~~~~~~~~~~~ Continuation of above posting ~~~~~~~~~~~
8 ) Except for adding a 1.0khz wide (narrow) IF filter, and making a couple minor feature modifications
(configured the front panel “Carrier” control, to control max power in SSB mode as well as CW/AM, repurposed a front panel button for PA disable for easy-peasy transverter operation, etc.), my TR-7's are factory stock!
And, except for replacing S-meter light bulbs, and cleaning some internal contacts (one of my TR-7's spent time on-board an ocean-going sailboat, you know...), I've never needed to repair them!
Yep, you read that right....
they've never needed repair, at 43 years old, and they still hold their own against "modern" rigs!
{I did send my original TR-7 back to Drake (in the late 80's / early 90's?) for a few updates (they added an input protection and couple other minor changes, to make it a TR-7A) and an alignment, but no actual repair of either, and they still work great at ~ 43 - 44 years old....and I do use 'em, they're not "collector's items" up on a top shelf!}BUT..
But, I do need to do a re-alignment....

component aging and some internal adjustments are a bit "sensitive".
I get many unsolicited reports of "great audio" and "really clean signal".....and, hanging out with a few guys on 75m that run Apache ANAN's with pre-distortion, they commented that I have the cleanest "non-ANAN" signal they've seen! So, while I do need to do an alignment, and bring things back to new spec, my TR-7's are damn sweet!

9) About seven years ago (2013 / 2014), I started to think I might want a new HF rig (“just because”).....so, I started looking/researching again....and found (except for the classic MkV in Class A, or the pre-distortion equipped Apache ANAN's) none had a transmitter as clean as my TR-7....and I'm not interested in running a computer just to talk on the radio, so I just gave up...but, if I could find a reasonably-priced MkV, I still might just go for it...Class A, ya' know...
(but the Kenwood TS-590SG did look okay, and this past year someone recommended the TS-890S....and now, in 2021, Apache is debuting their "Andromeda", which is their "SDR with knobs", and that might be a contender, we’ll see?)
Of course, Rob doesn't even list transmit IMD…but, it is important to everyone on-the-air these days. (yes, some over-driving their amps, and/or running their mic gain too high, do contribute to the problem, but fact is many modern ham rigs are just crap in transmit spectral purity, and that’s when they are operated “properly”!)
And, coming back to this thread's actual subject
(rig choice and Rob's list) as I look at the new progression on Rob's list, I see that full SDR / direct-sampling rigs are being topped by modern "hybrids" (FTdx-101d) which are what we used-to call "IF-DSP rigs"!
It's just now these “IF-DSP rigs” have very-low-noise synthesizers, and are more traditional "down-convert" IF rigs (which have low HF first IF's, not VHF first IF's, and hence can have narrow first IF filters, what is now called a narrow "roofing filter"), rather than the IC-756ProII/III's, etc., that had wide VHF first IF's and noisy synth...
And, while I suspect DSP noise blanking / noise reduction is improving, having the noise / noise pulses reshaped and delayed by a narrow first IF filter, will make this difficult to be truly effective?
So, that's where I'm at...
That's my history and choices....~ 45 - 50 some years of HF rig use / choice....the reasons and results.
And, I’m still running ~ 43 - 44 year old HF rigs! ‘Cuz I just can’t find ones that are “better”, unless I could spend $5k - $10k (definitely
not going to happen), and/or want to operate a computer just to talk on the radio (not likely, here)
10) Finally, while I wrote up top that I wouldn't ramble on about Transmit IMD here, since that is my personal #1 criteria for "rig choice", maybe I should post some 2-tone test scans, and a few sentences about why/how this has become such an issue?
