[Lowfer] " XR " WSPR beacon running the Class " D " PA - Working Good !!

[Andy - KU4XR]

Well, everything is running OK from what I can see here. I had to
tweak all the operating parameters. Sound card output, Mic gain
on the radio, and even the power supply voltage for the PA, then
adjusting the Variometer with each change. I finally have the
PA operating as it should. Driven on Hard, and off fast. T
The RF current is also very close to what it ran with the QRSS 
beacon setup. It's looking very good, and since I have routed a 
bunch of wires out of the trip zone, I may just let it run overnight.
The PA transistors are " Cool as a cucumber " So, from all indications,
I must have everything fairly well matched, allowing the higher output.
It won't move the S-meters any, but gone from 105 mA with the audio
amp PA, back up to 150 mA with the Class " D " PA. I never could find
the problem with the TDA7052AN Audio amp, and that sort of pushed me
to try the " already knew it worked " transistor amp, and sure enough
it paid off, and the beacon is back on. 


Andy - KU4XR - EM75xr - Friendsville, TN. USA

LOWfer Beacon " XR " 
 
Coordinates:  N:  35º 43' 54" - W:  84º 3' 16"