Scott,
I don't know if this was mentioned about the internals to the FC-30 I've
seen myself. I received an amplifier (home brew) with an FC-30 that had a
broken case. I pop'd the box open to find two separate chokes, routed to
separate posts/leads at each end of the box. To get the 30A spec, the two
15A chokes are paralleled at the ends of the box with short jumpers. That
was how this amplifier was built and worked well.
I don't know if later versions had a single rod 30A choke, I just make
mine now from single rods avail at Amadon wound with help from a lathe...
73's
skipp wv6f
nospam4me@juno.com
Those with long memories will recall I was whining about insufficient
filament voltage in my (2)3-500Z amp...
Well, I solved that problem by biting the bullet and finding room on the
RF
deck for the xfmr. Now instead of a pair of 7' runs of #10 (which
subsequent calculations showed was *not* sufficient!) I have a pair of 3"
runs. I was able to verify the xfmr using a bank of 6 1ohm 25W resistors
to duplicate the load of a pair of 3-500z filaments.
The amp is GG so there's an old B&W FC-30 (or could be FC-30A...don't
know
'cuz the stickerplate fell off). Right now I'm getting 0.18V drop across
each choke...for a total of 0.36V. With a choke input of 5.00V
(measured),
that's 4.64V at the tubes, I'M STILL A LOSER. Darn!
Well that drop seems awfully surprising for a choke supposedly rated at
30A
service.
So, here's the litany:
1. Are there known issues like this with the B&W FC-30(A)?
2. Any known OE's (Operator Errors) which could lead to this drop across
the choke?
3. ...each end of the choke has four terminals, apparently arranged in
pairs. If you mount the choke "on its feet" (it has little tab feet on
the
bottom), the top two terminals are closer together than the left or right
pair (in other words, the four terminals form a rectangle that's longer
vertically than horizontally). *Which pair is the "choke"???? Ohming it
out won't tell me anything and I've never seen one in use!
4. Anything else?
Thanks again to the planet,
------------
Scott Townley
nx7u@primenet.com
------------
Collector of:
Stoddard Aircraft EMI/RFI receivers and accessories
Big Parts for that Big Linear Amp
70's era RF test equipment HP/GR/Tek
Radio-related technical reference material 1940+
...anything else that will keep me off the streets at night
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