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 A box of dirty valves
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 Return to top of page · Post #: 1 · Written at 4:34:47 PM on 30 April 2023.
Graechel's Gravatar
 Location: Tamworth, NSW
 Member since 27 January 2023
 Member #: 2536
 Postcount: 13

I have been given a box of around 50 valves from long storage so are somewhat dusty.
Some identification is visible but many are difficult or impossible to be read.
I am wary of trying to clean and risking removal of what may still be there.
I have been advised to try using a white LED torch and will give that a go in next day or two.

In the end what do I do with unidentified valves? I am reluctant to donate them to the Red wheelie bin.

Any other experience out there to help things along?


 
 Return to top of page · Post #: 2 · Written at 4:39:18 PM on 30 April 2023.
Tallar Carl's avatar
 Location: Latham, ACT
 Member since 21 February 2015
 Member #: 1705
 Postcount: 2161

Donate them to Robbert he like to grab them.


 
 Return to top of page · Post #: 3 · Written at 4:53:40 PM on 30 April 2023.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6720

I am wary of trying to clean and risking removal of what may still be there.

Yep, don't try to clean them. The printing will come off very easily.

Various techniques for revealing what might be there:

Hot breath on the surface
Putting valve in freezer for a while
Ultraviolet light (aka black light)

what do I do with unidentified valves?

Some can be identified by the internal structure, however that would take an experienced eye.


 
 Return to top of page · Post #: 4 · Written at 6:57:38 PM on 30 April 2023.
Robbbert's avatar
 Location: Hill Top, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 2039

Donate them to Robbert he like to grab them.

Yes, I will take them off your hands, and I have ways to identify most valves.


 
 Return to top of page · Post #: 5 · Written at 9:41:06 AM on 1 May 2023.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5303

If you are fortunate to have something like the AVO Valve tester analyser. That helps immensely especially if your eye can tell a pentagrid from a diode and I would agree with ID of valves by their structure.


 
 Return to top of page · Post #: 6 · Written at 9:40:37 PM on 15 May 2023.
Robbbert's avatar
 Location: Hill Top, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 2039

The valves arrived today, one broke on the way (might have been a 6F6G). I was able to identify all but 2 of them. One of those is either a 32 or 34, the other looks like it might be a 78.

Most of the valves were ancient pre-octal types, mostly 4-pin, but with some 5 and 6 pin types. There was one 3-pin Philips 373 as well.
Of the few octals, 2 are battery types, and the others a scattering of various heater voltages. There was also a vibrator that looks brand new - complete with a vermin-chewed applications sheet.

The ones that could be of use in the radios we work on are 57, 6D6, 6U7G, 6G8G, 6F6G. There's also a type 83, but I'm fairly certain that it's gassy.

Haven't tested anything yet.

To help me, I used an ultra-violet light globe (the type that could display a signature in an old-fashioned bank passbook). Unfortunately after a while it blew up with pyrotechnics. I do not know if it's possible to get a replacement.


 
 Return to top of page · Post #: 7 · Written at 7:21:12 PM on 16 May 2023.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6720

I do not know if it's possible to get a replacement.

These days I'd use something like this: https://www.jaycar.com.au/uv-light-3w-with-adjustable-lens/p/ST3446


 
 Return to top of page · Post #: 8 · Written at 8:13:04 PM on 16 May 2023.
Robbbert's avatar
 Location: Hill Top, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 2039

Thanks, that's most interesting. Could be just the thing.

Turns out Bunnings sells a few different types of UV/blacklight globes too.


 
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