The "SDR" part of the Icom 7300 compared with Flex ?

  • 1
  • Question
  • Updated 3 years ago
  • (Edited)
I read the previous threads about an Icom 7300 verus Flex Signature series radios.  Most of the comments were subjective comments and some views on the ergonomics of the Icom. From a SDR design perspective (not knobs/lack of knobs, USB control, etc) how is the Icom compared to the technical specifications of a Flex 6000   (ADC sampling, etc) ??
Photo of Andrew O'Brien

Andrew O'Brien

  • 384 Posts
  • 44 Reply Likes

Posted 3 years ago

  • 1
Photo of Bob Craig, K8RC

Bob Craig, K8RC

  • 260 Posts
  • 104 Reply Likes
Well, you can start with the objective test results at Sherwood Engineering:

http://www.sherweng.com/table.html
Photo of Andrew O'Brien

Andrew O'Brien

  • 384 Posts
  • 44 Reply Likes
That table seems to produce basic performance data but does  not necessarily provide any information about SDR design differences. 
Photo of km9r.mike

km9r.mike

  • 425 Posts
  • 62 Reply Likes
the 6300's adc resolution / sampling rate is 16 bits / 122.88 Msps
Photo of Walt - KZ1F

Walt - KZ1F

  • 3040 Posts
  • 645 Reply Likes
And then you can take what Rob actually said. More hand wringing.
(Edited)
Photo of KY6LA - Howard

KY6LA - Howard, Elmer

  • 3762 Posts
  • 1621 Reply Likes
ADC: Linear Technology LTC2208-14. ADC driver: Linear Technology LTC6401. FPGA: Altera EP4CE55F2317N. DSP: TI TMS320C6745 (375-456 MHz, low power consumption). DAC: Intersil ISL5857IAZ.

ADC sampling rate: 124.033 megasamples/sec
Photo of KY6LA - Howard

KY6LA - Howard, Elmer

  • 3762 Posts
  • 1621 Reply Likes
Since DynamicRange is a direct function of number of sampling bits, the 14 Bit ADC explains why any Flex has a better Dynamic Range
Photo of Ken - NM9P

Ken - NM9P

  • 4239 Posts
  • 1351 Reply Likes
7300 vs flex...
14 bit ADC vs. 16 bit ADC - dynamic range and blocking dynamic range will be a little lower.

I have not seen any figures about phase noise in the oscillator for receiver or transmitter on the 7300. This will be potentially more important than many other parameters because it will determine real performance I. The presence of strong close signals. It will also determine how much it interferes with other nearby rigs.

The flex 6000 series phase noise performance is superb.

Implementation of shape factor on SSB and CW filters ... Skirts are much sharper on the flex. But using wider skirts allows the Icom to have a lower latency number. Flex currently gets the edge on selectivity. But this is software and can be changed by either manufacturer.

The flex 6000 series allows 2/4/8 channels of simultaneous digital (DAX) audio output to digi programs. I don't know how many the 7300 is capable of.

These and other characteristics will help inform a comparison.
Of course they are in different performance categories, but both are nice rigs.

Ken - NM9P
Photo of Lee

Lee, Elmer

  • 680 Posts
  • 287 Reply Likes
Official Response
I believe the 7300 is more like a SDR-1000 in terms of its design.  It direct converts to a baseband through the FPGA which then feeds a 36khz signal into a DSP chip where the "SDR" magic happens.  I think the chip is a version of Icom's off the shelf chip they have used since the Pro-3.  In the down conversion some video is split off from the FPGA and sent to a cell phone size touch display display.  The display has a maximum range of 1mhz or possibly 2mhz (the specs I read were not exactly clear)  The radio has 15 band pass filters so it is very different from the Flex.  IMHO all those filters were Icom's attempt to clean up ADC overload.  This design necessarily limits how much the "software" can be modified compared to the 6300 but the DSP is already pretty mature so I don't expect much modification to be happening anyway.  I don't think the FPGA has very much horsepower either.  

The 6300 picks up 7mhz of spectrum with it's more robust ADC and that is what is processed which is why you can view 7 mhz of bandwidth, and does not rely on any kind of BPF to pre-select the RF.  It's a very different kind of architecture with a more powerful ADC and FPGA as well as internal control processors which is why it can be a server and have he Flex API's etc.  The video is considerably superior in the information it conveys.  Like the 7300 the radio is primarily controlled through the display.  The 6300 is a considerably more complex and Flexible transceiver given the fact that it serves DAX and CAT as well as being able to connect to and tightly integrate with a multitude of third party programs.  For me the difference is like the difference between playing checkers and 3-D chess. 

73  W9OY
Photo of Bob - W7KWS -

Bob - W7KWS -

  • 322 Posts
  • 52 Reply Likes
Lee, How do you describe the Flex 6xxx FPGA & audio recovery arcitecture?
Photo of Lee

Lee, Elmer

  • 680 Posts
  • 287 Reply Likes
Bob I was trying to find the 6300's block diagram to look at that but I haven't been able to find it.  
Photo of Bob - W7KWS -

Bob - W7KWS -

  • 322 Posts
  • 52 Reply Likes
Lee,

It seems to me that comparing the 100% digital receiver of the Icom 7300 to the largely analog, digital-hybrid design of the SDR-1000, is somewhat misleading.  Or am I mistaking?

