Here’s three mysteries I can’t get my head round, and even had @G3CWI shrugging his shoulders.
When operating PSK or RTTY, it is really hard not to suffer RF feedback issues. I’ve only been able to reduce this either by winding a choke balun at the feedpoint, or adding a long extension to the feeder cable in order to have the interface well away from the antenna, including radials. With EXACTLY the same set-up, FT8 causes no problem at all. Why?
By having my FT-817 meter set to PW (power), I can see that after switch-on, power output on HF bands is very low. After a few minutes of operating (choice of mode makes no difference), the output power starts to creep up, and after 20-30 minutes, it’s getting towards full power. This is not the case on 50MHz and above, where full power is indicated from the off. Is this a finals issue? But they do work - eventually…
Both 1. and 2. above are noted on a variety of different antennas.
- I updated WSJT-X to the latest version today. Suddenly I now seem only able to decode incoming signals that are 200-700Hz below mine. Nothing has changed w.r.t. RX filtering into my set-up but I do note some mention of “bandpass” in the list of changes to this latest version - probably need to investigate!