[Test-Equipment] Hickok 288X signal generator--update

[Pete Lancashire]

My 38 cents

Deoxit for the contacts, get the bottle not the spray. No need to waste it.

A good light oil for the bushings, Do not use WD-40 or 3-in-1  Check in
with the teletype guys, R-390'ers etc.

Ditto on any where grease is needed, my guess the 'clicker' on any rotary
switches will be the only place.

Caps; paper, oil, electrolytic replace

Carbon comp resistors, under 20 or so, replace them all. My guess being a
service grade instrment they did not use
A-B's or other hot moulded.  if your up to it. Inside any 'decks' consider
potential damage so there I sometime stay away.

The tough part is coils. Don't know the upper range of this guy, but
coatings can be an issue > 50-100 MHz. Do any
of the forms look warped, falling apart from moisture ? If so you may have
to think about cooking any moisture out,
again being a service grade, I'd only consider as a last step.

Internal wire .. cloth covered rubber ? if so losses really get bad over
5-10 MHz.

Is it 2 wire AC in ? If so consider making it 3 wire. Heck might even be
room for a IEC Socket/Line Filter. Your call
on preservation vs just for bench use.  Line fuse .. if there was not one,
add one.

Cabinet, dials, plastics .. just be careful, test what ever someone comes
up with in a place that does not show. If anything
is glass dont freak out, a good glass shop can work any shape you want in
single pane.

hmmm does it nave a meter ? if so and you consider taking it apart, dont
let is suck up bits of metal, put down a mat of some sort
before hand, i use to work for someone who repaired meters, use to be good
money in it but getting microscopic bits of iron out of
the movements sucks.

hmmm #2 does it have a light for any scales ? if so consider subbing with
a LED/resistor. A 1940's plastic scale that has not
seen heat in 20+ years can deteriorate quite fast from athe IR a #47 gives
off.

TAKE PLENTY of before and after pictures, I love to see them, I'm bet many
others do as well.

Another excuse for taking before pictures, they help in the putting things
back together :-)

-pete

.








On Mon, Apr 21, 2014 at 7:12 PM, Brian Burns <brian at lessonsinlutherie.com>wrote:

> Hello again Pete and All,
>
> Well duuuuh! With the slightest bit of searching I found that the Heath
> board is a square wave generator for scope calibrating, and was obviously
> added sometime in the mid 1970's.
>
> One comment on the Antique Radio Forum that made me laugh was "It's about
> as
> accurate as a sundial", but another disagreed, and said the board was quite
> accurate and useful.
>
> In any case the Heath pcb is quite irrelevant to the restoration process,
> and I'm open to any suggestions for how to proceed. Re-capping is pretty
> obvious, as is checking for resistors that are out of spec, and testing for
> weak tubes.
>
> I figure that it's poor economy to use less than the best replacement
> parts,
> and would really appreciate recommendations for types of caps and resistors
> to use, as well as what supplier to get them from.
>
> Thanks for all your help, guys!
>
> Cheers,
>
> Brian
>
>
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