Hacker RP18 Sovereign.

[Yorkie]

The QT button doesn't latch. It reduces the gain of the FM IF amp (and disables the AFC) so that you can find the centre peak.

Have you an audio oscillator so you can inject a signal at the top of the volume control?

Pay attention at the back please

See Joe's comments in post #1 re injecting a signal into the volume control.

I suppose the natural thing is to assume (often correctly) that it's the infamous AFxxx 'whisker' problem, but it complicates things not being able to get to the screens to snip them off - always worth a try. Even NOS AFxxx when they turn up are no better - it's an age thing rather than whether they're used or not. How ironic that when transistors first hit the market they were thought to herald a new dawn in which - unlike valves, it was said - they'd be 'everlasting'.

Best of luck with it Joe - how you suffer for your art