In addition to my recent (March 2021) scans of my 43-44 year old (and in need of alignment) Drake TR-7, I will include five scans for comparison here (and one clarifying white-noise vs. 2-tone testing, using an IC-781), courtesy of NC0B, Rob Sherwood, himself....saved from a couple of his presentations in the past 10 years or so:
a) a Collins 32S-3 (at ~ 100 watts PEP);
b) a Yaesu FT-1000 MkV, in Class A (w/o any ALC action) at ~ 75 watts PEP;
c) an Elecraft K3 (at 75 watts PEP);
d) one “double scan”, showing a “classic” IC-756ProII versus a “modern” IC-7600;
e) another “double scan”, showing a FTdx-5000 in Class A comparing it with NO ALC, versus ½-scale ALC;
f) 2-tone vs. White Noise, using an IC-781;
Fyi, my TR-7 has about the same IMD responses from 5-10watts PEP, up to 125-130watts PEP....some products are lower a db or so, and some are higher by a db, throughout this whole range of power output....although at 150-160 watts PEP out, IMD goes up 2db from the figure at 125-130 watts. And, since I drive an Alpha 78 (or an Alpha 77Sx) with my TR-7's, I have the TR-7’s set to have a max output of ~ 60 - 65 watts across the whole HF spectrum....and, since I also wanted to test the final IMD (of the combined TR-7 and Alpha 78) at 1500 - 1600 watts out, I decided to do the TR-7 tests at my normal drive level of about 60 watts (~ +48dbm)...I have a Coaxial Dynamics tap connected on the side of my Bird 43, set at -68db (at 3.65mhz), so max output into my analyzer from the TR-7 is ~ -20dbm... (and ~ -6dbm from the Alpha 78). {BTW, also since the K3 was being operated at its "sweet spot" of 75 watts, as well as the MkV in Class A at 75 watts...I figured this would be acceptable to show as comparisons....but fyi, this is not a scientific transmitter comparison treatise, rather just a way of showing examples of what is out there, what is clean, and what isn't.

}
Fyi (especially for those who question the use/validity of two-tone-tests), look at human voice freqs, where normal or raised male voice freqs peak in the 400hz – 600hz range, and roll off below 200hz and above 1600hz, falling off steeply above 2000hz. And, “loud” male speech peaking about 650hz, but rolling off at the same rate and freqs. (female voices a few hundred hz higher)
So, using two (non-harmonically-related) tones, one low (600hz-800hz) / one high (1600hz – 2000hz), does actually approximate the mixing of various human voice freq, so while a “two-tone-test” isn’t perfect, it’s actually pretty good (see comparison of a two-tone vs. white noise scan of a Icom IC-781, courtesy of Rob Sherwood) and, you all do realize that it wasn't hams, nor ARRL, etc. that came up with these tests / freqs....it was old Ma Bell, RCA, Motorola, etc., etc., etc...way back decades before I was born.

[Of course, a static 2-tone-test typically does
not show the “buck-shot”/IMD caused by poor ALC systems, nor power supply issues, etc. but, it is the “standard” that we have.]


For marketing purposes (or maybe we should just say “for BS purposes”?), many brochures and adverts will spec an IMD3 number, but as you can see, with our normal speech freqs, typically the IMD3 product of our SSB transmitters falls either within our transmit passband, or darn close to it, on the passband skirt….so, it’s the 5th and 7th order products that are most responsible for adjacent-channel splatter, and the 7th, 9th and higher that are what presents as splatter beyond the immediately adjacent freq, 5khz to 10khz (or more!) up/down the band….but, many times a lot of hams don’t look at the higher order products.
So, to give a way to compare different rigs, just look at the width of the SSB signal at -60db from PEP, or even lower. (This is what is typically used in occupied bandwidth comparisons of various ham rigs, and by many giving seminars, such as Rob Sherwood, NC0B, etc...and as we see the 2-tone IMD products follow the curve of a white noise test pretty darn closely, so for our comparison purposes, we can make darn good comparisons!)
If you look at these scans, you'll see how nice and narrow that classic FT-1000 MkV in Class A is! (and, as long as you do not have any ALC action, it really
is that wonderful....even better than pre-distortion-enabled ANAN's, or an old Collins 32S-3, unfortunately you don’t hear many using Class A on these, as Yaesu didn’t design adequate cooling for this and some have called the MkV in Class A a “blast furnace”)....and you'll see the vintage tube Collins 32S-3, is super clean and its wideband / higher-order-products are wicked low....and you can see my old TR-7 (although needing an alignment) still makes a nice clean signal....but, opppss, you'll also see that K3 is wicked-wide and a rather poor choice for SSB operations (btw, the newer K3S is even a few db worse!)...
