Date   

Re: DC508 HELP with PHOTOS option 7

 

Hi Miguel,

TM503 is just a 3 slot mainframe. That can't possibly be what you are referring to as Option 7. It might be part of the option since, presumably, you will want to have the TR502 and the DC508 in the same TM503 main frame. There are probably a few interconnections you need to make on the back plane of the TM503 between the TR502 and the DC508 to make them work together.

Dennis Tillman W7PF

-----Original Message-----
From: Miguel Work
Sent: Wednesday, March 06, 2019 11:54 AM

Hi, I had bought a DC508 option 1 for my TR502 7L14. I need to install
option7, TM503 is option7, manual is very clear, but It will be very useful a
detailed photos from cables and connector. Has some body one and can post
some photos?
Thanks
Regards

Miguel


--
Dennis Tillman W7PF
TekScopes Moderator


Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

 

Hi Wilson,

Ace Hardware, a US Hardware Store Franchise, and TrueValue Hardware Stores (another US Franchise) sell 99% IPA by the gallon for $20. I have not found it cheaper anywhere, and you can't beat the convenience of getting it anytime you want it at the local hardware store.

Dennis Tillman W7PF

-----Original Message-----
From: Bill Carns
Sent: Tuesday, March 05, 2019 5:28 PM

If you go to a pharmacy and talk with the Pharmacist, they can give you IPA
with a higher percent IPA and less water. This is better for pots, but be
careful to not saturate. Sometimes you can damage the carbon resistance
layer that is laid down for the wiper to run on. I am not sure if that is
true for the ones TEK uses.

Bill

-----Original Message-----
From: wilson2115@outlook.com
Sent: Tuesday, March 05, 2019 7:13 PM

I have some 91% Isopropyl Rubbing Alcohol sitting around and I have a Tek 577
with dirty horizontal and vertical display controls, I have used this to
clean residue on circuit boards and grime off surfaces and it works quite
well so I was wondering if it could be used to clean the dirty potentiometers
on the 577 curve tracer. 91% seems the best the best I can find. I also have
a can CRC Lectra Clean. What are your thoughts, recommendations? Thanks



--
Dennis Tillman W7PF
TekScopes Moderator


Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

Chuck Harris <cfharris@...>
 

IPA is so miscible in water that water works just fine for putting
it out. The water dilutes it to a point where it will no longer burn.
A shower is better than a stream as it dilutes and cools the IPA without
spreading it around.

If you blast IPA with a stream of water, it will splash the alcohol
before it dilutes it enough to render it nonflammable.

The MSDS for IPA says use water.

Where water gets you in trouble is nonpolar solvents like gasoline,
kerosene, etc. The solvent is lighter than water, and flaming solvent
floats on the surface of the water spreading the fire.

-Chuck Harris

Gary Robert Bosworth wrote:

I use Isopropyl alcohol for many cleaning jobs - especially solder flux.
Just don't let it get near a source of ignition. It is almost completely
invisible when lit, and requires a specific type of fire extinguisher to
put it out. The fire can spread very quickly as the liquid is as thin as
water and will run all over the place.

Gary


Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

Gary Robert Bosworth
 

I use Isopropyl alcohol for many cleaning jobs - especially solder flux.
Just don't let it get near a source of ignition. It is almost completely
invisible when lit, and requires a specific type of fire extinguisher to
put it out. The fire can spread very quickly as the liquid is as thin as
water and will run all over the place.

Gary


On Wed, Mar 6, 2019 at 1:10 PM Bob Albert via Groups.Io <bob91343=
yahoo.com@groups.io> wrote:

It looks like the link has been filtered out. Just google the title.
Bob
On Wednesday, March 6, 2019, 11:55:07 AM PST, Bob Albert via Groups.Io
<bob91343=yahoo.com@groups.io> wrote:

For the general information of the group, here is a link to determine
characteristics of various solvents, etc. It provides more information
than you will ever want to have.
The Most Complete Free Material Safety Data Sheet (MSDS) list of chemical
information on the Internet


|
|
|
| | |

|

|
|
| |
The Most Complete Free Material Safety Data Sheet (MSDS) list of chemica...

Looking for MSDS information regarding the chemicals in a commercial
product or a material safety data sheet (MS...
|

|

|




On Wednesday, March 6, 2019, 11:16:45 AM PST, Roy Thistle <
roy.thistle@mail.utoronto.ca> wrote:

Hi:
Lots of companies sell it. I see it on Amazon for 13.00 U.S. a gallon (4,
1 quart plastic bottles.) It is very hydroscopic (absorbs water from the
air readily)… so unless you store it over a drying agent, it will tend
towards 90%, as it picks up water, from the air that gets into the bottle.
The main advantage of IPA is it is cheap (really cheap compared to
proprietary cleaners, like Deoxit). But, another significant advantage is
that it is a pure (other than the little bit of water)… it is a pure
chemical. So, you know what you are using, and can find out what it will do
to what you are using it on (That part needs some research, or advice.).
You can get (download) the Material Safety Data Sheet (MSDS), so you can
determine how it will affect you, how to use it safely, and how it will
affect the environment. The MSDS for many proprietary cleaners don't
significantly identify what's in them (it's proprietary).
Regards







--
Gary Robert Bosworth
grbosworth@gmail.com
Tel: 310-317-2247


Re: TEST MESAGE. "Fw: You have been removed from TekScopes@groups.io"

Kyle Rhodes
 

Agreed Dave. I was surprised to see so many people still use Thunderbird, Eudora, and the like, complaining of attachments, etc.

