I tested the cap and it showed about a half meg of resistance. maybe
something is shorted somehwere else. Oh, and I checked the voltage between
the record player chassis and the scope chassis - 120VAC (I thought that's
what it felt like). Odd though, I would think with 120v on the chassis that
it would pop a fuse at the breaker box.

Thanks


"CJT" wrote in message
...
CJT wrote:

tempus fugit wrote:

Tried the turining around the plug trick, but it made no difference. I
also
disconnected the phono plug that connects the tone arm to the amp unit,
which also made no difference.

Here is something curious though. I accidentally touched my scope
while my
hand was on the record player chassis and got a fairly good shock. The
scope
has a 3 prong AC plug (the record player doesn't). I should've
measured the
voltage difference between the sope chassis and the record player
chassis,
but I didn't think to. I'll have to do that. Perhaps he chassis is
live. I
didn't think this would be the case though, since there is a cap with
the
negative connected to the case, as well as a few other green wires.


That capacitor might be leaking or (worse) shorted. It can be a lethal
failure (I read just this week about a minister in Waco who was
electrocuted during a baptism when he grabbed a microphone that was
"hot."). Be careful.


Here's a cite to that story:
http://www.cbsnews.com/stories/2005/...in995829.shtml

Thanks


"Asimov" wrote in
message
...
"tempus fugit" bravely wrote to "All" (27 Oct 05 11:17:42)
--- on the heady topic of "unit hums loudly regardless of volume"

tf From: "tempus fugit"
tf Xref: core-easynews sci.electronics.repair:346437

tf Hey all;

tf I'm trying to repair an old tube portable record player. When it
is
tf on, it hums really loud, regardless of the volume.

Have you tried turning the ac plug around?

Which way the plug is inserted matters with these. Let the record
player warm up, then insert the plug one way or the other, and then
paint a mark for which was the quietest way. One way: lots of hum, the
other: quiet hiss.

Those old tube units used to get B+ directly from the powerline (or
sometimes a voltage doubler) and used a large value resistor bypassed
by a 0.01uF to RF ground the tone arm shielding to neutral. The power
for the filaments often came from a secondary winding in the motor
coil. Don't use this type of record player near the bathtub. Lethal!

Another possibility is a broken wire at the cartridge.

A*s*i*m*o*v

... Just a little force field zap.






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