UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

ppppenguin · 29th Mar 2010, 12:59 pm

Half inch paintbrush is fine for most cleaning like this. Pulling out the LOPT for a clean and polish wasn't wise but you'll probably get away with it.

PL81s lead a hard life, look at the brown stains on any used specimen. It's a lot to expect of a small valve like this - I've always thought it miraculous that you could scan a fairly wide angle CRT and make EHT using a B9A valve. Yours was cracked and the vacuum gone which is mechanical damage. It could have been a latent weakness brought out by the repeated and harsh thermal cycling inherent in using a PL81.

29th Mar 2010, 12:59 pm	#84
ppppenguin Retired Dormant Member Join Date: Dec 2003 Location: North London, UK. Posts: 6,168	Re: Tv62 Half inch paintbrush is fine for most cleaning like this. Pulling out the LOPT for a clean and polish wasn't wise but you'll probably get away with it. PL81s lead a hard life, look at the brown stains on any used specimen. It's a lot to expect of a small valve like this - I've always thought it miraculous that you could scan a fairly wide angle CRT and make EHT using a B9A valve. Yours was cracked and the vacuum gone which is mechanical damage. It could have been a latent weakness brought out by the repeated and harsh thermal cycling inherent in using a PL81.