David Campbell wrote on 3/6/2020 10:14 AM:
651B 1975 edition.
Replaced all of the electrolytics and tantalums, quite a chore to get the exactly correct values
Several caps were replaced with two or three in parallel. Same or better tolerance and voltage.
BEWARE. I bought what were advertised as Spragues from Mouser, they came with 30-50 YEARS of oxidation on the leads. Severe oxidation which indicates either very old stock or storage in an aggressive atmosphere. The caps in the unit had much less oxidation.
<snip>
Hello, Dave--
Were there any date codes on the Sprague caps? Thirty years ago might
register as, for example, 2690 (i.e., the 26th week of 1990).? Codes vary
among manufacturers, but IIRC Sprague used <two-digit week> <two-digit year>
format.
If there are no date codes present, the caps could be counterfeit.
I'm very surprised to learn that Mouser could be selling such old
stock-- you might consider writing them a letter of complaint.
73--
Brad? AA1IP
73--
Brad? AA1IP
