WOPL400 “Jesse”

Carl182 said:
Placeholder post:
PROBLEMS
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OK then, back to the only PROBLEM "Jesse" has. Every help is greatly appreciated!

When the power switch is turned OFF, the Channel A (Left) VU Meter:
- Goes back and stands still at -20 (OFF) position;
- After 10 seconds (amp is OFF remember), pegs VERY rapidly to -1 position;
- From there, takes 12 seconds to slowly go back at -20 (OFF) position.

Some considerations:
- Channel B (Right) VU Meter is OK;
- Channel A VU Meter is responsive when ON, BUT is slightly "behind" Channel B by 0,5 units or so;
- Voltage check on bias and speaker binding posts: it is absolutely equal and steady when comparing L and R;
- This was the only meter which pegged violently at turn-on BEFORE WOPLing/restoring the unit. This PL400 had the common problem of frying speakers via rail voltage, the reason why it was abandoned by previous owner;
- Below a closeup of the meter type from Honeywell. As per WO instructions and documentation, it is NOT the one type I could calibrate (if I understood right).

Some questions:
1) Is the thing gone for good? I really san't see how to operate here...
2) As per pics above, this is the meter extremely close to the new power caps, which are way larger than the originals. Electromagnetism? Aliens?
3) Would the White Oak LED Board somehow solve this?

Thanks in andvance for any help or considerations!
Carl

20210827_113211.jpg
The Meter BEFORE WOPLing/relamping.

20220127_170554.jpg
The meter AFTER WOPLing/relamping (switched it from B to A).
 
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Carl, those things are close to 50 years old. And they were POS's when new. The only different you could do is feed the meters post DC protect so they didnt take in rush voltage. If they are a little sticky take a " bounce" dryer sheet and de-static the plastic lenses.
And yes those big caps could influence the meters, to an extent that's noticeable....dont know for sure .
 
The old meters aren’t zero adjustable. The later ones I’ve had apart to access the movement, the clip together and can be carefully opened with a fine screwdriver. I’m not sure about the older meters but you might be able to open them and gently tweak the needle to sit at zero statically.
 
The Powerful Difference said:
Oops! AngrySailor, thanks for sharing your hands-on experience! I got faked by the photo. Q: Isn't it illegal to sell a meter that can't be properly zeroized? :0)

Anyway, the troubleshooting prior to that should be valid...

Trust, but verify --

3D
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The meter you pictured is the later 400/1 meter and is zero adjustable. I’ve never worked on an old
Meter but I’m 99% sure it’s been stated many times they are not adjustable as the later series one meters are.
 
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