Like you, I don't have the benefit of a Flex 6xxx block diagram at hand but, for the receiver audio chain, I'll bet that the Flex and Icom differ very little in basic architecture.  Surly the Flex features higher end parts but I'll bet this extra horse power in the Flex is devoted mostly to its superb, extremely wide frequency video display and the other higher end features such as DAX, client/server, Etc.
(Edited)
Photo of Lee

Lee, Elmer

  • 680 Posts
  • 287 Reply Likes
I didn't say it was a SDR-1000.  Actually the KX3 has even more SDR-1000 character.  My point was the 7300 down converts to baseband "audio" before sending the down converted "audio" to a DSP chip for processing.   This architecture therefore was an obvious bow maximizing  cost containment rater than performance.  Cheap ADC, cheap FPGA, cheap screen, cheap DSP.  The architecture therefore limits the performance.  You can drop in a 16 bit ADC (there actually is a drop in 16bit version of the ADC used in the 7300, which is why I believe Icom cheaped out in its design) and use the same architecture and the performance of the radio will still be limited.  This is why a "next version" while for sure having more features will still be down the performance curve.  I don't recall the 6300 having any sort of DSP chip as a bottleneck.  As I recall the Flex takes full advantage of the versatility speed and bandwidth of the FPGA.

The OP asked about the difference that's the difference.

73  W9OY
(Edited)
Photo of Philip KA4KOE

Philip KA4KOE

  • 175 Posts
  • 22 Reply Likes
Has Bob Heil found his mind after losing it over the 7300?
:)
(Edited)
Photo of butch alline

butch alline

  • 38 Posts
  • 9 Reply Likes
What is this in reference to?  link?
Photo of km9r.mike

km9r.mike

  • 425 Posts
  • 62 Reply Likes
@ Phil

I saw a little of that and it was so over the top I could not even finish it.,
Photo of DrTeeth

DrTeeth

  • 1687 Posts
  • 389 Reply Likes
Coming from a medical background, rather than tech specs or design perspectives, one needs to have "double-blind" trials of rigs. It would be quite easy to set up so one would get real world results.
Photo of butch alline

butch alline

  • 38 Posts
  • 9 Reply Likes
++ double blind.  ++ real world.

One can compare specs on a Ferrari, Bently, Porsche, and Chevy Volt and still not come up with a clear cut choice.  You have to drive one, look in your wallet and then decide which one is for YOU.

 
Photo of Bill -VA3WTB

Bill -VA3WTB

  • 3888 Posts
  • 947 Reply Likes
But based on the specs and build of the Bently, I would think the Bently would be a nicer car to drive then the Shevy. And much higher performance. Without driving them...
(Edited)
Photo of DrTeeth

DrTeeth

  • 1687 Posts
  • 389 Reply Likes
Butch,

In my experience, one has to live with something before one can make a judgement. No matter how long one tries something out for, it is often not long enough. Yes, in that I also include XYLs! Nobody gets married without any other expectation that it will be for life - nearly 20 years and counting at this QTH.

Photo of Steve K9ZW

Steve K9ZW, Elmer

  • 1554 Posts
  • 768 Reply Likes
Consumer preference testing more often requires full product exposure. The use of the double-blind methodology seems less useful or common.

As for vehicles a lot depends on how you use them. As I trade at 75-90,000 miles my personal driver gets swapped every two-three years. Strictly a financial set of calculations.

"Fun cars" and motorcycles I turn over much slower.

Radios even slower yet. Some I never sell.

73

Steve K9ZW
Photo of Walt - KZ1F

Walt - KZ1F

  • 3040 Posts
  • 645 Reply Likes
Where the analogy to marriage breaks down is people continually change so the person you dated in highschool won't be the same person 10 yrs later. That radio will be, for all intents and purposes.
The whole dbl blind thing is simply college psychology and statistics. People have preconceived notions of what they like and prefer yet the results show, often times, is they act prefer something else entirely.

An interesting example of this is where my wife and I used to vacation in Jamaica. One of the games they play as they take newlywed husbands and wives and blindfold the husbands and the husband would have to pick out their wife by virtue of how their kiss was and it was amazing sad and funny how many got it wrong. That wasn't an example of double blind but I thought it was funny and kind of pertinent to this issue. And no, my wife and I didn't play those reindeer games.
(Edited)
Photo of DrTeeth

DrTeeth

  • 1687 Posts
  • 389 Reply Likes
@Walt
"The whole dbl blind thing is simply college psychology and statistics."

It is far more than that Walt. It rules out personal bias in the testing methodology (on both sides), which it is why it is used in the medical field.
Look at all those who say that Advil is really great but Ibuprofen never works for them. To save you looking them up, they are both the same thing, and exactly so.

It also deals with those non-scientific people who see a cause and effect when non exist. You know, the people who will not consider 'coincidence' when they think that some junk science garbage has 'worked' for them.

@ Steve
"Consumer preference testing more often requires full product exposure. The use of the double-blind methodology seems less useful or common".

When comparing the ride of a vehicle, a Ford fan will tend to prefer the rid of a Ford over a make that is disliked, whereby blindfolded, the reverse may be true. There is a LOT of unavoidable bias with full disclosure even though a double-blind test may not be practical.
(Edited)
Photo of Bill -VA3WTB

Bill -VA3WTB

  • 3888 Posts
  • 947 Reply Likes
How can you have a blind test? It would take hours to put both radios through all possible operating conditions.
Photo of DrTeeth

DrTeeth

  • 1687 Posts
  • 389 Reply Likes
Bill,

All possible operative conditions would not be required, just a broad enough example. It would certainly be much more valuable than the 'on-air' tests one sees in the ham mags

It would be MUCH more useful, even in a limited form, than reading the tech specs. 'Hours' is a small price to pay for such quantitative information.

As to how? One sends a library of inputs to a rig under various standardised 'propogation conditions' and there are hams listening to the outputs and the decide which they prefer and why. The listeners do not know the rigs under test and heither do the people having contact with the hams. The chat in the lab driving the rigs only communicates via lights, "ready?", "place headphones" etc.

I am sure I could do much better if I thought about the 'problem' for longer than I did to produce the above.
Photo of Walt - KZ1F

Walt - KZ1F

  • 3040 Posts
  • 645 Reply Likes
Sorry guy, I wasn't clear. NO, dbl blind testing is definitely more than college psych and stat. I said that as unless one took those particular subjects it would seem as garbledy gook. No, it is extremely important.

