Discussion in 'Radio Circuits, Repair & Performance' started by W8KER, Sep 20, 2020.
i have a pro 3 that transmit full power out put untill it warms up then drop to 10watts
Is the cooling fan running?
If so, is it running at high speed?
Could be a ALC or more likely a RF pa problem.
Yeah I got a fan on the back also sucking air out to help keep it run cool
I’m thinking ref pa problem sending it off to get look at might be a simple fix might not I get it fixed guess going buy 7300 to do Digital on use this for voice
Yeah, I also have a Pro III and it is still working fine; but, the day it dies -- I will be off looking for a new radio.
I can't complain about the Pro III because it just keeps on going. Icom has some really nice new radio's -- I just can't justify replacing a great working radio now that I am retired.
Anyway, good luck with your's. It is probably in the ALC or PA area; but, you probably already know that.
You might look at the PA drive level to see if it is falling off.
I’m like u pro 3 is a great radio mine one of the last ones they made just parts getting hard to find I heard and icom doesn’t want to work on them any more which is a shame
If the serial number is greater than 4500, you are in luck. Icom re-designed the PA board and used MOS FET finals. Component(s) on the PA board are most likely the culprit. If your serial is lower than 4500 - the Bi-Polar transistor finals and some other devices are un-obtainium...
OP, I suggest you join the 756 pro 3 group, https://groups.io/g/ic756pro3
You'll find threads on similar issues there along with sources for some of those hard to find parts .. Plus helpful advice