Columbia Model 229B 78 rpm Record playing unit

[signalman4]

Hi Gary,
Yes please, I would welcome that coil of yours. At least it would enable me to put it all back together and play records.

Ed, what units are you giving for the minimum wire size of 0.063 for the inexperienced.
I measure the original wire with my trusty micrometer as 2 thou diameter.

Mike, I dont suppose the inductance of the coil is very much but I've seen my DMM going crazy when trying to measure a mains transformer primary and the DMM kept switching ranges.

Alf

[PerdioPal]

"DMM going crazy" try a battery in series with the coil and current setting on the meter, just like they used to do!

[Radio Fixer]

On other Forums I would say send me a PM with with your Email or address and we could fix that up !

On here I cant see it but maybe you know, or someone does?

Gary

[Mike Watterson]

Click on the envelope icon.

[Mike Watterson]

"DMM going crazy" try a battery in series with the coil and current setting on the meter, just like they used to do!

Yes, that works. Not too much current and don't hold the bare wires. Disconnect gives a big kick!

[ppppenguin]

DMM going crazy when trying to measure a mains transformer primary and the DMM kept switching ranges.

Two other tricks that can help.

1: If it's a transformer (won't help for a single coil) short out another winding. The reflected impedance will then be much less awkward for the DMM

2: Put a resistor in parallel with the winding to be measured, possibly around or less than the expected resistance. Then measure the resistor separately and do the sums.

[Radio Fixer]

Thanks Mike

Gary

[Refugee]

The easy way is to use an analogue meter if you have got one.

[Mike Watterson]

The easy way is to use an analogue meter if you have got one.

That's why I have kept the AVO. A plastic tube with Lithium coin cells does the HT battery with 10 years life and no leaking.

[DrStrangelove]

The easy way is to use an analogue meter if you have got one.

That's why I have kept the AVO. A plastic tube with Lithium coin cells does the HT battery with 10 years life and no leaking.

Thanks, that's a good idea, though I never noticed the B121 layer cell doing much leaking. (Then again I haven't seen one in 30 years).