WB0ZJJ-Alan via groups.io wrote:
I managed to build my QMX successfully, and in
two days of playing with it fried the receive
function. W1NC Jeff Moore diagnosed and
returned the radio to full function:
[Quoting W1NC e-mail:]
IC402 was destroyed. I used to see this
frequently in Rev 2 QMXs. But this is a first
for a rev 4 unit. It's hard to say why this
happened. Usually it is from back EMF when
switching from TX to RX mode. But there is a
protection diode in place for that after Rev 2.
For those of us who have early QMX units with Rev 1 or Rev 2 circuit boards, is it wise to modify the board to install the protection diode that is now included on current Rev boards?