Bill, I believe I will be concurring with Guy on this but the test can be very straight forward. Forget the lab gear testing, which radio sounds better to the listener, not volume, clarity of signal, be it a distant weak signal or a complex high fidelity AM or ESSB. As an example I threw in the real life example. How many people would admit they couldn't differentiate their spouse from a woman they never met? Yet, may can't... in fact, based on that sample, most can't. It might well be random guess work. And that is where the statistics come in to see if a random correct guess or even incorrect guess is telling. My hypothesis is within the top 10-20 in the sherweng list, in fact based on the audible signal, one can't tell the difference between any two. On pre-knowledge a subject will choose that which is whatever they are predisposed to want, like picking their wife vs a complete stranger.
Photo of DrTeeth

DrTeeth

  • 1687 Posts
  • 389 Reply Likes
Got it now Walt.
Photo of Bill -VA3WTB

Bill -VA3WTB

  • 3888 Posts
  • 947 Reply Likes
Yes i see your point, but considering radios may have better performance on a condition vs another condition. Such as a crowded band with big signals, or a condition with very weak signals.
Photo of Steve K9ZW

Steve K9ZW, Elmer

  • 1554 Posts
  • 768 Reply Likes

In the consumer world Double Blind tests are disconnected from market acceptance.

You can through elaborate DB Testing do some qualitative comparison and a limited amount of subjected end user comparison, but all goes out the window when the branding and distinguishing product characteristics are unmasked.

 With ethical modifications DB Testing is of great use to separate pure performance from other biases in areas like the medical field, but ill applied in market acceptance studies.

Please remember that a great many of the radios out there have arrived at product development levels that "to the ear" are not readily different - they all exceed our limitations as testers. 

So it is the subject qualities - packaging, ease of use, displays, knobs-vs-no-knobs, remotability, price-point, brand-perception, ownership-emotives, product features, specific task features, and much more measures of difference, that are what we really make our purchase decision on.

DB Testing is an ineffective, inefficient and useless undertaking in comparing one consumer product to another in terms of total product packages.

If you only have a hammer, not everything is a nail.  There are more appropriate tools than the "hammer" of Double-Blind Testing to do product comparisons.

73

Steve K9ZW

Photo of DrTeeth

DrTeeth

  • 1687 Posts
  • 389 Reply Likes
@ Bill.

Those scenarios can be simulated and don't forget, you only have a list of tech specs at the moment to look at.

@ Steve

I am not suggesting that DB testing will supplant any other test nor should be the only thing considered when considering a purchase. Also, I am taking about testing and not the whole gamut of a purchase decision process.

Other than that, I would just like to say, politely, but strongly, that I disagree with your take on DB testing. Without breaking into a sweat, I can think of many things that DB testing will bring to the table where there is nothing at the moment.
Photo of Steve K9ZW

Steve K9ZW, Elmer

  • 1554 Posts
  • 768 Reply Likes

Let's agree to disagree.  Unless someone agrees it is a worthwhile investment to do a DB Test, we will never know.  If you'd like some easy-read information on product/marketplace testing strategies email me - good at QRZ.  (BTW I did an MBA in the UK, which was very interesting in doing market testing British-Style, which is a bit differently than in Germany or the USA.  Some of the differences have been reduced as the world has globalized & homogenized, but their remain differences.)

In many ways the lab work done by Sherwood and the ARRL is as close to a DB Test as you are going to ever see Guy. 

BTW spending some time with a IC-7300 was fun, but I don't have any plans to buy one.  I thought it was a neat unit, just the antithesis of where I am going with my "Modern Stations" that has the Flex-6700s in them. 

73

Steve K9ZW


Photo of Walt - KZ1F

Walt - KZ1F

  • 3040 Posts
  • 645 Reply Likes
Please remember that a great many of the radios out there have arrived at product development levels that "to the ear" are not readily different - they all exceed our limitations as testers. 
And that is pretty much the point here. I do, however, disagree, with your assessment on it's importance. It's used all the time in social sciences AS WELL as quantifiable sciences. But here we seem to be conflating opinions with science. And everyone is absolutely entitled to their opinion. Particularly in the case, discussed, ad nauseum, on here, much of the animus is over one opinion vs another from people that, given when most of us were young and crazy and went to one too many rock concerts or had the radio turned up consistently too loud, can't actually hear very well any more anyway.    But even if we were all in our 20's still, if you didn't know what it was, you couldn't tell what it was. So, by definition, that limits the testing to non-visual. Or so the hypothesis goes. This should absolutely not be considered as bashing at all as, if the results showed one, good hearing or not, absolutely could tell the difference, that is an equally important data point. My only point in dbl blind is that for anyone, wanting it so does not make it so.
Photo of Steve K9ZW

Steve K9ZW, Elmer

  • 1554 Posts
  • 768 Reply Likes

@Walt - agree.  As the "user experience" is neutered when the axis-of-differentiation that the user actually can make choice-decision on is marked to accomplish the Double-Blind Test what is gained through the test?  In my opinion the ROI (Return on Investment) for the exercise would be an insignificant predictor of marketplace performance in a peer radio instance. 

Since we cannot hear the difference for the most part, and would need to be kept hands off (imagining asking a control operator to activate/deactivate features/filters, so the test subjects were kept away from the bias of actual product contact, what would we learn?

Then knowing that the concealed product features are the actual axis-of-differentiation the buyer/owner uses, and that they can largely outweigh performance in many instances, would we even have a chance to learn anything useful?

Help me out, as I cannot see how to run a DB with any meaningful product with these parameters.

