Replacing VCR heads

[Ken_B]

I've ordered new heads on order for my Mitsubishi HS-U71.

I removed the old one to examine it, and noticed while replacing it that
there is a little rotational "play" between the drums (1 degree, maybe)
before soldering and before the screws are tightened. Is the final position
critical, and if so how do you align it?

 

[Sofie]

"Ken_B" <ken5229"at"softhome.net> wrote in message

I removed the old one to examine it, and noticed while replacing it that
there is a little rotational "play" between the drums (1 degree, maybe)
before soldering and before the screws are tightened. Is the final
position
critical, and if so how do you align it?
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Ken_B:
The mechanical tolerance you noted is normal and is compensated for with
electrical adjustments.
Once the new upper drum is installed, a factory alignment tape and
oscilloscope is used for proper adjustments.
The PG Position in the servo circuitry and the Chroma & Luminance levels on
the preamp need to be checked and adjusted. The preamp RF envelope is
inspected for symmetry and proper levels and the roller guides are adjusted
if necessary.
Some non-tech types will claim that they can skip these steps but quite
obviously they are not optimizing the performance of the new head drum when
mated with the VCR. Not only can the performance be compromised but
tracking and "interchange" with other properly aligned VCRs could be
impaired.
A good shop will always perform the above procedures.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
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