IMD Testing Flex 6400

Ed Johnson

Is it possible to do IMD two tone test using an audio file and DAX? I am looking to do this with a 2m transverter and a spectrum analyzer at several RF power levels

Doug Hall

Yes, I have used Audacity (a free Windows application) to generate a two-tone signal and send it to SmartSDR via DAX. Works well.
73,
Doug K4DSP

DH2ID

I use my Rohde&Schwarz HF signal generator and my spectrum analyzer using the methods mentioned here: www.ab4oj.com/sdr/flex/6700notes.pdf
The test results for my Flex 6500 are very similar.

Testing a VLF converter for SAQ Alexanderson (example)

Doug Hall

Alex, I believe you are talking about two-tone IMD3 dynamic range testing of the receiver. I believe Ed is referring to TX IMD testing which requires an audio signal generator, not an RF signal generator.

If I am wrong, please let me know.
73,
Doug K4DSP

P.S. The R&S test equipment is very nice. I did some work for R&S in Munich back in the 1990s. Bavaria is a lovely place.

Richard McClelland, AA5S

I lived by Ostbahnhof in Munich for eight years starting in the late 90s.  I always wondered what it was like to work at R&S, which is walking distance from there.

Ed Johnson

Doug,
Yes, I am talking about two tone Tx test for transmit IMD.
Thanks
Ed W2PH

DH2ID

Thank you for clarifying, that it's a transmit IMD test.  Good idea to use Audacity to try this. I've always used NF tone generators and will try an audio file now :-)
73, Alex - DH2ID