Thanks and 73

Steve K9ZW


Photo of Walt - KZ1F

Walt - KZ1F

  • 3040 Posts
  • 645 Reply Likes
How can I do this without coming under attack? OK, I think I have it. It goes to the ambient animus level on here with certain topics. As I've said before, I think there is great value in using any radio before one gets too far along in a purchase decision, regardless of the net result. I believe the value is ONLY practical in the deliberative stage of a purchase. Once you own one, as you said, it is sort of irrelevant unless someone has cycled back to the evaluation phase. So, in that regard it actually would be informative to know where one might reasonably expect there to be no definitive audible  difference vs the knee jerk of "of course you can". Case in point, let's take whatever thread it was with the guy doing an audible A:B between the 6300 and 7300. Frankly, as some of the youtube comments said, I couldn't tell, or more specifically, at time's I'd have said "oh clearly the 6300" and others "oh clearly the 7300". And we knew which one he was testing. So, the DB part is more as a definitive no preconceived expectation. Like an optometist, not entirely DB but, "can you see better now or...how about now".  In that case (s)he needs to know what the various strengths are and are trained not to verbally weight one over the other.

I think, for the most part, we're a technically savvy group. It would be nice to separate fact from marketing.

To some extent I say this only by way of a thought experiment but perhaps it requires another column in Rob's table. This could, in part, be satisfied with a line between the unimportant row and important row. If 'important' is being used as a synonym for discernible, yes, that should work. If not, then yes, it needs another line for discernible. Rob did reference this in another forum.
Photo of Ken - NM9P

Ken - NM9P

  • 4239 Posts
  • 1351 Reply Likes
While Double-Blind studies are great for testing soft drinks or medicines, I am not sure they would be practical or enlightening for amateur radio equipment or automobiles.  How would you do a double blind study of an auto without letting the subjects drive it?  and would you use the same steering wheel and brake pedals for each vehicle?  But they are part of the driving experience.....

The same, I think, is true between the Flex-6000 and the IC-7300 and other rigs.  The user interface is part of the driving experience.  The panadapter, the graphics, the control surfaces, or lack thereof, the ability to quickly make adjustments of critical receiving parameters to fine tune performance...these are all part of the "driving experience" of the various rigs. 

Indeed, unless the operator is given time to familiarize himself/herself with the controls and capabilities of the rigs, how can their ultimate performance be compared?

Howard made reference to this problem in one of his "shoot-out" articles.  The fly in the ointment in the comparison between the K3 and the Flex-6700 was that an "impartial 3rd party" adjusted each rig to the way HE thought each one sounded best.  But the problem was that the 3rd party wasn't perfectly familiar with all of the controls of both radios.  Therefore the "best" of each rig was not actually the "best" that an experienced operator would be able to achieve with either of the two rigs.  This reduced the effectiveness of the comparison. 

I have had a few people say... "But your rig will never sound like mine.."  My response, if I were more unkind, would be:    "Why would I want it to?"   [grin]

Ken - NM9P
Photo of Walt - KZ1F

Walt - KZ1F

  • 3040 Posts
  • 645 Reply Likes
I am not disputing there are other factors Ken. I do dispute the not applicable, of course it would be relevant. Perhaps a footnote by Rob that addresses each category and specifies the 'cohort' of other rigs any give value is in. People are reading WAY to much into the Sherwood list and there is currently no guidance on, within any category, what n rigs are identical, ergo the accusation one is 'worshipping at the alter of Sherwood" by cherry picking perhaps meaningless distinctions. Perhaps color code them.

I was addressing the singular column Rob sorts on and is the stick with which people on here beat up on icom/kenwood owners or prospects and perhaps K3S owners beat up on Kenwood owners although I've seen no evidence of that.

So being a fact based person I, speaking for all fact based people, would like to render the sherwood list ineffective as an evaluation tool as it exists today in its current form. Therefore a statistically meaningful test, not one conducted by people with a dog in the race. Think of it as the  food pyramid being financed by General Mills (eat lots of simple carbs every day).
(Edited)
Photo of Bill -VA3WTB

Bill -VA3WTB

  • 3888 Posts
  • 947 Reply Likes
All silly to me, I still think it boils down to likes and dislikes. to find out what radio is best, give me a break
Photo of Walt - KZ1F

Walt - KZ1F

  • 3040 Posts
  • 645 Reply Likes
OK Bill, I'll take the bait. "To find out which one is best, gimme a break". When did anyone say that? To say that, to you, it boils down to likes and dislikes. You should at some point realize that sort of blind faith doesn't work for everyone.
Photo of Bill -VA3WTB

Bill -VA3WTB

  • 3888 Posts
  • 947 Reply Likes
It just seems to me, that this is not like a taste test, deciding on a radio is really a complicated thing, some may buy only based on bench test, fools be them. Others, because it is big with a lot of dials, impressive.what ever it is. So I;m really asking, what would the d blind test do? End result?
Photo of Tim - W4TME

Tim - W4TME, Customer Experience Manager

  • 9186 Posts
  • 3550 Reply Likes
If you want to use both radios, buy a 6300 and 7300.  Use them for 30 days.  If you want to keep the 7300, we will refund you 100% of your purchase price.  You want to keep the 6300, we will refund you 90% of your invoice price of the 7300.
Photo of Walt - KZ1F

Walt - KZ1F

  • 3040 Posts
  • 645 Reply Likes
It removes some of the chaff. It differentiates relevant from irrelevant. As you said, "buys only based on bench tests...", precisely, yet so many people do and use it to beat up on others with erroneous interpretation of it. Tools can be great but not so much when they are misused.
Photo of Bill -VA3WTB

Bill -VA3WTB

  • 3888 Posts
  • 947 Reply Likes
Tim..what do you mean? all this hand writing as Walt would say is for nothing, what about all the testing that has been talked about,,,lol to funny
Photo of Tim - W4TME

Tim - W4TME, Customer Experience Manager

  • 9186 Posts
  • 3550 Reply Likes
Hand wringing, double blindness aside, we have de-risked the buying decision for those who are considering both the 6300 and the 7300. We would hate for someone to have buyer's remorse after choosing one radio over another.  It demonstrates we have confidence in our total SDR architecture and products.
Photo of DrTeeth

