Cleaning Valve Bases

[Petedox]

I've just got caught with an intermittent valve base connection on an Leak TL12 Plus.

Years ago, as a TV man I generally gave them a squirt and a bit of a wiggle - job done! However time has moved on and I'm finding some bases are becoming very resistant to cleaning. I guess many of us have come across this problem from time to time. They can of course be changed, but I would generally prefer to keep the original base wherever possible.

My question is, does anyone have a proven cleaning technique that works for them?

[snowman_al]

Have you looked down the holder at the forks?
They do become spread or even snapped in half over time. Russian valves with pointed pins easily go down the side rather than the centre of the fork.

You can 're-tension' the forks with a strong needle (switch off and discharge the caps first!) or replace snapped ones.

[G6Tanuki]

Yes, if the bases are the typical type with the contact-forks being stamped from brass, the combination of age, heat and tension often causes cracking where the 'legs' of the fork come together. Particularly a problem on the B7/B8/B9 type bases but not unknown on octals either - and can cause some very frustrating "It's working.... no it isn't.... yes it is...." faults until you become acquainted with it.

There used to be available some very nice US-made Octal bases with turned tubular phosphor-bronze contacts and PTFE insulation. Alas I've not seen these on sale for quite some time (nor would I want to pay an inflation-adjusted version of the price they cost back then!).

[stacman]

Looking through an old A.C Farnell catalogue, pity the item in the middle of the page isn’t still available.....
Regards, Alan