Les
Crack the top case off, check the solder joint of the centre of the small piece of coax between the pcb and rear case mounted bnc socket. I have over the years found 3 whereby it was not soldered properly. This resulted in intermittent rx and crackling.

Go to the other end where its on the pcb, check the silver braid is either soldered or firmly crimped down too.

There was also a small batch that they had to solder a piece tinned wire from the bnc through to the joint with the coax centre because they had used the wrong sized crimp at the external pin centre hole of the female bulkhead mounted socket.

Mike de gm7bnf@...