Finding the FT847 is drifting , got a kit to make it more stable .

 , it's a heater unit that fits on the crystal.

 

moved the LPF filter in the amp to the top for easy access after it was blowing caps

the FT847 is a bloody good LNA killer I've killer two LNA's , whats happening it puts out a hi power pulse on PTT , the then get to the output side of the LNA as ists switched in to receive, then it blows the saw filter.

Solution is two fold ,i could fit the inhibit mod on the atu. but best of all is to use separate TX and RX lines , there is easy access to the rx input inside the FT847 , so got it coming out on a n SMA connector to the LNA,   Now the RF path goes to the Amp only , on receive the LNA is switched in . I've  added a sequencer from VHF Design as the W6PQL sequencer give problems, it just enables the bias on TX and manages the temperature of the LDMOS devices now, it inhibits tx of the Heatsink get to warm.

luckily my FT847 had a SDR module , but no good for VHF, its HF only.