DrTeeth

  • 1687 Posts
  • 389 Reply Likes
@Tim
"If you want to use both radios, buy a 6300 and 7300.  Use them for 30 days.  If you want to keep the 7300, we will refund you 100% of your purchase price.  You want to keep the 6300, we will refund you 90% of your invoice price of the 7300".
Be careful, you do not mention anything about having to give one of the radios back ;-).
(Edited)
Photo of Ken ve7kwa

Ken ve7kwa

  • 103 Posts
  • 32 Reply Likes
<< If you want to use both radios, buy a 6300 and 7300.  Use them for 30 days.  If you want to keep the 7300, we will refund you 100% of your purchase price.  You want to keep the 6300, we will refund you 90% of your invoice price of the 7300. <<

Hmnn.. maybe some of the excess 7300's could be given away as contest prizes... First place gets a 7300 radio    Second place gets two 7300 radios... ;)     O.K.  O.K. people, it was a joke. I couldn't help myself... :)
Photo of Ken ve7kwa

Ken ve7kwa

  • 103 Posts
  • 32 Reply Likes
<< If you want to use both radios, buy a 6300 and 7300.  Use them for 30 days.  If you want to keep the 7300, we will refund you 100% of your purchase price.  You want to keep the 6300, we will refund you 90% of your invoice price of the 7300. <<

Hmnn.. maybe some of the excess 7300's could be given away as contest prizes... First place gets a 7300 radio    Second place gets two 7300 radios... ;)     O.K.  O.K. people, it was a joke. I couldn't help myself... :)
Photo of Barry N1EU

Barry N1EU

  • 495 Posts
  • 123 Reply Likes
I'm no DSP engineer, but the IC7300 directly samples RF down to a 36KHz baseband as opposed to the 0KHz baseband of Flex and they did this to allow them to use their existing dsp library.  Why is using a 36KHz baseband in and of itself an inherently inferior architecture?  

The one outstanding question about the IC7300 in my mind is the whole OVF, IP+, RF Gain implementation.
(Edited)
Photo of Charles - K5UA

Charles - K5UA

  • 319 Posts
  • 89 Reply Likes
Hi Barry,

Before the criticism starts over what I am about to write, let me state that I am very satisfied with my Flex 6500 and I think the Flex software engineers are going to really impress us in the next year or so.

Now to the point.  In all of the Icom 7300 vs. Flex 6000 series discussions I have read, I don't recall anyone mentioning how absolutely fantastic the 7300 transmit audio sounds. 

I have been involved with "hi-fi" ESSB audio ever since W2ONV started experimenting with the Focusrite Red series mic preamps in the 1990s.  I must admit I have never heard audio more open and pristine than the audio I have heard from the 15 or so 7300s I have heard on the air.  I have heard lots of wonderful ESSB audio over the years, but I am stunned by the transparency, fidelity, and lack of coloration of the audio coming out of these 7300s at a mere 2900hz bandwidth.

My point is this.....the 7300 may not hold a candle to the Flex 6000 series in every other aspect of radio performance, but the transmit audio is superb.  I am not saying that the Flex audio is not up to par, but there is nothing that I have ever heard, at any price point, that can compare with the transmit audio of the 7300.  My opinion, and my opinion only.  If anyone knows a way to slave a 7300 to a Flex 6500 so  that the 7300 would act as the transmitter, please let me know.
Photo of Ken - NM9P

Ken - NM9P

  • 4239 Posts
  • 1351 Reply Likes
I don't know that the 7300 is better than a properly adjusted Flex, but I will agree that in some of its standard profiles, the few 7300's I have heard on the air do sound very nice.  I heard Don - K7MX on the air a few days after he got a 7300 for testing.  He did some A/B demos and the 7300 sounded very good.  I still preferred the sound of his 6000 series...it was richer, and had better presence and fuller fidelity.  But he hadn't spent much time fine tuning it.  It was also on a standard 2.7 kHz kHz bandwidth with a "Rag Chew" profile.  So it was sort of apples & oranges.  The bottom line, though, was that I am sure the 7300 can be adjusted to sound very nice... as any proper SDR transmitter should be.

But then, it should be a simple matter to get a transmitter to sound good.  I am baffled that so many manufacturers don't seem to be able to master something that should ultimately be much simpler than mastering all the ins and outs of receiver design and all the DSP, NB, NR, Dynamic range, etc. involved in producing a fine receiver.

Other things I don't know about the 7300 are what a DX or Contesting profile would sound like, how the Compressor/Processor sounds, and how easy it is to program various profiles for different purposes.  I have become quite familiar with the PROC, TX EQ, TX filtering, and DEXP on the Flex 6000 and I like the way I can get it to sound in all of my various profiles.  I also like how easy it is to adjust and save new ones.

I currently have at least 12 different Mic profiles - 5 or 6 for my home station and main mic.  And about 6 more for various remote situations and different mics they use - i.e. the hands-free in my car, my Bluetooth headset when operating remote with my iPad, my wired headset at the office when using that computer and SSDR via the VPN, and my iPhone ear buds when playing around with the iPhone app....and I have both rag-chew and DX versions of each profile for each mic.  I haven't seen reference to anything that convenient in the 7300 literature.  Perhaps I have missed it.  But these are performance bonuses that add value to my 6000 experience. 

Granted that we are comparing only the first release of the 7300 firmware/software.  There are bound to be additional improvements. 

As I said before..."It sure is going to be interesting the next few years!"

Ken - NM9P
Photo of Charles - K5UA

Charles - K5UA

  • 319 Posts
  • 89 Reply Likes
Hi Ken,

I wasn't going to mention Don, K7MX, but he did an audio test between his 6500 and his 7300 using his self-described "$17 headset" mic.  After hearing the test, I told him the $17 headset sounded like a $17 headset on the Flex,  and it sounded like a studio mic on the 7300.  I'm sure Don will confirm this test that I had with him this weekend.  I did not know how to break the news to him, but he was not surprised since he had received similar reports earlier.

