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@contesting.com> on behalf of Peter Bertini
<radioconnection@gmail.com>
Sent: 20 May 2019 20:40
To: amps@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@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|