[dazzlevision]

After replacing the “tin whiskered” AC187 in the audio output stage, I thought I’d check and replace (as a matter of course), the elderly electrolytic capacitors present on the IF/audio PCB, of which there are several. Some are the classic blue sleeved Philips/Mullard type, there are a couple of the notorious black “Callins”, one “Sprague” WT metal cased axial and four orange “SWT” plastic cased radial types (I presume SWT = Sprague WT).

I found that one of the Sprague SWT radial types (C92, 200uF/10V) would register a reading of 2.5 Ohms on my DMM whilst it was part way through charging up! It decouples the zener diode stabilised 5V rail that supplies the RF and IF stages. So, worth checking the electrolytics.

After fitting replacements, I thought I’d check VR62, the 220 Ohm horizontal skeleton preset pot that sets the working point of the output stage. It measured 1000 Ohms, so I replaced it and readjusted.