Date sent: Sun, 16 Dec 2001 17:09:24 -0500
To: amps@contesting.com
From: Jerry Flanders <jflanders2@home.com>
Subject: [AMPS] Two-tone audio generator for testing IMD?
>
> Is software available for the PC sound card to generate two audio
> tones for doing some IMD tests on this 5CX3000A amp that is slowly
> taking shape here?
You can not, unless you have an exceptional exciter, dump two
audio tones in the audio and measure the amplifier.
If your exciter is 60 or more dB down for all IMD and spurious on
two-tone tests, then you can use it (provided the amp isn't
expected to be anywhere near that good).
You certainly can't measure the IMD on anything but a good
selective level meter or spectrum analyzer...looking at the audio of
a receiver is a total waste of time.
Keep in mind most two-tone tests can't show most IMD caused by
PS or grid voltage regulation problems.
73, Tom W8JI
W8JI@contesting.com
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