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We have a lot of Tek parts and CRT's from 7000/5000 series and some
4xx series portable scopes. Happy to sell, swap and trade bits if
it will help get everybody's gear up and running, and we have a VERY
BIG surplus pile. We are always looking for 2xxx series CRTs and
parts.

we have tek parts cross-reference data both on line and in paper if
you need it, you can see the on line portion by going to our web
site, and following the trail to the test equipment portion.



all for now,
walter

walter2@...

Hi TekScope Fans,

I just wanted to let you know I am here and listening in
case you have a question or two I might be able to help you
with.

I want to thank the moderator of this forum for inviting me
to join.

Stan
w7ni@...

Hello, and welcome to the group. There's only about 10 of us so far, so if you can dig up some more members, or have ideas on finding more, great! I know there are tons of ham lists on eGroups -- I'll get around to *them* when my spectrum analyzer is ready! :-)

Although I've been aware of these instruments for a long time, and even used one about 20 years ago, it wasn't until I found a cheap source (don't ask! :-) that I became interested in acquiring some, more for actual use than to collect. They're just too big to want to have too many!

My present "good" collection includes a 502A dual-beam differential (newer version with PCB amps) and a 549 bistable split-screen storage with 1A4 & 1A5 plug-ins. (BTW, can anyone point out any real advantage to a scope like the 502 having dual beams...? On a scope with storage or multiple plug-ins, I can see some advantages, but the 502 has neither.) I also have a 1S1 sampling plug-in, and am awaiting the arrival of a manual to help me get it going again. The main problem might just be the missing diodes (sampling bridge and a few others). I'm hoping these are PIN or Schottky, and can be sub'd with something easily available.

My "less-good" scopes include an older 502A (with ceramic-strip amps) and a 556, a monster dual-beam that takes 2 plug-ins. Actually, this one probably just needs a bit of cleaning up to get it into good shape. I have a bunch of 1A1 2-channel plug-ins for it too.

As much as I hate to strip equipment like this, I'm certainly willing to do so with at least the older 502 and the 1A1s. If anyone needs parts, or whole units, get in touch.

-----------------------------------------------------------------
Michael Dunn | Surround Sound Decoder & Stereo Enhancement
Cantares | Self-Amplified Speaker Kits
74 George St. | Ambisonic Surround Sound CDs and Recording
Waterloo, Ont. | (519) 744-9395 (fax: 744-7129)
N2J 1K7 | mdunn@...
Canada |
-----------------------------------------------------------------

Michael Dunn wrote:

BTW, can anyone point
out any real advantage to a scope like the 502 having dual beams...?

Scopes like the 502 and later 502A (and still later 5030) were used a lot in
biomedical research. They were cheaper than storage scopes and had enough
sensitivity to directly observe a lot of the signals generated by animal
muscle movements and brain activity. In order to correlate two different
signals in the body (for example, brain activity and subsequent muscle
movement) you needed to monitor two points simaltaneously without the lost
of signal or noise that might be generated by sharing one beam using the
"chopped" mode.

The other dual beam scopes like the 551, 555, and 556 found uses in the
nuclear energy industry. In these cases, the signals were much faster than
those found in the biomedical industry (like in a nuclear blast) and whole
events were missed if the "alternate" mode of a dual channel amplifier was
chosen. Even in the "chopped" mode whole events could be lost between
samples taken at the chopping rate. The answer was to use more scopes
simaltaneously, or in some cases, the use of dual beam scopes could save you
from having to have multiple scopes.

Stan
w7ni@...

At 3:13 AM -0700 2000/9/08, Stan Griffiths wrote:

> BTW, can anyone point
> out any real advantage to a scope like the 502 having dual beams...?

In order to correlate two different
signals in the body (for example, brain activity and subsequent muscle
movement) you needed to monitor two points simaltaneously without the lost
of signal or noise that might be generated by sharing one beam using the
"chopped" mode.

Though frequencies are usually low in such work. Were contemporary chopped scopes all too noisy?

The other dual beam scopes like the 551, 555, and 556 found uses in the
nuclear energy industry.

Wouldn't one need storage to capitalize on their dual-beamedness?

Michael

Well, I finally got the manual for my 1S1 1GHz sampling plug-in. It's filled with exotic diodes. About 5 tunnel diodes of varying type and package. And, nine(!) GaAs (Gallium Arsenide) diodes (5 types!)!!! I had originally thought these were tunnels also, and no, they don't emit light ;-) I've never even heard of such things before - think they were actually made by Tek. Anyway, 6 of them are missing, and I'm thinking that some low-power Schottky diodes might be workable subs. Can anyone comment on this...?

thx

-----------------------------------------------------------------
Michael Dunn | Surround Sound Decoder & Stereo Enhancement
Cantares | Self-Amplified Speaker Kits
74 George St. | Ambisonic Surround Sound CDs and Recording
Waterloo, Ont. | (519) 744-9395 (fax: 744-7129)
N2J 1K7 | mdunn@...
Canada |
-----------------------------------------------------------------

Does anyone have any data on Nuvistors (miniature metal-envelope tubes), or have any to sell? I could use an 8056, and have some 7586s...