Now, to be clear, I’m not picking on the Elecraft, the Icom IC-7700 is just as bad! [It’s just that these rigs (Elecraft and the FTdx-101's, etc.) are not only commonly talked about as the “Holy Grail”, but are also the ones that Rob Sherwood uses as comparisons in his presentations, in regards to transmit IMD, and ALC issues...]
BTW, the IC-7600 isn’t too much better…and, if you’ve got any ALC indication (especially on any Yaesu radio), you’re probably pretty wide…and anyone running a rig in Class A, should not have any ALC at all, or they might as well give up on Class A operation, ‘cuz all it’s doing is heating your shack (but, if you set it up right, with NO ALC at all, you’re going to have the cleanest signal on the band!)
So, if you’re thinking of spending $1000’s of dollars for a new rig, you may wish to actually have a look to see how that rig might be polluting the air-waves, causing you and everyone else, troubles….and ironically, it’s these crappy transmitters that prevent most of us operating Phone (SSB) from even coming close to actually using the potential of the receivers in these rigs….
Sorta’ like we are all throwing money down the drain, buying radios with great receivers that we cannot use the potential of, because of the crappy transmitters inside, huh?SSB transmit width, at -60db below PEP:
FT-1000 MkV (in Class A) : ~ 3.2khz wide at – 60db PEP (and ~ 3.5khz wide at -60dbc), with IMD3 of -42dbc, and IMD5 at -70dbc (that’s IMD3 of -48dbPEP and IMD5 of -76dbPEP), and only 6khz wide at -80dbc – 86dbPEP…remember that’s in Class A, without any ALC action at all!
FTdx-5000 in Class A : ~5.5khz wide at – 60db PEP with NO ALC, and ~11khz wide at – 60db PEP with ALC at ½-scale.
32S-3 : ~ 11khz wide at -60db PEP (and ~13khz wide at -60dbc), with IMD(pep) numbers of -42 / -53 / -65 / -76
TR-7 : ~ 5.7khz wide at – 60db PEP (and ~ 13khz wide at -60dbc) with IMD(pep) numbers of -43 / -46 / -50 / -58
IC-756ProII : ~ 11.5khz wide at – 60db PEP versus the IC-7600: ~ 16khz wide at – 60db PEP
K3 : ~ 20khz wide at -60db PEP (and ~ 29khz wide at -60dbc), with IMD(pep) numbers of -33 / -40 / -48 / -50

Yes, I see the asymmetrical response in the scans of my old TR-7 (needs alignment)....but, if you actually look at the numbers and examine the transmitter width at down -60db(PEP) and down -60dbc (-66dbPEP), and compare that width to that of the old Collins 32S-3 (w/ 6146b's in the PA), and that of the "modern" Elecraft K3, the IC-7600, the classic IC-756ProII, the FTdx-5000 in various configurations of Class A, and even that of the "classic" FT-1000 MkV in Class A...I think you might be enlightened?
You can see how the 6146B PA, and the Class A SSPA’s (with NO ALC) have much lower wide-band / higher-order products…and how the crappy ALC of Yaesu (and others) seriously impact transmit IMD….and, in general, how crappy our transmitters have gotten….now, as I’ve said for years, with radios marketed with dozens of controls for the receiver and only two (power output, and mic gain) for transmit, and with few hams actually listening to their own signal OFF FREQUNECY,
no manufacturer cares how crappy their transmitters are….so, it is up to us, to care….and up to us to voice that concern with our wallets!What if NOBODY bought a new HF rig this year, that didn’t have excellent (or at least improved) transmit IMD…fyi, that would mean the ONLY HF ham rigs sold were ANAN’s….what would Icom, Kenwood, Yaesu, Flex, and Elecraft do? Maybe they’d get the message?
Hmmm….Maybe this is an idea worth thinking about??Ask yourself, who do you wish to operate a few Khz from? Or even 5 - 10khz from?
