Re: in-band-IMD test

Posted by Barry N1EU on Nov 12, 2008; 10:38pm
URL: http://elecraft.85.s1.nabble.com/in-band-IMD-test-tp1491448p1491878.html

Alexander Ponomarenko-5 wrote

all these measurements, for all radios has been via PHONE-OUT.
There is two-tone measurements, but you can see these IMD even with XG1
set to s9-level.
Here is my K3 with s9-signal from XG1:
- ATT On http://forum.cqham.ru/download.php?id=32030
- ATT/PRE Off http://forum.cqham.ru/download.php?id=32031
- PRE On (it's terrible)  http://forum.cqham.ru/download.php?id=32032

Please take two consecutive spectrum readings with PRE On, AGC Off from the headphone jack - take one with S9 signal from XG1 and take the second with the XG1 generator turned off (i.e., with no signal in the passband).  Please post these two spectra.

I suspect many of the spikes in your spectrum reading are not related to the received signal.

Thanks,
Barry N1EU