Cossor radio repair - UK Vintage Radio Repair and Restoration Discussion Forum

telstar · 28th Oct 2020, 2:33 pm

Hi. My brother was asked to repair an early Cossor 1930's radio recently which he managed to get working. However, it became intermittent and the cause of this became difficult to trace. Before this occurred he had to buy a replacement R.F valve from a supplier in Europe, and this turned out to be the fault. The heater wire inside the glass envelope had not been connected to the end of the terminal, but instead was left un-soldered inside. The supplier did not accept returns, and any way it was too late to return the faulty valve.
Has anyone else experienced similar events?
Cheers
Mike

60 oldjohn · 28th Oct 2020, 2:40 pm

Hi Mike, Sorry about the valve, are you able to take photo of the loose wire? then contact seller. What valve is it? worth asking on here if anyone has one to spare.

John.

Cobaltblue · 28th Oct 2020, 3:38 pm

Quote:

Originally Posted by telstar

The heater wire inside the glass envelope had not been connected to the end of the terminal, but instead was left un-soldered inside.
Has anyone else experienced similar events?
Cheers
Mike

Inside the base to the pin or inside the glass envelope?

Its certainly not unknown for dry joints on Valve pins on B4, B5 and B7 bases.

Usually then can be re-soldered.

If it's inside the envelope then it looks as if a weld has failed that's usually the end of the story.

Cheers

Mike T

merlinmaxwell · 28th Oct 2020, 5:02 pm

When buying valves I am quite content to accept they may (only one so far) arrive faulty, for the one that was faulty the seller gave me a refund, no questions asked, for the cost and postage. That aside it may be the pin soldering as mentioned before.

telstar · 31st Oct 2020, 2:11 pm

Hi everyone.
Not sure if people understood the story. He did actually unsolder the tip of the valve terminal where it fits in to the socket. From there he discovered that the end of the heater wire had not been pulled through enough to reach the end of the valve for soldering. So, he looped some wire and tinned it and it manage to grab the wire inside the valve so it could be soldered. Hence the radio was no longer intermittent and it worked!

28th Oct 2020, 2:33 pm	#1
telstar Octode Join Date: Dec 2003 Location: Leeds, West Yorkshire, UK. Posts: 1,193	Cossor radio repair Hi. My brother was asked to repair an early Cossor 1930's radio recently which he managed to get working. However, it became intermittent and the cause of this became difficult to trace. Before this occurred he had to buy a replacement R.F valve from a supplier in Europe, and this turned out to be the fault. The heater wire inside the glass envelope had not been connected to the end of the terminal, but instead was left un-soldered inside. The supplier did not accept returns, and any way it was too late to return the faulty valve. Has anyone else experienced similar events? Cheers Mike

28th Oct 2020, 2:40 pm	#2
60 oldjohn Nonode Join Date: Dec 2004 Location: East Yorkshire, UK. Posts: 2,866	Re: Cossor radio repair Hi Mike, Sorry about the valve, are you able to take photo of the loose wire? then contact seller. What valve is it? worth asking on here if anyone has one to spare. John. __________________ My favourite text message "I'll be there in five minutes, if not read again"

28th Oct 2020, 5:02 pm	#4
merlinmaxwell Dekatron Join Date: Jul 2008 Location: Maidenhead, Berkshire, UK. Posts: 10,138	Re: Cossor radio repair When buying valves I am quite content to accept they may (only one so far) arrive faulty, for the one that was faulty the seller gave me a refund, no questions asked, for the cost and postage. That aside it may be the pin soldering as mentioned before. __________________ Cats have staff, it's dogs that have owners.

31st Oct 2020, 2:11 pm	#5
telstar Octode Join Date: Dec 2003 Location: Leeds, West Yorkshire, UK. Posts: 1,193	Re: Cossor radio repair Hi everyone. Not sure if people understood the story. He did actually unsolder the tip of the valve terminal where it fits in to the socket. From there he discovered that the end of the heater wire had not been pulled through enough to reach the end of the valve for soldering. So, he looped some wire and tinned it and it manage to grab the wire inside the valve so it could be soldered. Hence the radio was no longer intermittent and it worked!