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In message <[email protected]>, Steve Bunting M0BPQ <steve@...> writes

Hi everyone,

I have owned my FT847 for a very long time, maybe 20 years. It is a UK
version that has usually worked on 70Mhz, but has stopped putting any
power out recently. The radio goes into TX on 4m, but does not put any
power out (measured on a Bird meter so there may be mW.). The radio has
the L5006 mod from? worked fine for
10 years or more.

The radio works fine on 50MHz so I know the PA stages are not kaput. I
have done a factory reset several times and do not know what to look at
next. Can anyone give me any clues?

Thanks
Steve, M0BPQ

I assume it works on Rx.

Someone posted a decent set of schematics recently. On page 6/7 you can see a section where the HF path splits to 3 different filters . One section is 54 to 76MHz. See if the signal is getting through that. Check the two steering diodes 3015 and 3031 and if the control voltage is functioning at the junction of R3041 and R3046.

I've studied the circuits at great length as I'm trying to find out why mine isn't working on 21MHz ( works everywhere else) . I think mine is that the relevant band pass filter in the PA isn't switching in as it doesn't work on RX either. Sometime I'll get round to debugging it.

Good luck

Brian GM4DIJ
--
Brian Howie