[Elecraft] FW: Testing IMD3 (dB) K3S (#10490)

[K9MA]

Supply voltage, under load, at the radio?

73,
Scott K9MA


On 2/8/2020 16:14, Conrad PA5Y wrote:
> I have some comments.
>
> My TX IMD is even worse and I was not very happy with the advice I got from Elecraft.  I was advised to use the radio in test mode and use an external amplifier.
>
> Periodically I have a complain about it. My 10W PA is also poor even after the FW upgrade that allows additional attenuation to the drive. There are a few of us who discuss this off reflector and it is by no means uncommon.
>
> On a more positive note I must say that the transverter port output is exceptionally good. Its really impressive.
>
> As for the PA IMD, good luck, you will need it.
>
> Regards
>
> Conrad PA5Y
>
>
>
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> On Behalf Of hb9cvq at hispeed.ch
> Sent: 08 February 2020 01:00
> To: elecraft at mailman.qth.net
> Subject: [Elecraft] FW: Testing IMD3 (dB) K3S (#10490)
>
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> Subject: Testing IMD3 (dB) K3S (#10490)
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> Hi
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> Can anyone roughly confirm IMD3 K3S ?
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> 10W/100W module recently exchanged under Elecraft swap program Rev A (2019).
>
> Testing: Using K3S internal 2 Tone and -60dB power attenuator (50Ohms) , HP 8591E Spectrum Analyzer (Span 10kHz)
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> 72W (Tune, LP100A)out into 50Ohm:
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> IMD3 (#10490) -->about on 160m 34 dB, 80m 32dB, 40m 34 dB, 20m  26dB, 17m 30 dB, 10m 30dB, 6m 26dB
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> Yes, all was aligned (TX Gain test) and showing 100 to 90W full power on all bands.
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> The driving signal to 10W PA (one tone) looked better than 50dBc.
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> I think these IMD3 values are not very impressive. A power amp. would typically further degrade the overall results.
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> So K3S is rather good for CW but not really good as SSB preference? (I have now also a FTDX101MP)
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> Comparing with K3 (#7848) upgraded myself to "S", but still maintaining the old 10/100W modules.
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> 80m and 20m were better by about 6dB!?
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> The two tones (IMD3 Test Tones) however were in both cases never absolutely identical in amplitude (ca. +/-1dB) on the analyzer.
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> Any comments?
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> Tnx, Cu, vy 73 de Andy
>
> HB9CVQ, DK2VQ, AK4IG
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>   <https://www.qrz.com/db/HB9CVQ> https://www.qrz.com/db/HB9CVQ
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-- 
Scott  K9MA

k9ma at sdellington.us