[Cheesehead]

I think it is shutoff circuit.
I'm going to look into a bypass or repair.u



On May 27, 12:33=A0pm, Audio Empire wrote:
On Fri, 27 May 2011 06:00:10 -0700, Audio Empire wrote
(in article ):





On Thu, 26 May 2011 19:41:34 -0700, Cheesehead wrote
(in article ):

Picked up a used TD145. =A0Thought it was a bargain.
But when the arm approaches the last track it will often
go to a loud hum with no discernable audio.
Could this be the arm wiring?
Is this a problem you've noticed or has been documented before?

Yes It is the wire and yes I've seen it before on other 'tables. Usuall=
y it's
caused by a wire being twisted as the arm traverses the record at some =
point
causing a broken connection. Often it's the shield that parts, or perha=
ps
something shorts-out. You'll have to look. Best to remove the wires fro=
m the
cartridge and using an ohm meter, ring out each wire in turn while movi=
ng the
arm about and noting which wire loses continuity at some point in the a=
rms
traversing arc. If you have to get the internal wiring replaced, you li=
kely
cannot do that yourself, and it might not be worth having it done, even=
if
you can find somebody in this day-and-age who knows how.

I'd like to add, that while it COULD, conceivably, be the cartridge, itse=
lf,
it's unlikely. Reason? Usually the cartridge connections (internal and
external), don't move in relation to the arm, so were it the cartridge, t=
he
hum probably wouldn't =A0be related to the POSITION of the arm relative t=
o it's
position on the record, but rather would either randomly come and go, or =
be
bad all the time. The exception might be if the cartridge itself were a
moving coil and the greater skating force toward the inner-grooves pulls =
on
one coil lead more than another causing a loss of connection on one of th=
e
channels. Moving magnet or moving iron (variable reluctance) types of
cartridges have rigidly mounted coils and they don't ever move relative t=
o
the cartridge body.