NEVER? get? a hot air gun near these old circuit boards. These boards are very poor quality by modern standards and the tracks will be damaged very easily..
L101 is the low frequency RF tuned circuit, so is not the cause of the problem you describe. This tuned circuit is only used to peak the front end used from 500kcs through to around? 1800kcs.
Ideally, you would connect an oscilloscope to? TP109 and monitor? the waveform. This should rise and fall smoothly as the MCs control is adjusted through its range.
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