Date   

Re: Scope humour

Rex W. Athey <mister_twister@...>
 

That reminds me of why tubes and transistors love to play baseball. They like to watch those electrons go from 1st base to home plate.

Rex


Re: Caig (Any way to clean...?)

Greyhawk <greyhawkeng@...>
 

There Is An Interesting Article Here About Caig Labs And
Cramolin Red Here:

http://www.pitt.edu/~szekeres/caigcram.htm

Greyhawk

----- Original Message -----
From: Fred Olsen
To: TekScopes@yahoogroups.com
Sent: Friday, January 16, 2004 21:18
Subject: [TekScopes] Re: Caig (Any way to clean...?)


Miroslav Pokorni wrote:
> My experience with those 'miracle lubricants' has been that they are snake
> oil and that includes Caig Lab. I tried their DeoxIT with very indifferent
> results,

Since the original question regarded pots I would remind all that DeoxIT
is intended for connector, switch, and relay contacts. Caig's
recommended product for carbon and conductive plastic pots is CaiLube MCL.

While I too have had mixed results with Caig's current products, they do
work fairly well in their intended applications. Overhyped and
overpriced though, and products from Chemtronics and others work darn
near as well.

It seems though that 'everyone' has forgotten about the original
product, Cramolin, from the original Caig Labs in New York. Cramolin
'red' was a thin liquid cleaner/preservative, Cramolin Special (green)
was just a preservative for new or clean contacts, and Cramolin Paste
was for high voltage / high current use. There was also a Paste-G which
was graphite-filled. I think that they had a mineral oil base.

The stuff had an odd smell, and the 'red' turned colors when it attacked
oxides, but it really worked quite well. Or works, I should say, as I
still have some and have used it regularly for 35+ years. It is
intended to be applied in a very thin film, near molecular, and so a
little goes a long way.

As I recall it, not well, the products were produced by the original
Caig under license or some other sort of proprietary agreement and are
no longer available from the present company. A search of their site
will turn up references to them as discontinued products. A source for
something like the original compounds still exists in Germany. The
whole product line is named Cramolin, from ITW Chemische Produkte GmbH.
http://www.cramolin.de/

Fred
--
<><
--
Outgoing checked by Norton AV




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What kind of cap is that ?

plasmatec2000
 

Hi,

I got a lot of caps that are labeled Tektronix

http://www.beautyphoto.de/tektronix.jpg

and I wish to know what material is the foil.

The foil is transparent with light green cast.
Not possible to stretch,
makes harsh sound when touching,
plastic foil and aluminum foil are separat,
is this cheap MKT ?


Re: 7104 Service Manual wanted

nr1dx@...
 

Bruce

The other email address you just sent "returned fatal errors"

Dave


From: "Bruce Lane" <kyrrin@bluefeathertech.com>
Date: 2004/01/16 Fri PM 09:31:31 GMT
To: tekscopes@yahoogroups.com
Subject: [TekScopes] 7104 Service Manual wanted

Hi, gang,

OK... I've checked my usual sources. Cheapest price I've seen so far for a service manual (original Tek hardcopy) for the 7104 was $135.00.

That really seems kind of high. I know there's at least a couple of listmembers who sell manuals -- that being the case, I'd like to hear from you if you can beat that price.

The serial number involved is B021884.

Thanks much.
-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
kyrrin (at) bluefeathertech do/t c=o=m
"If Salvador Dali had owned a computer, would it have been equipped with surreal ports?"




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To visit your group on the web, go to:
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Re: GR, not Tek!

Miroslav Pokorni
 

A very interesting site, Craig.

I find it amazing that Teradyne put such an effort in preserving GR's
history. Even more so, when it is common after acquisition of a company to
obliterate any sign of existence of acquired company, kind of 'plow the salt
into the fields'.

Regards

Miroslav Pokorni

----- Original Message -----
From: "Craig Sawyers" <c.sawyers@tech-enterprise.com>
To: "TekScopes" <TekScopes@yahoogroups.com>
Sent: Thursday, January 15, 2004 4:21 PM
Subject: [TekScopes] GR, not Tek!


