[Amps] Measuring IMD in a home workshop

[Conrad PA5Y]

Hello Peter the best way of generating a clean 100W - 2 tone test is to use an ANAN SDR equipped with Pure signal. PowerSDR mRX has a 2 tone test built in. Then if you have a good SA just use that. As an alternative to a SA a Perseus SDR with an appropriate attenuator will allow you to do a good job.


The alternative is to build a couple of good signal sources or use 2 good signal generators with isolators and a class A amplifier that can achieve better than -50dBc on 3rd orders. This is quite difficult hence my suggestion of using an ANAN with Pure Signal active.


73


Conrad PA5Y


________________________________
From: Amps <amps-bounces at contesting.com> on behalf of Peter Bertini <radioconnection at gmail.com>
Sent: 20 May 2019 20:40
To: amps at contesting.com
Subject: [Amps] Measuring IMD in a home workshop

I'm wondering what techniques others are using to make IMD tests for
external RF power amps using test gear that would be commonly found in a
home workshop.

Spectrum Analyzers are cheap enough--I have several vintage HP 141T
analyzers set up, and a very capable Tek 497P with 100/10 Hz RBW.

My problem regarding two or three tone tests is that my rigs all have
comparably terrible IMD.  Several Ten Tec rigs, and a JRC NSD-515.  None of
them have spectacular IMD performance. How do you get around these
limitations?
_______________________________________________
Amps mailing list
Amps at contesting.com
http://lists.contesting.com/mailman/listinfo/amps