Month 9 of 1953?
Month 5 of 1939?
What is the tube type?
Has the tube been tested?
Is the tube any good?
Date codes can not prove the condition of the tube;
And date codes can not prove the match, or non-match, to a tube of another date code, or even of the same date code.
Is this a valuable tube that will be sold for $$$?
Test first, ask questions later. :^)
Month 5 of 1939?
What is the tube type?
Has the tube been tested?
Is the tube any good?
Date codes can not prove the condition of the tube;
And date codes can not prove the match, or non-match, to a tube of another date code, or even of the same date code.
Is this a valuable tube that will be sold for $$$?
Test first, ask questions later. :^)
Find a tube tester, and test it again. 25 years can make the tube less capable, and can do that to me too.
I have always found the best tube testers are a working tube circuit.
Yes, you have to be careful as you bring the tube up to full voltage; a Variac and one or two DMMs can monitor the tube as you slowly bring it up. Lots of work to do it that way, but worth the try.
I have always found the best tube testers are a working tube circuit.
Yes, you have to be careful as you bring the tube up to full voltage; a Variac and one or two DMMs can monitor the tube as you slowly bring it up. Lots of work to do it that way, but worth the try.
The usual date code is YWW. 1955, week 39 (or third quarter - some used 13, 26, 39, 52 instead of the exact week). Most went to 4 digits in the '60s (i.e. 6539) . Military and some industrial customers insisted on open date codes; consumer one usually got letter codes, known only to manufacturer and dealers.