Date   

Re: Troubleshooting a TM500 series plugin

Jim Ford
 

True, Victor.

I've just been looking for used test equipment at work over the last few weeks, and from my admittedly small sample set of 2, the price the used MTE (Measurement and Test Equipment) dealers want for calibrated and warrantied equipment is roughly double what you'd find on ebay.

My boss had me look up a rubidium frequency standard and a frequency counter, roughly $2000-3000 items. I assume they just figured out that the old pieces they have could drop out so we should have some backup, or the boss had some $$ in an account that needed to be spent or it would go away, or both.

Of course the dealers said Well, you could buy a brand new counter for $XXXX. No, we want an old one in case the one we have takes a dump (and we don't want to spend the extra dough on a new one!)

The trick now is actually getting the things in plant. Shipping is difficult, or so the dealers tell me...

FWIW.

Jim Ford

------ Original Message ------
From: "victor.silva via groups.io" <daejon1=yahoo.com@groups.io>
To: TekScopes@groups.io
Sent: 4/15/2020 2:55:11 PM
Subject: Re: [TekScopes] Troubleshooting a TM500 series plugin

What a company and a hobbyist will pay are two different things.
If a company really needs something, any price under $1000 is petty cash for most companies.

That's why there are prices like that on ebay.

--Victor



Re: Troubleshooting a TM500 series plugin

victor.silva
 

What a company and a hobbyist will pay are two different things.
If a company really needs something, any price under $1000 is petty cash for most companies.

That's why there are prices like that on ebay.

--Victor


Re: Any Tektronix magnetic shield for a CRT? A strange problem...

Tony Fleming
 

Thanks Ernesto! You are a wealth of information!
I need to clone your brain and copy it to mine! ha ha ha

On Tue, Apr 14, 2020 at 9:29 PM Roy Morgan <k1lky68@...> wrote:

Tony,

As I remember, mumetal is not a material that has a coating: it is stuff
like copper sheet in that it is metal all the way through. The material has
very high magnetic property coefficient of magnetization, called mu (a
Greek letter).

I remember cautions on CRT shields to not bend or deform the thing,
presumably because it's shielding quality would be decreased if that
happened.

A related material was coated on some medium-based vacuum tubes in the
1930's. Called "aqua-dag" (I think), it may well have been a slurry of
similar material. It's use allowed radio designers to not install metal
tube shields, presumably saving some money.

Certain UTC audio transformers were made with one or more shields made of
mu-metal to reduce induced hum and/or noise.

Roy

Roy Morgan
K1LKY Western Mass

On Apr 14, 2020, at 9:46 PM, Tony Fleming <czecht@...> wrote:

Interesting solution! What kind of coating is on it?

On Tue, Apr 14, 2020 at 8:04 PM Ernesto <ebordon@...> wrote:
Today i received from EMR Shielding Solutions a piece of mumetal film,
0.1 mm (!) thick, permeability mu = 25,000,




Re: Any Tektronix magnetic shield for a CRT? A strange problem...

 

You may be right about this not being the traditional mumetal.
They don't call it so, instead they name it "WMF200:Magnetic Shielding Film"
"It is a specialized magnetic shielding film made from an amorphous cobalt alloy"
This company EMR Shielding Solutions give it a commercial name "WOREMOR WMF200"

And there has been some inflation.... For this little sheet I paid a total of $39.25.
But I'm happy that I bought it.

Ernesto


Troubleshooting a TM500 series plugin

 

I found a DS-503 universal counter plugin in my set of Tektronix plugins. This unit was showing the LED display but was not counting at all.

Interested in troubleshooting it, I looked at ways to reach its inside while powered up, something like an extender cable.
I googled for it, and the only one I saw was on ebay, an authentic (but used) Tektronix cable, at $224.95 + $8.45 shipping = $233.40.
WHAT? for a used extender cable of an antique instrumentation system?