I’ve been on Gmail since it was launched and I’ve never looked back. It also automagically threads conversations so there aren’t any concerns of who said what with the various complaints I see of people not quoting replies properly....

My $0.02 — everyone should at least try it.

On Mar 6, 2019, at 9:24 PM, David Kuhn <Daveyk021@gmail.com> wrote:

Daniel, I recommend GMAIL. It automatically sorts this forum in to a
"forums" TAB.

Dave

On Wed, Mar 6, 2019 at 1:09 PM Daniel Koller via Groups.Io <kaboomdk=
yahoo.com@groups.io> wrote:

Hi Folks,
This is a test for me to make sure I am re-subscribed, and a warning
to others to be careful.
I use Yahoo mail to read my tekscopes group messages (perhaps I should
not use Yahoo Mail). This morning I *accidentally* clicked on a message
and reported it as spam, then immediately restored it to my inbox realizing
it was the wrong one. It seems groups.io is on a hair trigger because it
sent me the message below. This must be a new setting because...
...I have accidentally reported messages from Tekscopes as spam before,
and this has not happened, and some Tekscopes messages regularly end up in
my spam folder anyway, and I have to check there from time to time. So,
wonder if Yahoo is now reporting when you move a message to spam, or
groups.io is now recording when yahoo sends such a report.
Either way, heads up to everyone that the system is sensitive!
Dennis, is there a way to set up the groups.io system so that it takes
3 or so reports of spam before groups.io unsubscribes a user? Thanks,
Dan


----- Forwarded Message ----- From: TekScopes@groups.io <
TekScopes+owner@groups.io>To: "kaboomdk@yahoo.com" <kaboomdk@yahoo.com>Sent:
Wednesday, March 6, 2019, 10:23:58 AM ESTSubject: You have been removed
from TekScopes@groups.io
Hello,
Because your Email Service Provider reported to us that one or more
messages sent to you from TekScopes@groups.io has been marked as spam you
have been automatically removed from the group. We suggest that you check
your spam box as soon as possible to see if your Email Service Provider has
diverted legitimate messages into it.

You will receive no more emails from that group. If this was a mistake,
you can resume your subscription within the next 7 days by clicking the
following link:

Resume Subscription

Groups.io groups offer several options for controlling how much and what
types of emails to receive. See this Help Center article for more
information.

If this happens repeatedly please check with your email service to learn
about how they decide to send feedback reports to list services (such as
Groups.io groups).

Cheers,
The Groups.io Team






Re: TEST MESAGE. "Fw: You have been removed from TekScopes@groups.io"

David Kuhn
 

Daniel, I recommend GMAIL. It automatically sorts this forum in to a
"forums" TAB.

Dave

On Wed, Mar 6, 2019 at 1:09 PM Daniel Koller via Groups.Io <kaboomdk=
yahoo.com@groups.io> wrote:

Hi Folks,
This is a test for me to make sure I am re-subscribed, and a warning
to others to be careful.
I use Yahoo mail to read my tekscopes group messages (perhaps I should
not use Yahoo Mail). This morning I *accidentally* clicked on a message
and reported it as spam, then immediately restored it to my inbox realizing
it was the wrong one. It seems groups.io is on a hair trigger because it
sent me the message below. This must be a new setting because...
...I have accidentally reported messages from Tekscopes as spam before,
and this has not happened, and some Tekscopes messages regularly end up in
my spam folder anyway, and I have to check there from time to time. So,
wonder if Yahoo is now reporting when you move a message to spam, or
groups.io is now recording when yahoo sends such a report.
Either way, heads up to everyone that the system is sensitive!
Dennis, is there a way to set up the groups.io system so that it takes
3 or so reports of spam before groups.io unsubscribes a user? Thanks,
Dan


----- Forwarded Message ----- From: TekScopes@groups.io <
TekScopes+owner@groups.io>To: "kaboomdk@yahoo.com" <kaboomdk@yahoo.com>Sent:
Wednesday, March 6, 2019, 10:23:58 AM ESTSubject: You have been removed
from TekScopes@groups.io
Hello,
Because your Email Service Provider reported to us that one or more
messages sent to you from TekScopes@groups.io has been marked as spam you
have been automatically removed from the group. We suggest that you check
your spam box as soon as possible to see if your Email Service Provider has
diverted legitimate messages into it.

