Hi
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I built a QMX mid-band, it started up first time and everything seemed pretty normal except for low power output.
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tx into a dummy load with a 11.9v supply:
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60m 9.5v(red) 1.7w 1.04swr
40m 9.5v ? ? ?2.4w 1.05swr
30m 9.5v ? ? ?2.4w 1.05swr
20m 9.5v ? ? ?1.8w 1.10swr
17m 9.5v ? ? ?1.5w 1.14swr
15m 9.6v ? ? ?1.3w 1.2swr
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Thinking the RF out was low, and seeing the low voltage on the transmit diagnostics, I looked at the 4 output transistors, without the washer heatsink. After a few of seconds of tx, 3 transistors were hot to the touch, and one was cool (Q504). I visually checked again for problems around the PA, nothing visible. I was attempting to measure the ground to gate voltage, my hand slipped and the DMM probe shorted something near the PA, my (non-current-limited PSU) made a nice high-current humming sound and now QMX won't switch on, no terminal on USB, nothing.?
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I'm hoping that all I've done is cook one or both SMPSUs? or will it be worse than that?
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I'm seeing 12.06v in and 11.30v at the pins of one SMPSU board but nothing else.
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Any tips or pointers would be appreciated. Hopefully its not just"buy a current limited psu and a new kit".?
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Cheers
Dan G7NNZ
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