HF Transmitter #18 - Completed Build, More Testing! 

A lesson in testing a homebrew transmitter, thanks!

Nice work as usual. I'd offer that I think your audio might be missing some of the highs in your voice, at least that's what it sounded like to me and looked like on the SDR display as well. At QRP having a bit of punch would be helpful on SSB. Look forward to seeing the final rig up and running!

Interesting. Kudos.

Interesting testing.. What were the individual powers of the 2 tone tests. And the rated power of your Transmitter. I have analogue 2 tone generator as well. There are some internal audio harmonics. If you have a rf signal generator and a mixer you could look at products using a sound card as well. If you are using a bipolar PA it's possible that the bias is collapsing under RF drive. Check base bias voltages with a series 10k and 10nF to ground, to a DMM. I have seen UHF PAs actually go negative under moderate drive levels

A thought on confidence checking your test results apparently outperforming commercial gear on some parameters: it might be useful to perform the same tests with the same testgear on a commercial rig. - If you're still reading unreasonably good results then you know that you have a test setup problem. - If you really are doing better than commercial gear on the parameters in question, then you'll have an evidentiary basis for this. (The same applies with your subsequently-obtained TinySA or any future test equipment acquisitions. Getting results through your test setup that line up with the manufacturer's specifications provides improved confidence in your test equipment, fixtures, and procedures.)

👍 ❤

Part 97 of the FCC rules and regulations. It's online, and specifies transmitter harmonic content.Hams are obligated to know the rules.

as I said before , no code