The lights are on, but nobody’s home

Yesterday I switched on my Collins KWM-380 as I often do. The lights and LEDs came on, the few short beeps emanated from the speaker, but no signals or S meter deflection. No tuning ‘blips’ as the main tuning knob is turned on the megahertz dial either.

The volume control gave an increase in hiss when turned clockwise and the numbers on the frequency display changed. I checked the aerial connection and found no problem…then I noticed…the dreaded smell of cat pee.

Now, since I don’t have a cat, the only other likely cause of the smell is a faulty smoothing capacitor. The KWM-380 is a heavy beastie, so it will have to wait a while until I have some space on the bench, and I have a ‘three shredded wheat’ morning.

If a smoothing capacitor has gone down, chances are there will be a fuse or other component open circuit too. All the main smoothing capacitors will of course, be replaced.