Like you Ken, I find it difficult to believe that there could be such dramatic transmit audio differences between such sophisticated radios.  It is remarkable to me that the 7300, which has only HI and LOW boost EQ controls,can sound better than any ESSB station I have ever heard. (There go all my ESSB friends).  I am just in awe of the 7300 transmit audio.  That is the only quality of the 7300 I am addressing, the transmit audio. The 7300 may indeed be flawed in many areas identified by other posters on this community, but transmit audio is NOT one of those areas.

I am a dyed-in-the wool 6500 user, but know fantastic audio when I hear it.

Ask Don run the test again for you Ken, the truth will set you free! (LOL)
Photo of km9r.mike

km9r.mike

  • 425 Posts
  • 62 Reply Likes
Hi Charles,

Not doubting what you heard but I came across a different situation with a different tester. The pr 781 on his 7300 sounded unimpressive and almost detracted from the semi legendary 781. It was as if the 7300 could not drive the mic properly but that could have been user settings, however an off brand hand mic he used sounded superior to the 781 ( huh ? ).

I also heard an average user of the 7300 in a round table and his audio was just that average. I have no doubt that you heard excellent audio but I do not think it is a result of plugging in the radio and turning on the power switch.

Seems to me that at a minimum the supplied icom hand mic would sound vastly superior to the $17 off the shelf studio quality sounding mic. Think about it.
(Edited)
Photo of Ken - NM9P

Ken - NM9P

  • 4239 Posts
  • 1351 Reply Likes
Charles & Mike,  your two anecdotes are exactly why I have been saying in this forum and in my tutorials that NO mike combination will be perfect, or sometimes even GOOD, with standard SDR settings.  They ALL require either major adjustment or minor fine tuning in order to match the mike to the voice and the purpose. 

The FLEX can sound good with many cheap mikes, but will never sound great. 
You cannot add with EQ and Processing what is missing from the beginning. 
But the difference between a $150 mike and a $600 mike is going to be lost on most people's ears, speakers, headphones, etc. though there are probably a small few who will be able to tell the difference.  But simply doing A/B comparisons between two mikes is not helpful because each mike will need to have its own custom setup - mic level, EQ, Filter width, PRPC, DEXP, etc. to bring out the best that each mic has to offer.

In the case of Don's $17 cheapo mike, it apparently matches one of the IC-7300's standard profiles nicely.  My guess is that if Don worked at it, he could probably get it to sound just as good on the 6000.......and the same for the 781 on the 7300.  It may be that Mike's friend was using the 781 with one of the 7300 standard profiles that was a poor match to it, either in gain or EQ.....My guess is that on both 6000 and IC-7300, one important key to good audio is the retraining of the operator behind the mike.  Almost all of these rigs with DSP Transmit generators can sound good.  Many of them sound extraordinary.  I personally prefer the way I have been able to adjust my Flex.  But that is for MY voice. I have no reason to bash the 7300 for transmit audio.  I am sure it can be made to sound great, too.  The receiver, panadapter, and digital audio transfer channels....I don't think they are in the same league as the 6000.  But for 1500, it is going to make a lot of hams happy.  If I had an extra $1500 I might buy one.......no....I think I would buy a Maestro for my 6500 first......so I need an extra $2800.  {grin}

BTW, Charles....I also play around with ESSB from time to time.  Unfortunately there are some ESSB stations I have heard that are simply WIDE, not Enhanced!  ha.  In fact, what some of them call "Great bass"  is simply a droning signal at about 100-125 Hz that is 20 dB above anything else in the signal and is so strong that I would swear that they had a carrier on their signal until I finished tuning it in.  The resulting bass droning sounds like one of those Mega-Stereo Subwoofer cars that you can hear a mile away as it comes down your street, and is so irritating that I am forced to resort to raising my filter low-end to about 150 Hz in order to filter it out!  (I am so very thankful for brickwall filtering on my 6500!)

Great bass, like processing,  can be and often is severely overdone. 
But that is the American way...."If a little is good, then a lot is better!"

Ken - NM9P
Photo of Charles - K5UA

Charles - K5UA

  • 319 Posts
  • 89 Reply Likes
Hi Mike,

I need to figure out how to route my RX audio to Adobe Audition so I can record these on-air audio tests, convert them to mp3s, and post them so everyone can hear what I heard in real time. I have heard on bad 7300, but it was way over compressed audio.  All the others I heard were truly the best audio I have heard at any bandwidth.  Stay tuned and hopefully I can get some good recordings.
 
Photo of Ken - NM9P

Ken - NM9P

  • 4239 Posts
  • 1351 Reply Likes
@Walt....several posts up the line...... At Dayton, Steve was presenting at the SDR forum that once a group of radios gets to the top tiers of MDS & Dynamic Range, that other factors, like Receive and Transmit Oscillator Phase Noise becomes more and more important, as are things such as filter shape, receive audio chain, noise abatement, future expandability, and Human & Digital Interfacing (my paraphrase).  

So, I agree that none of us should simply bow down at the altar of a single parameter on the Sherwood list.

There are a myriad of other factors that drive hams to their rig of choice.  My evaluation (biased as it may be) is that the 6000 series, even the 6300 is a superior rig to the 7300.  The question is "How much more superior?  In what ways?  and Does it matter to the average ham?  Is it enough more superior to be worth the extra cost?"  For many hams, the answer will steer them to the 7300.  Many others have particular needs and interests that will steer them to various models of the 6000 series ... or to other competitors.   The fact that the choices are multiplying is going to be good for all of us!  
Photo of Charles - K5UA

Charles - K5UA

  • 319 Posts
  • 89 Reply Likes
Ken,

I feel your pain about the hyper-base of some ESSB stations.  I prefer BSSB "Balanced Single Side Band".  I agree, that boom-boom-boom audio is not pleasant to listen to.
Photo of km9r.mike

km9r.mike

  • 425 Posts
  • 62 Reply Likes
@ Ken,

Yes the $17 dollar mic could have been a perfect match for his voice and the rig profile he was using and the icom hand mic could have produced a poorer result for his voice characteristics.

