[Elecraft] OT: Amplifier's close in IMD product test

[Don Wilhelm]

Ken,

In my understanding, the "close-in IMD" is only applied to receivers.  The
ARRL Handbook describes the setup in the Test Procedures chapter under
Receiver Performance Tests - although they only desribe the 20 kHz setup,
the 5 kHz setup should be the same, but the frequencies will be closer.  2
signal generators, a Hybrid combiner, attenuators, the receiver under test,
and an audio voltmeter are the tools used.

Amplifier and Transmitter IMD is different, and the output is measured while
being driven with a 2 tone generator - 900 Hz and 1900 Hz are typical tones.
The output is most easily monitored and analyzed with a Spectrum Analyzer.
The ARRL Lab uses the setup shown in Figure 25.84 of the ARRL 2005 Handbook.

73,
Don W3FPR

> -----Original Message-----
>
>
> Does anyone know how to test an amplifier, or for that matter a
> transceiver,
> for close
> in IMD products? What kind of equipment is needed?
>
> Ken KG0WX
> K2 #4913, XG2
>
>