[Boatanchors] EF Johnson thunderbolt

KA2PTE ka2pte at 3950.net
Sun Jul 4 18:23:43 EDT 2021


One other question I have is regarding these green 0.005uF RF bypass caps 
all over the chassis:

https://www.mediafire.com/view/vhyal4a0pwxbcdz/HPIM0855.jpg/file

With a chassis about 60 yrs old, I think it pays to replace all these, 
however no voltage rating is given in the manual.
I think that logo is for the company, Allen Bradley? Not sure. Would anyone 
know the general voltage for them, or if they are maybe
class 3 type RF?

One of these on the AC input recepticle was destroyed and I have a load of 
Xicon (p/n: 140-202p9-472k) class 1 ceramic disc caps I bought yrs ago which 
are 2kv rated at 0.0047uF and put one in there.

As this amps been modified from AB2 to AB1 and has about 3KV plate voltage 
on it from an external supply, should these caps be even higher rated?
So far all the ones I have tested are ok, no leakage -  but the most volts I 
can apply for a test is 600VDC.

--
Steve Hearns
KA2PTE



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