I  appreciate your explanations on this topic for I have learned from what you have provided. Before your and Howard's input on the topic of audio, I had almost zero understanding / appreciation about how an op's voice profile and the mic 's profile can result in different eq settings. Thank goodness for the panfall for w/o it I would be lost. Not only have I learned from you on how to use my panfall to set my transmit audio eq settings, I use it to affirm what I am hearing from other ops in diagnosing their audio quality. 

Another thing that you have not mentioned yet, but I think adds to the overall sound quality is an hf amplifier and if an op does not have an hf amp I have noticed that clarity goes a long way and will beat excessive compression / modulation any day.

Kinda along the same lines, I am trying to develop the habit of just using my normal conversation voice level and let radio setting provide the extra punch (ie contest profile) with emphasis on clarity.
Photo of Ken - NM9P

Ken - NM9P

  • 4239 Posts
  • 1351 Reply Likes
I isn't just ESSB stations, either., Charles. There are plenty of standard bandwidth who seem to think that all that extra bass they can get from their PR40 or RE27 gives them "ba**s." (terminology learned during my college radio broadcasting days.). But in reality, when overdone, it is a real pain in my neck....or a little lower.
(Edited)
Photo of km9r.mike

km9r.mike

  • 425 Posts
  • 62 Reply Likes
@ Charles

I believe that you have a good ear and a very good appreciation for great sounding audio. I was just emphasizing that I have heard some examples that lead me to believe that this was possibly more than just plugging in the radio and turning on the power switch.

The average audio example I commented on was heavy on highs and heavy on lows and nothing between. A great sounding audio in that specific group was a pro III but did not get the specifics if there was something else in his audio chain.
(Edited)
Photo of DrTeeth

DrTeeth

  • 1687 Posts
  • 389 Reply Likes
Sometimes I think that there is too much adjustment possible with the Flex. And this long thread is just about qualitative audio quality :-o.
(Edited)
Photo of Ken - NM9P

Ken - NM9P

  • 4239 Posts
  • 1351 Reply Likes
@Mike....amen. Penetrating clarity will almost always win over over-compressed, overdriven "loudness."

I am amused when I hear, and see on my pan, stations getting frustrated in a pileup and beginning to eat the mike and shout, thinking that it gives them an edge. I can see that they are spreading their signal out, wasting power in Distortion products, and their shouting up close is reducing clarity....they now have two factors, each actually reducing their chances in the pileup....

If you want to play sometime, use the full duplex trick I used in my videos and monitor yourself in the second receiver . While you are talking, take the 1K slider and run it up and down slowly to both extremes and see how it affects your signal. It is amazing the difference power & punch vs. clarity and natural sound you will see. The trick is to find the balance between the extremes. The "perfect spot" along the dial depends upon your purpose.

The same goes for the other sliders, though the 500, 1K, and 2K are the most dramatic.
Too much 1k makes you sound "honky" or horn-like. Too little lack power and clarity.
Too much 500Hz makes you sound like you are in a barrel, Too little makes you sound weak, and vowels are Indistinct and hard to understand.
Too much 2K makes you sound sharp and irritating, too little and consonants become indistinct and clarity suffers greatly.
Too much 4K makes you "hissy" and sound like you have a lisp or a whistle when you talk. Too little and you lack high end presence. Even though 4K is outside the usual 2.9kHz filter bandwidth, the lower end of the enhancement curve overlaps some of the range covered by the 2K control.
Too much 250Hz makes you boomy. Too little makes you sound thin and lacking in low end presence.
The 125 and 63 sliders add foundation in rag chew or ESSB modes, and can be important in finishing out a quality profile.

The trick is to listen with a quality set of headphones while adjusting these controls one at a time through their respective ranges until you really become familiar with what they each add or subtract from your audio profile. As you listen, and look at the pan display, you begin to get a real feel for it. For your own voice, anyway......

I am afraid that I have gone far afield from the OT, but perhaps not. The ability to adjust proper transmit profiles is a major part of the SDR functions of any modern rig.

Good luck, and have fun.

Ken - NM9P
(Edited)
Photo of Walt - KZ1F

Walt - KZ1F

  • 3040 Posts
  • 645 Reply Likes
So Tim chimed in with Flex's try it for free for 30 days against the 7300, buy both. I concur with Rudy's assessment on that, but hey.

No, I am not advocating people buy an ICOM or Kenwood or anything else. To distil this out for people is to use good arguments to make your case, not contrived ones that reflect poorly on the people that use them. How one markets a product, any product, counts, even if it's done by amateurs.

I own and use a 6500. There are many things I like about it. There are some I do not like about it. Some of those I've resolved. Requiring a computer to simply read the mail, I haven't and not sure I can but I did make a heart-felt suggestion about a product I felt will have tremendous traction, if only, with the non-contesters in the population of Amateur Radio Enthusiasts. I agree with Barry, someone is going to do that. I prefer it be Flex as I've made a rather large investment in SSDR.

If this is sounding like I am kinda wrapping up here, it is, as I am.
Photo of km9r.mike

km9r.mike

  • 425 Posts
  • 62 Reply Likes
@ Charles

Hi Charles. Just a quick follow up to back up your praise for the tx audio of the 7300. Please keep in mind that I have not had the rig on for the past 20 days due to work sched so I have not had the opportunity to hear yet what you have heard. I only had the opportunity to hear an early tester and an early user and they could of both had improper settings. Regardless, I initially did not hear anything remarkable.