What we really need here is a genuine Tek engineering type that knows
circuit design using tunnels and GaAs diodes. I will see if I can recruit
one to join this reflector. This is way beyond a repair technician's (me)
capabilities.

Stan
w7ni@...

Michael Dunn wrote:

Hi,

I've joined this group for keep in touch with other enthusiasts of
old instruments, of course Tektronix too. Why does neary everybody
seems to fear publishing his name and some info about his person
here. Big Brother has better possibilities than looking for some odd
guys collecting T&M "trash".

By the way I've got a east german made "monster scope" (a real
boatanchor with tube count > 100, weight > 60kg and > 600watts pwr)
of appprox. 1968 which uses a very close copy of the Tek 545A crt. I
don't think they ever paid a licence fee (do you remember the Hickock
story?). Maybe I will try one of these "chinese" copy in a 545A
mainframe - just for fun.

Stefan

Guys (is Bobbi on here yet?),

I usually lurk in most email groups that I've joined. Note that this
is not fear-based; I usually won't post unless I feel I have something
worthwhile to contribute. I have had communications (via glowbugs/
boatanchors) with certain members of this list for awhile now. I
appreciate their generosity in sharing arcane knowledge and experience
concerning Tek equipment. I hope that nobody takes offense if I only
post occasionally. I always listen, however.

I have the following Tek equipment:

RM545B - my main scope. Needs calibration, which I'll get to when I
have time. The only bad component I've had so far was one of
those damn oil caps got leaky (6AU5 HV osc tank) and smoked
the cathode resistor.
555 - works. I haven't decided what to do with this one, though.
485 - I know it's solid state, but I picked up at a garage sale for cheap.
A 350 MHz scope comes in handy from time to time.
310 - needs a little work. Nice sized scope, good for audio work.

numerous 500-series plugins (some functioal, some not), including a 1M1
that Stefan was kind enough to offer to me (Thanks). No spectrum analyzer,
though.

Wants: 577 curve tracer for cheap.
570 (who doesn't?)

--
Dan Kerl
dlkerl@...

G'day... :)

(I'm sending this to the group as well as direct to you, Michael...)

Sometime on Mon, 25 Sep 2000, you wrote:

Hmmm, it took me a while to figure out what my email program was
telling me in the sender field! Now you too can experience the
phenomenon. What're the odds...?!

Well, for a while there I was wondering why my email program was sending me a
copy of a message I had sent to someone else...

The odds must be incredible.

And further to stretch things, I have a very good email friend in Sudbury,
Ontario, whom I've been corresponding with for many years now. - about the
*only* person I regularly correspond with... :) I wonder how far Sudbury is
from you...?

The more, the merrier.

Good... :) As I may have mentioned, the only Tek gear I have is an old TM503
with a DM501A and three custom plugin kits... :) I have uses planned for all
those, for Ham Radio test gear. The DMM was faulty, but fortunately it came
with manuals and I was able to repair it. :)

Sounds like a good place to have been.

It was *very* good. Conditions were excellent, as were the tools and equipment
(natch). We were, as I remember then, "committed to technical excellence."
I certainly believed so, and (I hope) my work reflected that.

I lucked out a while ago, getting a 7603(13?) in good condition,
with manuals & scopemobile, for the equivalent of under U$200!

Wow! Over here, that's about $400, but allowing for the generally lower
commodity prices in the US (about half) I guess I'm getting a good deal at
around $600. That's with the 7B53A, and I like a mixed sweep... :) It
apparently comes with two 7A26's as well. I'll be very happy if I can arrange
it.

Even better, a friend and I have been cleaning out the local university's
tube units (and other old things) for typically $5 each!!! If I can
get my 1S1 1GHz sampling plug going, I'll be REAL happy.

I bet! :) I understand such things *have* happened here, but you have to be
*very* lucky...

BTW, I wonder if there are any other Aussies on this list...?

Also BTW, I recently came across a site called "Bill & Stan's TEKTRONIX
resource site". They have reprinted some of the cartoons from the old service
manuals. That was a real "blast from the past" for me. <g>

Kind regards to all,
:)
Michael

--

Michael VK2XMD 0404-478-205
I used to have a handle on life, but it broke ...

