Posted: 12/11/2014 10:24:52 PM EDT
[#14]
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I wish people on the net stop making comments on radios they never even played with, instead they look at some test results from some nerd that only operates CW.
Mr Sherwood never comments on such things like front end noise floor, AGC performance, DSP performance, Audio quality (both RX and TX), ergonomics etc. He instead concentrates on one thing forgetting everything else. His test data puts a KX3 in the same category as an FTDX5000.
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WOW.
That's the grail radio. That said, look where Sherwood rated the KX3 against the Hilberling.
Link to ratings?
I wish people on the net stop making comments on radios they never even played with, instead they look at some test results from some nerd that only operates CW.
Mr Sherwood never comments on such things like front end noise floor, AGC performance, DSP performance, Audio quality (both RX and TX), ergonomics etc. He instead concentrates on one thing forgetting everything else. His test data puts a KX3 in the same category as an FTDX5000.
Gyprat,
That's not the only thing Rob considers. Here's one recent example of his well rounded understanding of radios in a post on the Yahoo group about the TS-590 series. He makes many similar comments around the web about other radios and radios in general.
https://groups.yahoo.com/neo/groups/KenwoodTS-590/conversations/topics/24949
I don't know if you need to be a member of that group to see it so I'll quote him here.
Hi everyone. Let me comment on test data on my web site for the TS-590SG.
First there are new features, and I haven’t had any time to even look at them yet. I also haven’t yet used the SG on the air, but simply ran it through the lab yesterday afternoon in about four hours. I have a long form report available, but I cannot give any “user” feedback yet. I did run the original TS-590S in a 160 meter CW contest in either 2010 or 2011, doing a “shoot out” between it and the T-T Eagle. The Kenwood was easier to use, but both handled the QRM well.
All the radios in my web table have been ranked by one number, close-in (2 kHz) dynamic range. This is an important number, particularly on CW. It should not be considered the only important data point. That would be like choosing a sports car that had the biggest engine, but disregarding how it handled on curvy roads! Lots of aspects of a radio’s performance are important, and close-in dynamic range (DR3) is certainly one of them.
The dynamic range, and in this case the RMDR, is modestly better for the SG version compared to the S version. RMDR stands for “reciprocal mixing dynamic range” as per the ARRL definition. (April 2012 QST, sidebar Bob Allison Lab Engineer) I used to call this “phase noise limited”. It is the same thing. Since day one (1977) I always ranked my chart (table) as to how the measured dynamic range could be the performance limit in a CW pile-up (DX or contest).
Another thing that I feel is a problem when we are all in the search of “the holy grail” of receiver performance is the question of “what is good enough”. When I was visiting Flex Radio this year, Steve Hicks said he felt that he could draw a line at some point in my performance chart and say everything above that line “is good enough” from the standpoint of dynamic range (be it third-order dynamic range [DR3] or RMDR). I agree with that statement. So does Tom Rauch, W8JI. Tom and I have said for years that 80 dB is usually good enough. Since it would be rare to be able to operate a radio at its perfect optimum, maybe you want a bit higher number. In the past couple years, as radios have improved, I have said I want 85 dB or more. How about 90 dB so there is a bit of a safety factor.
For this one data point, the TS-590S came in at 88 dB for the down-conversion bands, and 76 dB for the up-conversion bands. The TS-590SG comes in at 92 dB for the down-conversion bands and 79 dB for the up-conversion bands. Kenwood has clearly said in their advertising material that the SG has a cleaner local oscillator (LO). The first mixer is also discussed, but I don’t know what might have changed there. The wide-spaced (20 kHz) DR3 of both units measured the same at 104 dB.
I don’t get excited about blocking numbers since they are 30 to 40 dB above DR3 (or RMDR) values. The League tests blocking with a 1-Hz audio spectrum analyzer so that phase noise is virtually eliminated from the measurement. It is a valid measurement for the design engineer since it tells him when to quit spending money on the mixer and when to focus on the synthesizer (LO). For the amateur I don’t think the 1-Hz number is a useful, since none of us use a 1-Hz CW filter on the air. Likewise the ARRL DR3 number since 2007 has also used this same phase noise elimination testing method. I briefly tested a few radios for blocking with their method, and my blocking numbers with an “S” footnote were done in that way. I later decided this was meaningless data, so I don’t measure with a 1-Hz filter anymore. Thus it looks like the 590S has a higher blocking value than the 590SG. That isn’t the case since the two radios were tested in different ways. I never tested DR3 with a 1-Hz filter since I always thought that measurement was misleading. If the RMDR of a radio is 80 dB, and the DR3 measured with a 1-Hz filter is 100 dB, the real limit of that radio is 80 dB. (Read the QST sidebar for a better understanding of this issue.)
For the last few months the TS-590S has been selling at a truly bargain price of about $1250. If a ham could only budget that much for a radio, I would recommend buying one of the few remaining TS-590S radios. If $1750 is in the budget, I would buy the new one. It is great that Kenwood continues to improve on a fine radio. It was a great radio when it came out four years ago, and it is even better today.
73, Rob Sherwood, NC0B
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