So my empty TM-504 (four bays) had the upper cover and the upper front bracket removed (total 8 screws).
The DS-503 had the left cover removed to access its board with the input analog stuff and some triggers.
The DS-503 was placed in the right-most slot of the TM-504, which was then stood up on its right side.

There was plenty of comfortable space to view and access the left side of the plugin.
The problem was quickly identified as the lack of the -22V on this top board.
The cause was traced to an open-circuit of the filter inductance at the -22V input to the board.

The repair was done using the method in the recent thread "PCB component replacement".
The failed inductor was clipped off and replaced with a nice short jumper wire.

Had there been a need to access the right side of the DS-503,
it would have been placed in the left-most slot of the TM-504, then stood up on its left side.

If I had googled "TM-500 extender BOARD, I would have seen several offers at reasonable price.
But I won't need either in the future.

What I may need when I repair my 7704A is an extender board or cable for its plugins.
I will tackle this when the time comes. In the meantime I saw at ebay an offer:
"Tektronix 067-0589-00 B022137 Plug-in Extender Calibration Fixture", $730 refurbished. LOL!

Ernesto


Re: Any Tektronix magnetic shield for a CRT? A strange problem...

Ed Breya
 

Aqudag and related stuff can be used for many things besides CRTs. The conductivity is good for anti-static purposes, and the nearly pure flat blackness is good for optical uses. It is used to coat certain internal surfaces of optical assemblies to absorb stray light, or as part of optical devices. Just last night I was sorting through some of my optical junk boxes, and found a black-body radiator/absorber piece, which is basically a metal cylinder with a conical bore. The whole thing is generously coated inside and out with carbon dag.

Although my terminology isn't proper - I say "dag" for any kind of liquid-suspended particles - there are other kinds made from silver or copper, for instance, that have high conductivity, and are used for shielding and grounding, and electrical connections on delicate components, in lieu of solders. You could also call all of these things conductive paints or glues.

The real, original aquadag function, by another name, is India ink - used for thousands of years before CRTs came along.

Ed


Re: Tek 465B parts for sale

exojam825@...
 

John,

My apologies, the only reason I was linking the items posted here to what is also posted on eBay was so that pictures of the items, and measurements from some of them could be seen.

Also, since I was only posting in one thread I really did not feel I would be taking away from folks that are posting in search of assistance if they are in need of help,

James


Re: Any Tektronix magnetic shield for a CRT? A strange problem...

Richard Solomon <dickw1ksz@...>
 

Sounds more like Co-NETIC Metal.

73, Dick, W1KSZ

On Wed, Apr 15, 2020 at 9:50 AM Ed Breya via groups.io <edbreya=
yahoo.com@groups.io> wrote:

Ernesto wrote;
"Well, this mumetal sheet felt like there was a plastic cover, and some
plastic extended beyond the mumetal material.
The manufacturer specifies its materials as: Polyester, Co69, Fe4, Mo4,
Nb1, Si16, B7.
Being the sheet so thin, only 100 microns, could explain why its curvature
does not affect the annealing of the metal."

It looks like this must be a newer alternative to traditional mu metal. If
your alloy info is correct, there's not even any nickel in it, which is a
major ingredient in the original high performance permalloys and mu metals.
If your thickness info is correct, then this stuff is pretty amazing
magnetic shielding, with such a thin layer of actual material. The plastic
lamination must be to insulate it and hold it together mechanically -
otherwise it would be a foil.

Ed




Re: Any Tektronix magnetic shield for a CRT? A strange problem...

Ed Breya
 

Ernesto wrote;
"Well, this mumetal sheet felt like there was a plastic cover, and some plastic extended beyond the mumetal material.
The manufacturer specifies its materials as: Polyester, Co69, Fe4, Mo4, Nb1, Si16, B7.
Being the sheet so thin, only 100 microns, could explain why its curvature does not affect the annealing of the metal."

It looks like this must be a newer alternative to traditional mu metal. If your alloy info is correct, there's not even any nickel in it, which is a major ingredient in the original high performance permalloys and mu metals. If your thickness info is correct, then this stuff is pretty amazing magnetic shielding, with such a thin layer of actual material. The plastic lamination must be to insulate it and hold it together mechanically - otherwise it would be a foil.