I know I'd rather it was a guy with a 32S-3, a TR-7, or a MkV in Class A, or an ANAN!
But, maybe some enjoy listening to splatter?
We
know the managers and executives at the radio manufacturers must love listening to splatter at home, ‘cuz that’s the radios they’re making / selling now-a-days, but what about the rest of you?
Do you all enjoy the splatter?
If not, how about stop buying new ham gear?
What if a few hundred thousand hams wrote letters (not emails, but real letters on paper) to Icom, Kenwood, Yaesu, Flex, and Elecraft, saying “I was going to spend $2000 (or $3000, or $4000, etc.) this year or next, on a new HF radio, but since you don’t make a radio with decent transmit spectral purity, I’m buying an older rig, or a commercial marine radio, or a rig that has a Class A PA, or an ANAN w/ pre-distortion, etc.”
Hmmm, what would they do, if NOBODY bought any more radios with crappy transmitters?
I suspect we’d have better PA’s in 6 months, radios with Class A PA’s in a year, and mass-produced rigs w/ pre-distortion in less than 2 years?
Maybe not, but I think it’s worth a try….what do you all think?
If you all think, it’s worth a shot, I’ll be the first to write my letters….let me know… 😊
11) So, to sum up….some might actually see how to use Sherwood’s List in choosing a rig?
And, certainly Frank has showed us that many hams are satisfied with their choices, especially those rigs that score high on his SPI (Sherwood Performance Index)…but, as I have been saying for many years
“few hams actually listen to/monitor their signal…and fewer still understand what their signal is doing 3-6khz (or 10khz) away”, so they might actually be “satisfied” with their rig, ‘cuz they don’t actually know what they are transmitting (and that is a sad fact).
In my opinion / in my experience, the short answer to that question is: Unless you’re a serious CW contester (especially a “big-gun”), the list is not the best way to choose a radio! And, please remember even serious CW contesters need a clean transmit signal (albeit IMD doesn’t play a role in a CW transmitter, rather it is CW keying rise-time/waveform, as well as transmit composite noise), so once they find some rigs with great narrow-spaced rec IMD, they should next be looking at its transmitter purity!!
Now, since most of us are not serious big-gun CW contester’s, “the list” isn’t nearly as important to the “average ham’s” rig choice, as some might think…I’m not arguing Frank’s statistical analysis (where some rigs that perform well on Rob’s list, do have high satisfaction scores), but merely stating a fact, that “the list” only shows specs/performance of half the radio…and reminding my fellow hams that the transmitter is the very important other half of the rig!! And, for SSB Voice (and digital modes that require linear operations), it is the crap from our transmitters (IMD / Splatter / non-linearities) that is the limiting factor in our receivers! (hence, why I keep saying that the transmitter is such an important part of our shacks…certainly more so than most folks think!)
The long answer is: everything I posted in this thread! 😊
That's my history and choices, over ~ 45 - 50 some years, of HF rig use / choice…the reasons and results....and I hope some find this helpful?
Fair winds and 73,
John, KA4WJA
P.S. I'm sure some will counter this with an argument regarding the "need" for a 60db S/N or S/I ratio on HF ham bands.....maybe saying this isn't like commercial users, etc....and sure that's all true...but how poor of S/N ratio do you desire to communicate with?
Anyone who has sat and listened to stations only 10 - 20db above the noise, or during summertime T-Storms here in Florida, when those static crashes can be S-9+30, knows that 30db S/N is good, 40db S/N is better....so maybe pick a number like 40db or 50db, and see what rig you can operate next to...and remember that this is all assuming the guy next to you is giving you the same signal strength as the guys on your freq...
Oh, and yes....I get it....some will also say that we hams move in too close to each other on the bands....and, if it's a weekday evening, no worries about moving apart....but on a cool winter's Saturday night? Or a contest weekend? Well, you're lucky if you find a spot 3khz wide!

{fyi, you're still gonna' want to be > 4khz above/below anyone with a K3, and that's if they're running barefoot at the sweet spot of 75 watts....and, oh baby, stay well away (6-10khz) from guys running FT-857/897''s FT-991's, etc.}