开云体育

Hi all,

?Went to use my bitx-40 and found no RF power output, started by checking the voltages on the IRF510, drain voltage was there, next check voltage on gate, zilch, nothing, narda.

Next check voltage to 78L05 regulator, yes 12.5V, check output, no 5V, next visual of regulator, looks like solder has not taken on the input pin:-( Difficult to see without a magnifier.

Re-solder the input pin, the output of regulator is now 5V, transmitter output restored.

?Semiconductor devices are very reliable if their maximum limits are not exceeded, most problems are usually related to connections in one form or another.

I suspect the junction between the solder pad and regulator had oxidized making the classic dry joint.

Alf vk2yac