Ed


Re: Artek Manuals

Tam Hanna
 

Hello,

on the risk of a beating: if you want to scrap the 577 because of a dead CRT, do NOT do it.


A fix is forthcoming. Send an e-mail OFF LIST, saying STINKELY.


Tam

--
With best regards
Tam HANNA

Enjoy electronics? Join 15k7 other followers by visiting the Crazy Electronics Lab at https://www.instagram.com/tam.hanna/


Re: Any Tektronix magnetic shield for a CRT? A strange problem...

Siggi
 

On Wed, Apr 15, 2020 at 7:25 AM Colin Herbert via groups.io <colingherbert=
blueyonder.co.uk@groups.io> wrote:

You may be misremembering what "Aquadag" is used for. My memory is that it
was used to coat the inside of CRTs beyond the deflection plates. If I'm
remembering correctly, its job was to catch errant electrons, but I may
well be misremembering myself (Covid-19 does that to you). What I do recall
is that there was "Oildag" as well as "Aquadag" and that the "dag" part
stood for "Deflocculated Acheson Graphite". So it was finely-ground
graphite suspended in oil ("Oildag") or water ("Aquadag").
I hope this adds a little to the discussion.
Colin.

Looks like you're in agreement with Wikipedia on the composition and use
of AquaDAG: https://en.wikipedia.org/wiki/Aquadag. It sounds like it was
also used to shape the electrostatic field at the front of the CRT. I do
seem to remember a mention of the use of various coatings in this Tektronix
CRT video: https://youtu.be/G0Dci5RPe94.
Incidentally a fun video to watch, it was an incredibly detailed process to
build those CRTs.


Re: Any Tektronix magnetic shield for a CRT? A strange problem...

Colin Herbert
 

You may be misremembering what "Aquadag" is used for. My memory is that it was used to coat the inside of CRTs beyond the deflection plates. If I'm remembering correctly, its job was to catch errant electrons, but I may well be misremembering myself (Covid-19 does that to you). What I do recall is that there was "Oildag" as well as "Aquadag" and that the "dag" part stood for "Deflocculated Acheson Graphite". So it was finely-ground graphite suspended in oil ("Oildag") or water ("Aquadag").
I hope this adds a little to the discussion.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Roy Morgan
Sent: 15 April 2020 03:29
To: TekScopes@groups.io
Subject: Re: [TekScopes] Any Tektronix magnetic shield for a CRT? A strange problem...

Tony,

As I remember, mumetal is not a material that has a coating: it is stuff like copper sheet in that it is metal all the way through. The material has very high magnetic property coefficient of magnetization, called mu (a Greek letter).

I remember cautions on CRT shields to not bend or deform the thing, presumably because it's shielding quality would be decreased if that happened.

A related material was coated on some medium-based vacuum tubes in the 1930's. Called "aqua-dag" (I think), it may well have been a slurry of similar material. It's use allowed radio designers to not install metal tube shields, presumably saving some money.

Certain UTC audio transformers were made with one or more shields made of mu-metal to reduce induced hum and/or noise.

Roy

Roy Morgan
K1LKY Western Mass

On Apr 14, 2020, at 9:46 PM, Tony Fleming <czecht@...> wrote:

Interesting solution! What kind of coating is on it?

