Elecraft Transverters
I decided to stop my tweaking and take some measurements in a slightly more scientific format. –aka… I was stumped and needed to noodle through my data and step away for a little bit.
- I went back to each transverter and reset the PA bias to 20mV.
- I did not adjust any of the filters… good or bad… measured As-Is
- I measured each transverter with three different R22 values Full Counter Clockwise, Centered, and Full Clockwise. (R22 is a variable attenuator for the IF input.)
The fields below that are yellow indicate that I don’t trust the results of my oscilloscope. (It is an old slow 60 MHz scope so I am pushing my luck measuring the LO and Mixed values on the 222 and 432 transverters.)
All oscope values are with the probe @ x10 - K2 drive from the K2 display
Good news: The 2m transverter (XV144) is working good. I am seeing what I expect for power levels and it should be near it’s final form.
Bad news: The 222 and 432 transverters need some help. I am not sure of the exact problem but I have two ideas to investigate:
1. Go back thru the filter adjustments. I think that I need more signal going into U6.
2. U6 – is it bad or not getting enough signal to do much real work?
73 de NG0R
PS… I need to go back to remeasure the power out of the XV144. I thought that I had a 50w slug in the bird 43… but I think that I actually had the 10w slug in there. –That will mean that my power is still pretty low but at least it is measurable. 
PPS… C53 in the bandpass filter was acting weird on the XV222. I found it while poking around with the oscope. I top soldered the joint and resolved that little issue.
PPPS… I tweaked up the power level on the XV222. It is still running less than QrpP levels. I am going to take a break for the evening and ponder this some more.
PPPPS… After some pondering and discussion with N0FP I think that I have a plan of next attack to diagnosis this issue. Notes to follow once I have time to revisit the work bench.
