26-07-2022, 03:51 PM
Reorganising my memories of the last 9 years as a form of relaxation therapy I remembered the GEC BC402 radios which caused me grief.
I acquired 2 of these 1959/1960 radios, not my usual requirement as I try to avoid ac/dc sets unless a bit special and these are a bit late for me.
Both were complete, one a little scratched about the white painted front. I had a friend who wanted a valve FM radio for his father so I cleaned up and checked out the better one for him.
The usual capacitor replacements were made, a working set of valves fitted and it worked well on all wave bands. It was dispatched with son for father's birthday.
The other set was a bit more challenging. Part of the mains dropper resistor was open circuit and a large ceramic tube resistor had been hung on the wiring beneath the chassis. I figured that this would be better above the chassis as it would get more cooling air flow.
There were a few nasty previous repairs to be put right and the "twiddler" had been at the trimmers and coil cores. A full realignment sorted it however and it worked fine.
The chassis was put back in the cabinet, back refitted with new screws as the originals were missing and put on soak test on the bench.
Distracted by a 'phone call and a call of nature it was some time before I returned to find the set still working but blazing merrily!
Without panicking, pulling the mains plug out and using a CO2 extinguisher quelled the blaze but not before the set was well and truly ruined.
Inspection revelled that probably excess heat from the extra resistor due to a smoothing capacitor going short had melted the highly flammable plastic tuning scale until it had drooped down and come into contact with the resistor. The resultant flames had set fire to wiring and the Bakelite cabinet.
The stink of burning Bakelite took weeks to disappear and the fumes caused a film of rust to appear on any exposed metal and tools in the workshop. I don't know what harmful gasses the fumes contained but they could not have been healthy.
So one BC402 a total right off. And a lot of cleaning up it caused too.
The other radio returned some time later smashed to pieces, it had been dropped from a fair height. Another BC402 total right off!
I don't want to see another GEC BC402 ever, the only radio that has ever set on fire in the workshop.
I acquired 2 of these 1959/1960 radios, not my usual requirement as I try to avoid ac/dc sets unless a bit special and these are a bit late for me.
Both were complete, one a little scratched about the white painted front. I had a friend who wanted a valve FM radio for his father so I cleaned up and checked out the better one for him.
The usual capacitor replacements were made, a working set of valves fitted and it worked well on all wave bands. It was dispatched with son for father's birthday.
The other set was a bit more challenging. Part of the mains dropper resistor was open circuit and a large ceramic tube resistor had been hung on the wiring beneath the chassis. I figured that this would be better above the chassis as it would get more cooling air flow.
There were a few nasty previous repairs to be put right and the "twiddler" had been at the trimmers and coil cores. A full realignment sorted it however and it worked fine.
The chassis was put back in the cabinet, back refitted with new screws as the originals were missing and put on soak test on the bench.
Distracted by a 'phone call and a call of nature it was some time before I returned to find the set still working but blazing merrily!
Without panicking, pulling the mains plug out and using a CO2 extinguisher quelled the blaze but not before the set was well and truly ruined.
Inspection revelled that probably excess heat from the extra resistor due to a smoothing capacitor going short had melted the highly flammable plastic tuning scale until it had drooped down and come into contact with the resistor. The resultant flames had set fire to wiring and the Bakelite cabinet.
The stink of burning Bakelite took weeks to disappear and the fumes caused a film of rust to appear on any exposed metal and tools in the workshop. I don't know what harmful gasses the fumes contained but they could not have been healthy.
So one BC402 a total right off. And a lot of cleaning up it caused too.
The other radio returned some time later smashed to pieces, it had been dropped from a fair height. Another BC402 total right off!
I don't want to see another GEC BC402 ever, the only radio that has ever set on fire in the workshop.
Boater Sam.