Got a single/two tone audio generator in from Pacific Antenna yesterday.? Took about 1.5 hours to build it and check it out.? Made up a cable to go to the microphone input on the uBITX and set the spectrum analyzer up as close to what I was told when I asked Allison for the parameters.
the 16 MHz spur is there and still out of spec by a little.
I had a little less than 50 millivolts Peak to Peak audio at 1 KHz input to the mic jack, 2.6 watts output power (adjusted audio to jus below where output stopped increasing and backed it off until it dropped about 1 dB.
First picture is baseline trace with no signal being transmitted and the 2nd is the actual measurement.
Test frequency was 28.400 MHz.? 2 spurs, 1 at 16.64, 1 at 17.34 and a third spike not too far below the 28.4 carrier frequency that I ignored for this test as I don't know what it is caused by.
I'm primarily a CW operator so when it comes to SSB measurements, I'm a complete novice.? I did do the same check using CW on the same frequency and there were no spurs I could find.
If anyone wants further SSB testing, they will have to do it themselves as I need the spectrum analyzer for a completely other project and a totally different test setup.
Jim Sheldon, W0EB
TSW Project Coordinator
Jim Sheldon