Look for 105 deg C, Low ESR, High Frequency caps. Find caps designed for
bypass and decoupling in digital circuits--switching power
supplies,logic boards, and the like.
Check the Mouser catalog--I think they are currently listing some
Chemicon brand parts of this nature. I also used a bunch of Nichicon
Type PL which is a now obsolete series with decent specs.
Many manufacturers provide "motherboard" grade caps--Rubycon MCZ, Sanyo
Oscon...best place to find these is ebay surplus. Search "motherboard
cap" You won't find these in all required values but for some of the
higher C decoupling caps, like at the input to the logic board, these
would be great to use.
There is often some leeway in cap value but this needs to be determined
on a case by case basis. Obviously, QSK and AVC time constant caps, for
example, must be the same value as the original (unless you want to
change the time constants--not a bad idea for SSB AVC).
While you are working on the IF/AF board, do the LOGIC BOARD and the
DISPLAY DRIVER board. In fact I'd do those first. The reduction in
internal noise when you redo these boards with good fresh modern caps is
remarkable.
These are a few electrolytics behind the heatsink...make sure you
replace those also using good 105 deg C parts.
A few other Omni V owners on the list have done this rebuild and all
report fantastic results. With modern caps, you can make that radio
better than new. Except for the recently discussed shortcomings in
computer interface, I'd put the rebuilt Omni V on the table next to
anything.
Joe N5KAT
Steve Berg wrote:
I have taken the Omni V off the desk since I got the Corsair II PTO back
from Ten Tec, and I want to replace the electrolytics on the audio/IF
board. It has been many years since I specified a capacitor, and those
were chip ceramics, so what brands and models have the appropriate
qualities for this sort of service?
Thanks,
Steve WA9JML
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