Hi all

Anyone interested in the history of GR, I found a downloadable 1916
catalogue here
http://www.teradyne.com/corp/grhs/pdf/catalog-bulletins/Catalog_A_1916.pdf
.
In fact this is just a section in the General Radio Historical Society on
http://www.teradyne.com/corp/grhs/ - it seems to have lots of fascinating
stuff there if you like the early history of electronics.

Enjoy!

Craig


Re: Any way to clean...?

Miroslav Pokorni
 

Your experience with Electrolube would be of great interest, I daresay, for
group as a whole. In particular, over long term, say six months or longer.

My experience with those 'miracle lubricants' has been that they are snake
oil and that includes Caig Lab. I tried their DeoxIT with very indifferent
results, improvement lasted a week or so and it was back to where I started.
Then, I tried Caig's 'R5 Power Booster', with similar results. You must have
heard of Caig's 'battery challenge', apply R5 to an old flash light and
'watch it come back to life'. I applied it to a new flash light that would
go dim after a while and when you pull batteries out and re-insert them, the
light works fine for a week or so. I tried R5, pulled batteries out, cleaned
all surfaces (batteries and contacts) with R5, few times each, re-assembled
the flash light and in a week I was where I started. After few tries with
R5, I substituted water for R5, with same results. Than I did not use any
'cleaner', just rubbed batteries and contacts with dry cloth and again light
lasted a week or so, so buying DeoxIT or R5 was a waste of money and effort.

I recognize that rubbing surfaces (pots, connectors, switches etc.) need a
lubricant to reduce wear and smooth operation, but those promised miracles
just appear to be snake oils.

Regards

Miroslav Pokorni

----- Original Message -----
From: "Jeff W" <vwthingy@cox.net>
To: <TekScopes@yahoogroups.com>
Sent: Thursday, January 15, 2004 9:58 PM
Subject: [TekScopes] Re: Any way to clean...?


Bruce wrote:
Does anyone know of a way to clean the (apparently sealed)
pots on the front panel of a 7000 series?

I have found that the cycling them results in a very temporary fix.
I have become pretty good with taking apart these pots, cleaning
them, and putting them back together. In the past, I used to just
collect the excess grease and recycle it, but I recently picked up a
couple tubes of Electrolube contact oil to try out.

Jeff


Re: Replacing CC resistors

Miroslav Pokorni
 

And low inductance should not be forgotten. Those dastardly carbon
compositions are quite irreplaceable as (50 Ohm) terminating resistors.

In these days, ceramic composition is offered as replacement for carbon,
with low inductance, high surge etc., but no one is talking about long term
stability. Examples are Ohmite's 'OX', 'OY' and 'Little Demon' series.

Construction of those ceramic composition resistors appears to be same as
that for carbon composition, so the same problems might crop up past 1000
hours standard test for resistors. A true hermetic seal would certainly
improve long term stability, but that is a difficult proposition. It appears
that only thing that would do that trick is a layer of glass or glassified
ceramic around resistive element and phenolyc encapsulant to provide
mechanical protection for that fragile sealing material, but that would
drive price of resistor sky high.

Regards

Miroslav Pokorni

----- Original Message -----
From: "Michael Dunn" <mdunn@cantares.on.ca>
To: <TekScopes@yahoogroups.com>
Sent: Friday, January 16, 2004 2:26 PM
Subject: [TekScopes] Replacing CC resistors


Yes, old carbon comp resistors *can* drift. Just a thought: if
you're replacing CCs with film resistors, keep in mind one of CC's
attributes - their high surge capacity. Analyze or measure the
circuit (most likely during turn-on), and overrate the replacement's
power if necessary.

Michael



TEK 485 Question

w1ksz <w1ksz@...>
 

I think I found the cause of the trace shifting on my 485. One end
of the Position Pot (R1300) goes to +13v. The voltage drops slowly
to 11.5v as the scope "warms up". Now I just have to locate where
the +13v comes from. The power supply schematic doesn't show it, and
the reference to the A Time Base Generator schematic doesn't help.
Does anyone know where it comes from ?

Thanks, Dick, W1KSZ


Re: 7104 Service Manual wanted

Miroslav Pokorni
 

Hello Bruce,
I got manual for my 7104 from Deane Kidd ( dektyr@teleport.com ). Back in
1998 it cost me $50. Take heart, I got cheap manual but paid close to $800
for scope with only two plug ins (only one was 7A29).

