Hi,

A good introduction to vacuum-tube Tek scopes is
"Oscilloscopes Selecting and Restoring a Classic"
by Stan Griffiths, W7NI (1992) (paperback, about $20)
It is a survey of Tek scopes from the beginning
through the 1960's, including your 585A.

If you go to qrz.com and "Get Callsign" W7NI,
you can get his email address.
Hopefully, Stan still has some books to sell.

I followed his troubleshooting hints,
and fixed intermittant problems in my 545.
The problem was that "Black Beauty" capacitors
in the regulated power supply had grown leaky over time.
These black tubular capacitors with color coded values
are used liberally in the regulted supplies
of the vintage Teks, and can cause strange
intermittant symptoms. I replaced all
of the the Black Beauty's with Mylar capacitors
found cheap on eBay.

I would not plunge in to working on the scope
until you are more experienced with working
around high voltage. The scope has a hefty power
supply and large storage capacitors, and can give
a painful or dangerous jolt to the unwary.

One caution: do not use regular 60-40 rosin core solder
with the Tek. That will ruin the ceramic terminal strips.
Instead, use Kester "Electronic Silver Solder"
62% tin, 36% lead, 2% silver.

73,
Ed Knobloch

zeitguy wrote:
snip The oscilloscope I found
is a Tektronix 585a, with 78 tubes and every single component is hand
soldered on ceramic strips. It seems to work, after I cleaned it up a
bit and learned enough to jump the Cal Out to the input on the dual
trace module to watch the square wave. But it also seems to drop out
or not respond consistently, and I don't know any where near enough to
go beyond watching the cal out trace at the moment. I can't wait to
probe my first radio circuit when I am reasonably sure I know enough to
not get electrocuted.