[Amps] Henry 4K-Ultra

[Bob Maser]

FWIW,  the 4KU that I am restoring/cleaning does not have a serial number 
plate on it so I was unable to tell how old it was.....until I spoke with an 
ex Henry employee this evening.  I asked him what the black hand written 
"FD-9" that is inscribed on the second floor of the power supply meant, if 
anything.  He told me that virtually all of the 4K's and also commercial amp 
power supplies were assembled and tested by Fay Danza and the number 
indicated the relative beginning or ending of the 4KU.  Since Henry made the 
4KU starting in 1971, this indicates that it was one of the early ones. 
This is in conflict with the fact that my amp has a ceramic 2500pf cap in 
the C2 position and supposedly they changed over to the ceramic after the 
glass caps were no longer available from Jennings.  It would be interesting 
to see the FD numbers of the other 4KU's out there.  One problem in seeing 
what your number is due to the fact that she wrote her ID on the left hand 
side of the 2nd floor of the power supply, part of which might be under the 
plate transformer.

I managed to buy the EBM 230V blower on eBay this evening so that will be 
installed as soon as I receive it.  $20 +$9 shipping ain't that bad.  Now, 
if I can find a suitable filter cap.

Bob W6TR