A couple of weeks ago, I think, I brought up an issue I'd seen with my QMX low-band (20-80), where I was only getting about 1.2W out on 20 meters.
Today, I decided to run some tests using a new power meter and dummy load, and also to see if maybe I'd set a setting wrong.
The results were a little surprising, and probably point to some hardware fault, and not a setting problem. To double-check that theory, I did a factory reset and a firmware upgrade, and received the same results.
I have both narrated video of the power meter, and screen recordings of the terminal app, that I can edit together if they would be useful. I had been thinking of terms of posting a YouTube video about "fixing it" but then, of course, I was not able to fix it!
(That said, I may at some point do a YouTube video guided tour of the Terminal App!)
What I'm seeing when I hit the 'T' key in the Diagnostics screen:
Input voltage looks steady at 11.7
SMPS 3.3V shows 3.3V, 5V shows 5V, Bias SMPS shows 30mA as does PIN Bias
For all of these -- and this may be the hint -- the transmitter voltage shows 10.2 transmitting, 0.6 idle
80m: Diagnostics show 4.7W, power meter shows 2.0
60m: Diagnostics show 5W, power meter shows 3
40m: Diagnostics show 4.3W, power meter shows 2.5
30m: Diagnostics show 2.5W, power meter shows 1.25
20m: Diagnostics show 1.2-1.3W, power meter shows 0.5
Where is the most likely place to look for both the shortfall relative to the meter, and the shortfall relative to general expectations of 5W as opposed to 1.2?
Thanks!
Michael WD0OM
