Just built a U3S with relay board and QLG2. 7805 equivalent in TO220 case for 5V power. Was working perfectly for a few day's testing.?
then tx started cutting out a few seconds to half a minute after Tx. Turned out voltage was dropping to 4.90 (measured at input to main board) and processor was resetting. Current draw at this point was 280 mA. ?Non transmit current 140 mA. Power output with single BS170 was 200 mW. Processor never resets when in non transmit mode.?
I have touched up a number of the power solder joints (altho they looked fine before) with no change in behavior. Turning down the drive to BS170 to where output was only 100 mW allowed completion of transmissions.?
powering with known good 5V p/s directly did not solve the problem.?
Any idea where to go from here?
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73, Dan? NM3A