Hi Everyone,

Well, if we are introducing ourselves, let me have a go...

My name is Arnoud van der Wel, and I am situated in Enschede, the
Netherlands. My 'discovery' of old Tek scopes started with a 533A/1A4 that I
bought at a sale of surplus equipment at my university for about $25. Being
too big for most people, apparently, that makes it somewhat 'worthless'?

My collection grew steadily, and now I have lots of old scopes... a 515, a
545A and B, a 585, 531, 561, 564 and 564B, and of more recent vintage... a
7514 with a VERY interesting intermittent HT fault :) and a 7904.

I used my 533A daily and to my full satisfaction until about a month ago,
when someone gave (!) me a 7904 in working condition with a box of 7k
plugins, which is now the scope on my bench.. At least the 533A has a worthy
successor. :) The best feature of the new scope is actually the fact that it
is so quiet... :)

I also made a 'Tek scopes museum' website one rainy afternoon, which can
still be seen at margo.student.utwente.nl/~wel/tek.htm but which hasn't been
updated for (far) more than a year now. A site like that is a lot of fun to
make and lots of people come by with enthousiastic comments, interesting
anecdotes, parts, stories and pictures..

Not having any time for the website now, and not being likely to in the near
future, I am looking for someone who wants to take what's there and give it
the care and attention (and updates!) it deserves.. If there are any takers
out there who want a good start to their own 'Tek Museum' drop me an email
and we'll talk. You start off with (amongst others) a link from the official
Tek site to your museum, so you'll have no lack of hits. :)

Oh, and on the subject of responses to my site.... This morning someone
offered me a 511A by email. I really have no space for it, but we can't let
this be thrown away, can we? He has a .nasa.gov email so I take it he is
somewhere in the states...

So long,

Arnoud.

Hi Arnoud, :)

Sometime on Thu, 28 Sep 2000, you wrote:

My name is Arnoud van der Wel, and I am situated in Enschede, the
Netherlands. My 'discovery' of old Tek scopes started with a 533A/1A4 that I
bought at a sale of surplus equipment at my university for about $25. Being
too big for most people, apparently, that makes it somewhat 'worthless'?

Unfortunately, these days, "small is beautiful"...

My collection grew steadily, and now I have lots of old scopes... a 515, a
545A and B, a 585, 531, 561, 564 and 564B, and of more recent vintage... a
7514 with a VERY interesting intermittent HT fault :) and a 7904.

Gee, I remember when a 7904 would have been worth a *lot* of money. I guess
that makes me old, huh... :/ Hmmm, what's a 7514?

I used my 533A daily and to my full satisfaction until about a month ago,
when someone gave (!) me a 7904 in working condition with a box of 7k
plugins, which is now the scope on my bench.. At least the 533A has a worthy
successor. :) The best feature of the new scope is actually the fact that it
is so quiet... :)

Ah, I remember repacking many, many fan motors.... <g>

I also made a 'Tek scopes museum' website one rainy afternoon, which can
still be seen at margo.student.utwente.nl/~wel/tek.htm but which hasn't been
updated for (far) more than a year now. A site like that is a lot of fun to
make and lots of people come by with enthousiastic comments, interesting
anecdotes, parts, stories and pictures..

I tried to access it, but my browser returned "unable to locate server". A
pity, as I'd like to have seen it.

Oh, and on the subject of responses to my site.... This morning someone
offered me a 511A by email. I really have no space for it, but we can't let
this be thrown away, can we? He has a .nasa.gov email so I take it he is
somewhere in the states...

Lucky devil... *Nobody* gives away Tek scopes around here... >sigh<.

Kind regards,
:)
Michael

--

Michael VK2XMD 0404-478-205
I used to have a handle on life, but it broke ...

I also made a 'Tek scopes museum' website one rainy

afternoon, which can

still be seen at margo.student.utwente.nl/~wel/tek.htm but

which hasn't been

updated for (far) more than a year now. A site like that is

a lot of fun to

make and lots of people come by with enthousiastic comments,

interesting

anecdotes, parts, stories and pictures..

I tried to access it, but my browser returned "unable to
locate server". A
pity, as I'd like to have seen it.

I just tried it and it is still there!

So the problem does not seem to be on my end of the line....

Regards,

Arnoud.

Hello all!

First post here for me, but I've been lurking for a little while.

I'm the proud owner of a later model 535A, complete with CA plugin, all
manuals, probes, and the scopemobile. After getting it home, pulling off all
the covers, and getting 40 years of tobacco tar residue off of it (thank
goodness for the smoke-free workplace of today), it looks almost brand new.

