There is lots of older lab grade HP test equipment on the surplus market.
You dont need a SA that goes way into the GHz range to do an HF amp.
I started with a 141T system in 97 and upgraded twice as deals came along.
Many still use the 141T but it helps to be handy replacing discrete
components such as electrolytics, out of tolerance resistors and an
occassional piece of SS (no IC's) mostly in the PS and monitor sections.
A couple of legacy audio oscillators, a directional coupler slug for the
Bird and a couple of inline attenuators and youre ready to go. Some new rigs
even have the tone circuitry built in.
Thats the basic test and you have to start with knowing the IMD of the xcvr
even if just doing a system test. I use a TS-830 with a measured -42 dB IM3
and that wont corrupt the amp reading as would something at -28 or so.
Carl
KM1H
Carl
KM1H
----- Original Message -----
From: <Gudguyham@aol.com>
To: <dezrat1242@yahoo.com>; <amps@contesting.com>
Sent: Wednesday, August 01, 2012 4:19 PM
Subject: Re: [Amps] IMD test question
> Bill, I'm SURE with today's multitude of hams with SDR radios, you should
> easily get dozens of hams to give you "on the air" results. It seems
> there
> is a lot of IMD cops out there. Pick one.
>
>
> In a message dated 8/1/2012 4:15:26 P.M. Eastern Daylight Time,
> dezrat1242@yahoo.com writes:
>
> Is there a way for a homebrewer to accurately measure IMD without
> expensive
> equipment? I'm thinking of doing two-tones at full power into a dummy
> load
> while
> listening on a second RX nearby. How does one accurately analyze what one
> hears?
>
> 73, Bill W6WRT
>
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