On Tue, Apr 14, 2020 at 8:04 PM Ernesto <ebordon@...> wrote:
Today i received from EMR Shielding Solutions a piece of mumetal film,
0.1 mm (!) thick, permeability mu = 25,000,


Re: DAS9100 does anyone still remember it

Brian
 

Hi Dan
Thankyou for letting me know its there . Sneaky addition to the command set that shift key . I have V1.11 in my DAS and I have been worried that something was wrong as the Define Mnemonics menu was different to the pictures in the manual - I shall have to try the shift key and see if all becomes good . None of that is mentioned in any documentation I have seen .The Define menu has 2 sub menu's , the mnemonic entry menu is different to the manual and the 2nd menu does not seem to work as the manual suggests .
I must go and play

Brian

On Wednesday, 15 April 2020, 00:31:03 BST, Dan G <dgajanovic@...> wrote:

On Fri, Apr 10, 2020 at 07:02 PM, Dan G wrote:

I could not find this version of section 7 online, so I will scan my copy and
upload it to TekWiki in the next few days.
The new version of the DAS 9100 Operator's Manual Section 7 is now
available on the TekWiki. The major change is the addition of the
Table Definition sub-menu (accessed by holding SHIFT while pressing
the DEFINE MNEMONICS key). This seems to be a significant new feature
that was added to the DAS firmware at some point, and makes it possible
to disassemble arbitrary and rather complicated instruction sets.

My guess is that this feature was probably not present in early firmware
versions, though I do not know when it was first added. I can confirm that
v1.09 firmware has the new sub-menu.

Happy disassembling!

dan


Re: Artek Manuals

Gary Robert Bosworth
 

Dave: Check out the 577 Curve Tracer Service Manual. The circuit boards
are close to worthless.

Gary

On Sat, Apr 11, 2020, 16:40 ArtekManuals <manuals@...> wrote:

Garry

Which manual are we talking about?

Dave


On 4/11/2020 7:28 PM, Gary Robert Bosworth wrote:
I don't mind the schematics being copied in Black & White, but I would
prefer the circuit boards to be done in gray scale. Any overlay writing
on the circuit boards becomes illegible against the background when the
boards are done in strictly black & white..

On Sat, Apr 11, 2020 at 3:21 PM Bruce Lane <@kc7gr>
wrote:

Most definitely. I've been a very happy customer for many
moons.
Dave
does some of the clearest scans I've ever seen.


On 11-Apr-20 14:56, Bill via groups.io wrote:
Are the Artek manuals full page? Some online manuals are very hard to
read and if you enlarge them they go off the page.
Bill


--
---
Bruce Lane, ARS KC7GR
http://www.bluefeathertech.com
kyrrin (at) bluefeathertech dot com
"Quando Omni Flunkus Moritati" (Red Green)



--
Dave
Manuals@...
www.ArtekManuals.com


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus





Re: Any Tektronix magnetic shield for a CRT? A strange problem...

Jim Ford
 

Regarding aqua-dag, see Dagging on the Microwaves 101 Slang page, about a dozen page downs from the top.
https://www.microwaves101.com/encyclopedias/microwave-slang

Jim Ford

------ Original Message ------
From: "Roy Morgan" <k1lky68@...>
To: TekScopes@groups.io
Sent: 4/14/2020 7:29:28 PM
Subject: Re: [TekScopes] Any Tektronix magnetic shield for a CRT? A strange problem...

Tony,

As I remember, mumetal is not a material that has a coating: it is stuff like copper sheet in that it is metal all the way through. The material has very high magnetic property coefficient of magnetization, called mu (a Greek letter).

I remember cautions on CRT shields to not bend or deform the thing, presumably because it's shielding quality would be decreased if that happened.

A related material was coated on some medium-based vacuum tubes in the 1930's. Called "aqua-dag" (I think), it may well have been a slurry of similar material. It's use allowed radio designers to not install metal tube shields, presumably saving some money.

Certain UTC audio transformers were made with one or more shields made of mu-metal to reduce induced hum and/or noise.

Roy

Roy Morgan
K1LKY Western Mass

On Apr 14, 2020, at 9:46 PM, Tony Fleming <czecht@...> wrote:

Interesting solution! What kind of coating is on it?

On Tue, Apr 14, 2020 at 8:04 PM Ernesto <ebordon@...> wrote:
Today i received from EMR Shielding Solutions a piece of mumetal film,
0.1 mm (!) thick, permeability mu = 25,000,



Re: Any Tektronix magnetic shield for a CRT? A strange problem...

