this would allow for example beam forming to be done in the DSP rather then by physically rotating a beam, hell lock the things to a GPS time and frequency standard and you could use a network of them to do long baseline interferometry (Great for dx!) and even bistatic radar by looking at the reflections from known shortwave broadcasters and beacons. A modern GPU can handle the beamforming equations in real time, but where are the radios?
Such a thing on a continent wide scale would (with timestamped data and accurate aerial position fixes) rock for doing propagation studies.

4 sync inputs connected to a 4 square would let you electronically steer the beam on receive and would even let you simultaneously steer multiple lobes on the same or different frequencies (Think one toward the DX, another toward Italy and do some maths to put the null where it will do the most good....), the same concept applies on transmit but requires 4 PA strips and LPF networks making it a bit of a pain.   

Or how about hooking a whole pile of 'sampler head' units to a field full of E field probes and using a whole pile of correlation to pick the signal out of the local noise sources...

The business of mixers and IF amps may be as good as it needs to be, but I would make a case that the LO is still a problem, and that nobody is doing things that look at the possibilities of whole system as opposed to a simple radio.

Then we have "high end" rigs that bottle it and consider a class A PA to be state of the art? Sorry but less then 50% efficiency, come on guys Granburg was doing better then that 30 years back....

It has always been the case that the new and interesting stuff is difficult and not available commercially, that is why it is new and interesting.

QEX, Dubus and friends are still publishing good stuff even if the reviews of the latest black box are pretty much uninteresting.

73, Dan.
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AD4U
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« Reply #12 on: March 10, 2013, 05:54:11 PM »

I have posted this before, but around 5 years ago I was looking for a new challenge.  Being a boat anchor collector and restorer I fired up my Drake 2B receiver and matching Drake 2NT 50 watt crystal controlled transmitter and started operating CW.  In 5 years of off and on operating only on 40 meter CW I have worked 293 countries and all states.  The antenna is a half wave dipole up about 70 feet.

This post is not about bragging.  Sure we all would like to have one of the $10,000 rigs, but most of us never will.

My 50 year old all tube Drake 2B receiver can "hear" most anything at my QTH that any other receiver can "hear", at least on 40 meters.  What I am trying to say (I guess) is one can work lots of DX with a 50 year old transmitter and a GOOD 50 year old receiver.

Dick  AD4U
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G3RZP
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« Reply #13 on: March 11, 2013, 02:47:17 AM »

>Receivers are about as good as they can be, although transmitters could be improved.<

At HF, it's more a case of 'as good as they need to be', rather than 'as can be'.

Although there are things that can be done with multiple antennas, most amateurs are severely space limited. I would have a problem putting up a 4 square for 7MHz, although I have over half an acre, and most amateurs have a LOT less, even in the US. Many amateurs in the UK do not even have the room for a G5RV with its 102 foot top - my last house, on  a new estate, had a big garden for such a property - it was 80 feet long!

Improving transmitters is not quite so easy. It will need either Polar Loop or Cartesian feedback - the latter is probably the easiest if an amplifier is to be added later, but needs some very good mixers in the feedback chain. Even so, the limit is likely to be wideband amplitude noise.

A tube tx and CW seems the easiest option for improving things....BC610 anyone?
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W1JKA
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« Reply #14 on: March 11, 2013, 08:47:56 AM »

 Specs are interesting and sometimes even useful,but as for me I pay very little attention to them since I only purchase on the basis of of borrowing or going to an others shack and actually trying out  whatever I am interested in to see if it meets my expectations.Obviously this is not the most expedient way if you are in a hurry to spend your money or do not care to wait until a unit is locally available or meet someone on the air that has one and you can reasonably connect with.
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