05-05-2014, 08:06 PM
Any capacitor that connects the anode of one stage to the control grid of the next stage, some types are more vulnerable than others, especially wax types or old Hunts types.
In most domestic radios it's the capacitor that connects the control grid of the audio output valve to the anode of the preceding stage, if this capacitor develops a leak it will put a +ve DC voltage on the control grid, that can result in the output valve drawing to much current, this can result in the valves anode glowing red and the audio output transformer to pass more current than it's designed to and can often result in the transformers failure amongst other things.
I would change it on sight, even the more reliable makes of capacitors in old radios are getting past their best, old tubular ceramic and mica capacitors are more reliable but not always 100% due to their age.
Lawrence.
In most domestic radios it's the capacitor that connects the control grid of the audio output valve to the anode of the preceding stage, if this capacitor develops a leak it will put a +ve DC voltage on the control grid, that can result in the output valve drawing to much current, this can result in the valves anode glowing red and the audio output transformer to pass more current than it's designed to and can often result in the transformers failure amongst other things.
I would change it on sight, even the more reliable makes of capacitors in old radios are getting past their best, old tubular ceramic and mica capacitors are more reliable but not always 100% due to their age.
Lawrence.
