Re: #QDX V3 filters and low output power #qdx


Alan G4ZFQ
 

Your RF sweeps look very different to the ones I posted for my 12v v3 QDX… https://groups.io/g/QRPLabs/message/87810 <https://groups.io/g/QRPLabs/message/87810>
Jim,

I read most posts, I see large variations on different sweeps posted from various QDX rigs.
I'm beginning to think the actual figures are meaningless although the relative values might make sense.

None of the traces is necessarily relevant to transmit power. They essentially check the RX BPFs although the test signal does go through the LPFs.
Esa says RX is good on all bands so we can assume the LPFs are at least passing signals on RX.
4 watts is acceptable, low power on 20/30m would indicate a problem with the LPF or it's TX switching.

I suggest careful examination of the 30/20m LPF soldering and components. Also check the LPF switching voltages conform with the description in the manual.

73 Alan G4ZFQ

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