Re: Tektronix 535 scope for coiling use

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Ed Phillips <evp@xxxxxxxxxxx>

Tesla list wrote:
>
> Original poster: Rich Simpson <richcreations@xxxxxxxxx>
>
> On Apr 10, 2005, at 7:33 PM, Tesla list wrote:
>
> >Original poster: "Ralph Zekelman" <gridleak@xxxxxxxxxxxxxx>
> >
> >I may have one of those little pots. If I can help it will take several
> >days.
> >Is this the variable V INPUT on the end of the INPUT selector?
> It is the variable knob on the end of the Volts/CM knob for channel A,
> part# is 311-116 (on clear cap on back of pot) it also says 650ohm, it is
> small (about 1/2" dia not including ears, black, has ears for mounting
> screws, and a small (~1/8") hole with setscrew for the shaft from the face
> of the unit, it is made of plastic...
>
>   also it only has two terminals, so I guess it would be a variable
> resistor, and not really a pot?
>
> several days matters not, as it is the only scope I have, and I will need
> to fix it, if you happen to have an extra or two (the channel B pot is
> working, but not very well) let me know, and we can work something out...
> -Rich

	I just looked at my 53C plugin, which is very similar, with the big
exception that the subject pot is a good old 2 watt Allen Bradley.  Much
sturdier and more reliable!  I looked at the pot you're speaking about
and think you could easily jury rig a 1/2 watt 1k pot to serve just as
well, shut it down with a 1.5k if you want to reduce the gain control
range a bit.  The other alternative is to just use a separate pot which
you can set for correct maximum gain and leave until you get a better
one.  You'll have a bit of a problem getting it it, even with the cover
off, but if you're hot to use the scope that should be better than
nothing.  Are you sure you can't clean up the B channel pot by squirting
contact cleaner into it and working it back and forth?

Ed