Regards

Miroslav Pokorni

----- Original Message -----
From: "Bruce Lane" <kyrrin@bluefeathertech.com>
To: <tekscopes@yahoogroups.com>
Sent: Friday, January 16, 2004 1:31 PM
Subject: [TekScopes] 7104 Service Manual wanted


Hi, gang,

OK... I've checked my usual sources. Cheapest price I've seen so far for a
service manual (original Tek hardcopy) for the 7104 was $135.00.

That really seems kind of high. I know there's at least a couple of
listmembers who sell manuals -- that being the case, I'd like to hear from
you if you can beat that price.

The serial number involved is B021884.

Thanks much.
-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
kyrrin (at) bluefeathertech do/t c=o=m
"If Salvador Dali had owned a computer, would it have been equipped with
surreal ports?"


Re: Tek475 strangely in heat

Miroslav Pokorni
 

A possibility to consider is that there were heat sinks on them at one time.
They might have fallen off or someone smart decided that scope works just
fine without those damn things and removed them.

Regards

Miroslav Pokorni

----- Original Message -----
From: "josko_flander" <josko_flander@yahoo.com>
To: <TekScopes@yahoogroups.com>
Sent: Friday, January 16, 2004 9:56 AM
Subject: [TekScopes] Tek475 strangely in heat


Hi!

I have recently acquired an old Tek475 scope and although it works
great I was tempted to poke my nose in it. There I found something
strange. A pair of double transistors (Q914 and Q938) is literarily
steaming. They are too hot to touch. I have made some preemptive
measurments (compared the voltages in the circuit to those in the
schematics) but it all checks fine. I was wandering if it is their
normal working temperature or they are overheating and are about to
die.

Any comment would be sincerely appreciated!

Thanks!

Josko Flander


Re: 5L4N

Miroslav Pokorni
 

The 5L4N appears to be 5000 series equivalent of 7L5, with upper frequency
somewhat reduced: frequency range is 20 Hz to 100 kHz, dynamic range 80 dB.
There is a built in tracking generator and asymetrical and symetrical input.

These data is coming from 1995 Tucker's catalog, could not find it in
Tektronix catalogs that I have as hard copies. To indicate demand for those
units, Tucker's asking for 7L5 was $4900 and a $3800 could get you a 5L4N.

As for 'what do you do with 15 pieces', you parcel them out and if you do
not make money on it, shipping companies will.

Regards

Miroslav Pokorni

----- Original Message -----
From: "Stefan Heinzmann" <stefan_heinzmann@yahoo.com>
To: <TekScopes@yahoogroups.com>
Sent: Friday, January 16, 2004 9:45 AM
Subject: [TekScopes] 5L4N


Hi all,

there's a lot of 15 5L4N spectrum analyzer plugins on ebay at the
moment (item 3071668755). Never heard of those, are they any good?
1000 Euros for 15 of them means less than 70 for each one. How do they
compare to a 7L5? Bargain?

(Now don't ask me what you do with 15 at a time...)

Cheers
Stefan



Re: 7104 Service Manual wanted

nr1dx@...
 

Bruce

I tried to email you direct but your email address bounced??? Contact me , I can help you out.

Dave
NR1DX


From: "Bruce Lane" <kyrrin@bluefeathertech.com>
Date: 2004/01/16 Fri PM 09:31:31 GMT
To: tekscopes@yahoogroups.com
Subject: [TekScopes] 7104 Service Manual wanted

Hi, gang,

OK... I've checked my usual sources. Cheapest price I've seen so far for a service manual (original Tek hardcopy) for the 7104 was $135.00.

That really seems kind of high. I know there's at least a couple of listmembers who sell manuals -- that being the case, I'd like to hear from you if you can beat that price.

The serial number involved is B021884.

Thanks much.
-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
kyrrin (at) bluefeathertech do/t c=o=m
"If Salvador Dali had owned a computer, would it have been equipped with surreal ports?"




