my QDX crashed after 25 QSOs on 40m and 30m. I changed to 20m. 5W power output. Voltage of the lead Battery about 13V . Than I smelled some smoke. No Power Output anymore an two melted BS170 Transistors. No Idea, what hapened.
I called a lot of CQ?s on 20m . About 10 times (15sec. TX 15 sec. RX). QDX was in the Case . Got to warm ?
Good SWR. I replaced all BD170 Transistors. fortunately I got 4 of them.
After replacing still no power. I can hear the Sigs with my TS940, I can receive all other Stations and at the output of allTransistors I get 40V with the RF probe (2x Voltage Peak of die Wave => about 4Watts). But no Sigs at the BNC connector anymore. Seams to be something destroyed between the P.a. and the low passes ? Any idea? I designed the QDX fpr 12V 3:2 Transformer.
73 de Matt, DL1SER
