Joe:
The power output of mine was OK for about 20 minutes, then dropped to zero. Repositioning the radio on its back suddenly restored a few watts of power out, suggesting a bad solder connection or fractured SMD
I have seen various reports of problems similar to what you report, discovered early in factory-made units. ?Some who have reported low power out have replaced SMDs (resistors apparently) in the driver section, leading me to believe thermal expansion of the board compromises a connection or a component. The problem with these reports is that they usually don't offer a diagnosis, so we don't know what the original problem was. ?Just the act of re-soldering a bad joint might have been the real fix. You could also have a bad MOSFET. ?You'd lose half of the push-pull output. ?Or, it could be the drive pot has failed. ?Or a transistor in the driver. Or a software/RiPi issue. Unfortunately, lots of things could lead to your symptom.
If it's a new unit, you shouldn't need to be repairing it.
My advice would be to contact the makers. This forum has a few similar reports of low output power, and I'm hearing of others. ?If there's a quality control issue in manufacture, I think they should know of it so it (and your radio) can be fixed. ?
Jim
WB0KWJ