 I was listening to some ssb this evening and heard two 7300's out of a total of four that had  imho audio that was probably in the top 10% of the best audio that I have heard before on the bands.  Both were using amps and both were no more than 100 mi away so signal strength was not an issue. Of the two one said he was just using the supplied hand mic and for a stock radio (plus amp) and it's supplied hand mike... wow. Easy better than average and like you previously noted borderline high fidelity and that was for the ( for lack of better terms) contest mode setting. It would easily be a signal that would stand out in a crowd in a good way.

The other op was in rag chew mode I presume. I did not hear what his audio chain was but I know it included a 7300 and that was rich, clear, good low end and borderline high fidelity as well. What was very noticeable as well for both was a very clean sounding audio. Just the op's voice with a dead silence for the background.

The other two 7300 were low in signal strength and were both at 100w. Their audio was not poor but it did not stand out in a good way either. BTW I have heard very clean very clear audio from radios who's signal strength were almost  at the noise floor and I am sure you have as well but those two examples were not like that. I am not certain why.

For the two stronger signals, just like you said very impressive and there is no doubt in my mind you have a far better understanding than I of what it takes to make that happen. Plus it sounds as if you may hang out now and then with the essb gurus which I have zero experience with.
Photo of km9r.mike

km9r.mike

  • 425 Posts
  • 62 Reply Likes
@ Ken

Yes sir and thank you for the additional help. In my previous post I was gonna point out that I have not attempted your full duplex technique yet but it is on the to do list. I tried listening on a separate receiver but I was not hearing finer adjustments so I concentrated on your panfall tips and received two very positive reports for two completely different settings 1. rag and 2. dx/contest . I was very pleased with the reports because in a way I was making settings w/o having any idea of how they actually sounded. I could only see the results, but following your advice I received two positive reviews. I will now try to fine tune both ( where applicable) with your full duplex technique and eq pointers.

Finally, I have never thought about it that way but indeed any distortion or excessive width outside of the tx bandwidth is simply wasted energy.
Photo of W7NGA

W7NGA

  • 449 Posts
  • 189 Reply Likes
Methinks if residual FM, phase noise, modulation index, and ultimate dynamic range is your main concern and focus in Ham Radio .. then sorry, you've missed the salient point (in my opinion) of being an amateur radio operator. Just to be clear .. I've seen more heart and soul in the guy with a DX60 and Hallicrafters SX101 .. trying to talk to his brother in Namiba on CW, than any of these soulless discussions of Sherwood rankings and the thrill of working Africa whilst sitting on the deck sipping a cool one with a Maestro in their lap, remote. Reality check ... just what do you want from amateur radio? At the end of the day .. what do you come away with that has enhanced your life experience in some positive way and afforded you a glimpse into the life of someone around the world? That's ham radio (for me) .. this thread, just noise. Sorry to be blunt. But I feel my 50 year obsession with this hobby slowly slipping away into the noise per discussions like this one  .. insipid, vacuous, sometimes inane.

I spent my weekend listening with my 6500, trying to find these stations in dire need of uber-clarity, 16-bit dynamic range, on the bleeding razors edge of competition and remote performance demands vis-a-vis Maestro and the ultimate Bluetooth connection .. and all I heard was San Diego, California, 599, TU. Next? That's ham radio? I did hear a SSB station on 17-meters from his hot tub ... with Maestro and a Martini in tow. S9+, California, QRZ? Geez ... 

W7NGA  dan
San Juan Island, Wa.
(Edited)
Photo of k3Tim

k3Tim

  • 924 Posts
  • 195 Reply Likes
Was it the Martini that threw you off? 
Photo of W7NGA

W7NGA

  • 449 Posts
  • 189 Reply Likes
Absolutely .. 17-meters deserves a fine French Bordeaux.  
Photo of Ken - NM9P

Ken - NM9P

  • 4239 Posts
  • 1351 Reply Likes
Dan. Who said that just because this is the current topic of discussion in THIS thread that it is anyone's main concern or focus in the hobby?

I am currently engaged in several concurrent conversations in this and other forums, some public, others private. None of them represent anything lose to an "ultimate concern" in my life. But they are, at least, temporarily interesting. Many of them are done while multitasking in my office or at home in my easy chair while watching tv or waiting for dinner. A few of them I only post to when I am in the "reading room" because it gives me something to do....

Sometimes sports car enthusiasts want to talk about cubic inch displacement, compression ratios, fuel mixtures, horsepower and transmission efficiency..... Sometimes they just want to drive their cars!

The same goes for amateur radio nuts. The fact that we sometimes spend time doing one thing doesn't mean we do not like to, or are incapable of doing the other.

Cheers!

Ken - NM9P
Photo of Ken

Ken

  • 17 Posts
  • 1 Reply Like

Dan,

I think there are more out here that think exactly like you do, but don't bother to say anything. I think it's called the "silent majority"...

Ken - W3KWL

Photo of km9r.mike

km9r.mike

  • 425 Posts
  • 62 Reply Likes
@ Dan

I hear your passion but one's passion does not make another's invalid, insipid, vacuous nor inane. What's next ? Are you gonna call others nerds ?

It is a big hobby with lots of room for lots of passions. I could easily take a swipe at your passions but it would not make me a better man.
(Edited)
Photo of Lewis Cheek

Lewis Cheek

  • 240 Posts
  • 41 Reply Likes
Dan, ur 599 plus about 40 on my xyz, antenna is  7 phased 5 elem 20 meter beams, on one of my 12, 350 ft towers. By the way, I'm on my 500 foot daysailer over in the Mediterranean Sea running remote via a Maestro. Wait a minute please I need to ask our house setter to drive over to my remote ham shack and fire up the other 10 kw amp, and parallel it with one I'm running now. Waiter when will the $5000 bottle of wine arrive?

Seems I read a lot of that kind of stuff on a few reflectors. :)

Lew - N4CO