 

Well, this mumetal sheet felt like there was a plastic cover, and some plastic extended beyond the mumetal material.
The manufacturer specifies its materials as: Polyester, Co69, Fe4, Mo4, Nb1, Si16, B7.
Being the sheet so thin, only 100 microns, could explain why its curvature does not affect the annealing of the metal.

Ernesto


Re: Any Tektronix magnetic shield for a CRT? A strange problem...

Roy Morgan
 

Tony,

As I remember, mumetal is not a material that has a coating: it is stuff like copper sheet in that it is metal all the way through. The material has very high magnetic property coefficient of magnetization, called mu (a Greek letter).

I remember cautions on CRT shields to not bend or deform the thing, presumably because it's shielding quality would be decreased if that happened.

A related material was coated on some medium-based vacuum tubes in the 1930's. Called "aqua-dag" (I think), it may well have been a slurry of similar material. It's use allowed radio designers to not install metal tube shields, presumably saving some money.

Certain UTC audio transformers were made with one or more shields made of mu-metal to reduce induced hum and/or noise.

Roy

Roy Morgan
K1LKY Western Mass

On Apr 14, 2020, at 9:46 PM, Tony Fleming <czecht@...> wrote:

Interesting solution! What kind of coating is on it?

On Tue, Apr 14, 2020 at 8:04 PM Ernesto <ebordon@...> wrote:
Today i received from EMR Shielding Solutions a piece of mumetal film,
0.1 mm (!) thick, permeability mu = 25,000,


Re: Any Tektronix magnetic shield for a CRT? A strange problem...

Tony Fleming
 

Interesting solution! What kind of coating is on it?

On Tue, Apr 14, 2020 at 8:04 PM Ernesto <ebordon@...> wrote:

Success!!

Today i received from EMR Shielding Solutions a piece of mumetal film,
0.1 mm (!) thick, permeability mu = 25,000, size 4" wide x 24" long.
This sheet was like paper and came rolled up into a small tube, all the
way from Ontario Canada. I thought: "is THIS a magnetic shield?

I first looked at the little scope and saw the 60 Hz waves on the trace at
the most notorious sweep rate.
Then I opened the scope up, and in a few minutes I wrapped that "mumetal
paper" around the neck of the CRT.
Closed back the scope without further change, powered it up and...
MIRACLE! not the slightest sign of any 60 Hz interference!

Thank you all for your good suggestions!

Ernesto




Re: Any Tektronix magnetic shield for a CRT? A strange problem...

 

Success!!

Today i received from EMR Shielding Solutions a piece of mumetal film, 0.1 mm (!) thick, permeability mu = 25,000, size 4" wide x 24" long.
This sheet was like paper and came rolled up into a small tube, all the way from Ontario Canada. I thought: "is THIS a magnetic shield?

I first looked at the little scope and saw the 60 Hz waves on the trace at the most notorious sweep rate.
Then I opened the scope up, and in a few minutes I wrapped that "mumetal paper" around the neck of the CRT.
Closed back the scope without further change, powered it up and... MIRACLE! not the slightest sign of any 60 Hz interference!

Thank you all for your good suggestions!

Ernesto


Re: DAS9100 does anyone still remember it

Dan G
 

On Fri, Apr 10, 2020 at 07:02 PM, Dan G wrote:

I could not find this version of section 7 online, so I will scan my copy and
upload it to TekWiki in the next few days.
The new version of the DAS 9100 Operator's Manual Section 7 is now
available on the TekWiki. The major change is the addition of the
Table Definition sub-menu (accessed by holding SHIFT while pressing
the DEFINE MNEMONICS key). This seems to be a significant new feature
that was added to the DAS firmware at some point, and makes it possible
to disassemble arbitrary and rather complicated instruction sets.

My guess is that this feature was probably not present in early firmware
versions, though I do not know when it was first added. I can confirm that
v1.09 firmware has the new sub-menu.

Happy disassembling!

dan