Yahoo! Groups Links

To visit your group on the web, go to:
http://groups.yahoo.com/group/TekScopes/

To unsubscribe from this group, send an email to:
TekScopes-unsubscribe@yahoogroups.com

Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/



Re: Replacing CC resistors

Dave Wise
 

They're also less inductive.

Dave Wise

-----Original Message-----
From: Michael Dunn [mailto:mdunn@cantares.on.ca]
Sent: Friday, January 16, 2004 2:26 PM
To: TekScopes@yahoogroups.com
Subject: [TekScopes] Replacing CC resistors


Yes, old carbon comp resistors *can* drift. Just a thought: if
you're replacing CCs with film resistors, keep in mind one of CC's
attributes - their high surge capacity. Analyze or measure the
circuit (most likely during turn-on), and overrate the replacement's
power if necessary.

Michael


TDS700A Field Adjustment Software

DANNN31
 

Does anybody have a copy of the TDS 700A Field Adjustment Software? Got a
TDS744A and a TDS754A that need a little dialing in.

Thanks,
Dan


Replacing CC resistors

Michael Dunn <mdunn@...>
 

Yes, old carbon comp resistors *can* drift. Just a thought: if you're replacing CCs with film resistors, keep in mind one of CC's attributes - their high surge capacity. Analyze or measure the circuit (most likely during turn-on), and overrate the replacement's power if necessary.

Michael


Re: Tek475 strangely in heat

adenton <adenton@...>
 

Hot means too much current at too much voltage -- power = volts x
amps and all that. If the voltages are OK look for excessive
current. High heat is NOT normal. A common cause of excess current
is a leaky capacitor, either supplying excessive base current, or for
example in bypassing an emitter resistor thus greatly increasing
emitter/collector current.

Depending on the circuit configuration, it is possible for this to
happen without apparent malfunction, especially in a differential-
amplifier circuit. Since yours are duals, I strongly suspect that.
Check all those caps for leakage. Strap a current meter in one of
the emitter circuits and measure the juice. This times the CE
voltage gives you the power dissipation which you can compare against
the case type. (Although you already know it's too high.)

Note, caps sometimes check OK at low voltages (VOM ohmmeter) but leak
like fishnet at circuit voltages. Perhaps a current-meter in series
with the cap, with the circuit quiescent. (If it's in the sweep, try
single-sweep mode etc.)

Which suggests a topic, Does anyone know anything about electrolytic
capacitor leakage??? (JUST KIDDING!!!)

--- In TekScopes@yahoogroups.com, "josko_flander"

A pair of double transistors (Q914 and Q938) is literarily
steaming. They are too hot to touch.


Scope humour

Michael Dunn <mdunn@...>
 

Came across this joke as a young lad, and though I knew what a 10:1 probe was, it took a friend and I literally several years before we "got it"! If you don't understand, try saying it out loud a few times.

Q: Why are they called 10:1 probes?

A: Because when left unattended, they 10:1 away.


7104 Service Manual wanted

Bruce Lane
 

Hi, gang,

OK... I've checked my usual sources. Cheapest price I've seen so far for a service manual (original Tek hardcopy) for the 7104 was $135.00.

That really seems kind of high. I know there's at least a couple of listmembers who sell manuals -- that being the case, I'd like to hear from you if you can beat that price.

The serial number involved is B021884.

Thanks much.
-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
kyrrin (at) bluefeathertech do/t c=o=m
"If Salvador Dali had owned a computer, would it have been equipped with surreal ports?"


Re: GR, not Tek!

regman10
 

Thanks Craig,
Very interesting site. It made me appreciate my V5 Variac (in almost daily
use for over 30 years) and decade resistor box even more.

"Subject: [TekScopes] GR, not Tek!"


Tek475 strangely in heat

josko_flander
 

Hi!

I have recently acquired an old Tek475 scope and although it works
great I was tempted to poke my nose in it. There I found something
strange. A pair of double transistors (Q914 and Q938) is literarily
steaming. They are too hot to touch. I have made some preemptive
measurments (compared the voltages in the circuit to those in the
schematics) but it all checks fine. I was wandering if it is their
normal working temperature or they are overheating and are about to
die.

Any comment would be sincerely appreciated!

Thanks!

Josko Flander

180881 - 180900 of 187119