Quote:
Originally Posted by Studio263
The impedance roller falling apart was a common problem with the Hitachi VTRs before the VT-11.
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Yes I had almost forgotten about that design feature!
The brass impedance roller was carried on a plastic insert shaped like a bobbin.
In hot weather (I suppose) the brass would expand and pop off one or other of the "cheeks" of the bobbin. It was a 50/50 chance, but if it was the top cheek it had no impact on operation unless you warned to operate the machine on its side or upside down(!) If you noticed the shim of plastic on the roller when servicing you cut it with snips and removed it.
If the lower cheek cracked then the brass roller dropped so it was only in contact with half the width of the tape and the lose plastic shim/cheek fouled the rollers' rotation. The cure for that was simple, I think we simply turned the bobbin over so the intact cheek was at the bottom. If not, a strategically applied blob of RS adhesive would have cured it.
Sounds like a bodge, but replacing the assembly with a new one just risked a repeat performance.