Jonathan Fox - W0AMT
I finished the 222 transverter kit this past week and did some initial setup. Per the article on the NMVHF website by W7QQ and KK6MC I checked the gate bias and found it at 2.5 volts. I adjusted it up to 3.1. I did not have an opportunity to get an on-air report of the IMD improvement.
This past Wednesday I was able to make contact with NK5W on 222.110. However, I had some frequency stability issues. At first I was low by 2 MHz, after transmitting a few times I found I was 5 Mhz high. After ending the qso I went back to the assembly instructions and found that I had missed a detail. There are two mounting holes on the transverter board in addition to the mounting hole for the MOSFET. The instructions say to only use the #1 hole as using the #2 hole can cause oscillations. I missed that the first time. I am still using the #2 hole. I insulated the PC board from the metal mounting screw with a nylon washer.
I am hoping this change will improve my frequency stability issues. If not I will remove it completely and see what that does.
The WA5VJB 4 element cheap yagi I built for an antenna worked great for the QSO I had.
Is anyone available for a 222 qso this weekend? I would like to do another on-air check of the transverter.