Firing it up had it working well, but I did track down a bad pass tube in the
power supply, causing a low voltage on one of the supplies. After that, it
works perfectly, and has a very strong CRT.

It was used at Eaton here in Milwaukee in it's former life, and did some pulse
testing, so it has a camera mount in place of the normal round bezel. It also
had the fan replaced with a 5" muffin style unit some years ago, no doubt a
common conversion in the later years as the originals went south. It really
blows some air, but isn't the quietest thing going.

I use the scope for my audio hobby and it's a treat to use. The engineering
that went into it boggles my mind. The quality is amazing, and to have it
function perfectly after all these years is a real testament to what can be
done with "obsolete" technology.

I also have a dead 422 solid state scope (power supply) that's in really nice
cosmetic condition, but I just don't have the time to fiddle with it. If
anyone is looking for one for parts, let me know. I'd be interested in
obtaining a proper round bezel for my 535A in trade.

That's about it! It's nice to see these technical marvels preserved. Sure,
they are hot, noisy, and big, but when I flip that big switch, it is soooo
much more satisfying that pushing the little button on my Hitachi 40MHz
scope.

Chris Beck


____________________________________________________________________
Get your own FREE, personal Netscape WebMail account today at

At 8:57 PM +1100 2000/9/28, Michael Dunn wrote:

Ah, I remember repacking many, many fan motors.... <g>

Tell us more please! The fans on our 549s don't work too well - they start out seized, and as the scope warms up, they start to spin, eventually reaching a decent speed...

-----------------------------------------------------------------
Michael Dunn | Surround Sound Decoder & Stereo Enhancement
Cantares | Self-Amplified Speakers, Test Equipment
74 George St. | Ambisonic Surround Sound CDs and Recording
Waterloo, Ont. | (519) 744-9395 (fax: 744-7129)
N2J 1K7 | mdunn@...
Canada |
-----------------------------------------------------------------

G'day... :)

Sometime on Fri, 29 Sep 2000, you wrote:

At 8:57 PM +1100 2000/9/28, Michael Dunn wrote:

Ah, I remember repacking many, many fan motors.... <g>

Tell us more please! The fans on our 549s don't work too well -
they start out seized, and as the scope warms up, they start to spin,
eventually reaching a decent speed...

Hmmm... Well, now you're asking! :) It's 25 years since I did one, but It was
simply a matter of removing the fan motor and disassembling it, then cleaning
with Freon TF (not available now, but many substitutes out there) and
reassembling; adding new fibre washers as necessary. I was always amazed that
this had such a dramatic effect.

But it *was* one of those tedious, messy jobs nobody likes much.....

BTW, Chris commented about the muffin fans not being the quietest thing. I
added a 12VDC one to a computer (this computer) and the noise drove me crazy.
So I ran it from the 5V supply, and it's almost inaudible, though it still
pushes the air around. No doubt a noise vs efficiency compromise could be
found in the scope situation. :)

And ditto his comments about engineering. :) My guess is, that's why we're
all here...

Regards,
:)
Michael

--

Michael VK2XMD 0404-478-205
I used to have a handle on life, but it broke ...

Sometime on Thu, 28 Sep 2000, you wrote:

I just tried it and it is still there!
So the problem does not seem to be on my end of the line....
Regards,
Arnoud.

Hmmm... I double-checked the url (I'm having trouble with this mail program and
web addresses), so I wonder what the problem is? I'll try again today...

Regards,
:)
Michael

--

Michael VK2XMD 0404-478-205
I used to have a handle on life, but it broke ...

Sometime on Thu, 28 Sep 2000, you wrote:

I just tried it and it is still there!
So the problem does not seem to be on my end of the line....

I just tried again, and same result. :(

By substituting "www" for "margo.student" and dropping the "/~wel/..." I was
able to get to the university, but was unable to get to your page that way. Is
the server name correct...?

Regards,
:)
Michael

--

Michael VK2XMD 0404-478-205
I used to have a handle on life, but it broke ...

Is anyone familiar with the characteristics of Nuvistors? I ask because I do have some data sheets, but the curves don't look like normal tubes or FETs. Instead of a mostly constant-current section, the Nuvistor curves are resistive in nature. The grid voltage seems to modulate the resistance somewhat, and also sets the threshold plate voltage at which the tube starts to conduct! Am I missing something, or are Nuvistors really that different?

thx

-----------------------------------------------------------------
Michael Dunn | Surround Sound Decoder & Stereo Enhancement
Cantares | Self-Amplified Speakers, Test Equipment
74 George St. | Ambisonic Surround Sound CDs and Recording
Waterloo, Ont. | (519) 744-9395 (fax: 744-7129)
N2J 1K7 | mdunn@...
Canada |
-----------------------------------------------------------------