I could replicate your and other people's report of excessive current draw after the mod. The news is not good.
1. Q10 gate remains high on RX
?For whatever reason, the Q10 gate wasnt low. The reasons could be many, from the wire to pin 36 being disconnected to not having the updated software that operates the TX_POWER line.?
2. The PA gets powered up while in RX
The K9 relay is still in RX position, coupling the PA output to U3 input.
3. Oscillations set in.
There is a feedback loop in swing and the oscillations build up. Drawing high current.
4. The RF blows up the bias resistors (as shown in the picture). If you continue to keep the radio switched on (as I did), eventually even the U3 blows up.
I am working on full replacment of the T/R signal path replacment. Give me another 48 hours to sort this out.
On Thu, Oct 6, 2022, 3:00 AM ajparent1/kb1gmx <kb1gmx@...> wrote:
Fine work?
I'm approaching 70 and I do a lot of SMT, its a thing for me. Doesn't hurt I was trained by a watch maker how to do fine work like fix that pesky coil sping in neter movements.
I suspect when you wer adding the wire somehow you induced a voltage or had power applied between top with digital board and? main board.? Only takes maybe 20V to kill the gate of a MOSFET.
Right now I'm doing fine carving on mine.? Adding a 78l05 before the ASM1117 on the main board and next will be the digital board. Then I can tackle the T/R switching as that will need a board? to handle the diode switching.? So right now I'd describe the state of mine as "incomplete kit of parts some missing".? ?;-)
Allison ------------------ Please use the forum, offline and private will go to bit bucket.
