[Test-Equipment] HP-606A Calibration question

[Barry]

> Q Dope is still sold by General Electronics (GC)
> 
> As far as the 606A make sure that none of the plates have been bent. If so
> straighten them out. Ive yet to see the dial loosen up and use that as an
> absolute last resort. Ive overhauled many 606's over the decades and its
> rather easy to get the alignment within the dial line width by following
> the manual.
> 
> Carl
> KM1H

Hi Carl,

All I've seen in the manual is to adjust the L at the low end and the C at the top end of each range.  I don't recall seeing 
anything about linearity or other preparations for calibrations that effect linearity.  Is there something else to this that 
I've missed?

As I said, the variable capacitor on this one is pristine so, no, I wouldn't attempt to bend the fins.  Even as a last resort, 
I'm sure all I'd do is make things worse if I tried that.  The dial plate was lose when I got (it was way off from where it 
should have been by 15 degrees or more) it so I really don't know where it was originally.  I've disassembled and reassembled 
most of the dial mechanism to clean it and get everything working smoothly again.  If small rotational differences can make a 
difference in calibration/linearity, then this may very well be the problem here.  If not, I'm not sure what else to do.

BTW, when you say "within the dial line width", do you mean over the entire range?  I think the spec is 1% which I assume is a 
bit wider than that.  Wow.  If these will stay within line-width accuracy, then I'll be a very happy camper.

Thanks,
Barry - N4BUQ