You will receive no more emails from that group. If this was a mistake,
you can resume your subscription within the next 7 days by clicking the
following link:

Resume Subscription

Groups.io groups offer several options for controlling how much and what
types of emails to receive. See this Help Center article for more
information.

If this happens repeatedly please check with your email service to learn
about how they decide to send feedback reports to list services (such as
Groups.io groups).

Cheers,
The Groups.io Team





Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

Brad Thompson
 

Hello--


I use 190-proof straight ethyl alcohol (*) to remove rosin flux and clean PC boards.
Pour a little at a time into a working container and promptly close the original
 bottle to minimize absorption of moisture from the air.

(Having experienced a chemically-induced anaphylactic-shock episode,
I'm careful about what I use for cleaners and lubricants.)

73--

Brad  AA1IP

(*) Everclear is one brand-- a fifth (750 mL) lasts a long time.

And no, I never drink the stuff<g>.


Re: Tektronix Rescue Mission

 

PMI1038 systems

these are GREAT scalar analyzers. they support both analog and digital displays (good for slow sweep speeds).  they require a sweep ramp signal input from a microwave sweeper (hp 8620C, etc.)
and at least one sensor in the V plug in slot. there are usually 2 verticals, so you can display
two signals, like forward and reflected power, etc.

the pull out tray usually stores the sensors.  you can test them with the cal output,
and the INT horizontal sweep position, should give a flat line on the CRT for each channel at the cal level.
I keep some operating info on them here:
https://www.sphere.bc.ca/test/rf-analyzers.html

I have a lot of info on these, as I use them all the time. please contact me directly for more
once you have them in hand.  we will have a complete 1038 system with dual sensors for just C$250, and a pile of PMI/Wavetek sensors at Stuff Day!   https://www.sphere.bc.ca/test/stuffday.html

all the best,
walter--

Walter Shawlee 2
Sphere Research Corp. 3394 Sunnyside Rd.
West Kelowna, BC, V1Z 2V4 CANADA
Phone: +1 (250-769-1834 -:- http://www.sphere.bc.ca
+We're all in one boat, no matter how it looks to you. (WS2)
+All you need is love. (John Lennon)
+But, that doesn't mean other things don't come in handy. (WS2)
+Nature is trying very hard to make us succeed, but nature does not depend on us.
We are not the only experiment. (R. Buckminster Fuller)


Re: Tektronix Rescue Mission

nonIonizing EMF
 

On Wed, Mar 6, 2019 at 04:07 PM, nonIonizing EMF wrote:


https://corvallis.craigslist.org/ …/corvalli…/6833376214.html
Here's the link that posted strange with that account: https://corvallis.craigslist.org/ele/d/corvallis-tektronix-oscilloscope/6833376214.html


Tektronix Rescue Mission

nonIonizing EMF
 

Some Tektronix Equipment areas of opportunity to rescue:
https://corvallis.craigslist.org/…/corvalli…/6833376214.html

I'm not going to be eating much this month. I invested in the Wavetek and Pacific Instruments 1038 (Tektronix 5000 series looks like compatibility) kits. They're spoken for or in route. I think the rest are available.

Also, if anyone has any feedback regarding the Wavetek and Pacific Instruments 1038 systems I'd appreciate any suggestions, comments, thoughts, etc. regarding since there isn't much on the web relating to? Thanks in advance!


Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

Bill Carns
 

Yes, WD-40 is dangerous stuff when used inappropriately. IT IS DEFINITELY
not a lubricant. It is for water displacement as you say. If you use it on
steel stuff, after it has done its freeing up or water lifting job, get it
all off. Use another cleaner like Brake cleaner or one of the good
electronic cleaners and then use oil if you need to lubricate.

I saw a nasty demonstration one time. A guy in California took two raw
steel plates - like maybe a drill press table of something un-plated, and he
sprayed one with WD-40 and left the other alone. Then he went away for 6
months and left them out in the weather. The WD-40 kept doing its job
alright. It kept attracting water and the plate with WD-40 rusted as bad as
they come.

Never ever leave it on steel.

I use it occasionally (and yes, it is GREAT at getting seized older pot
bushings going again) but I also know when NOT to use it - I hope.

Bill

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Craig
Sawyers
Sent: Wednesday, March 06, 2019 4:29 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] 91% Isopropyl Rubbing Alcohol to clean
potentiometers?

WD40 is a different thing. I think it is mostly a water displacement
compound... and, it is very good at that... for driving water, or
moisture, out of closely fitting parts. It does clean, or dissolve
too. And it will lubricate (at least temporarily... the liquid
lubricant (low viscosity petroleum distillates and very fine mineral
oil?) evaporates fairly quickly, and leaves a white residue (not sure
if the white stuff has lubrication properties.) I have used it to free
really stuck potentiometer shafts, where they pass through the
bushing... the WD40 runs easily into the busing, and some mechanical
force frees up the shaft. I don't like to use penetrating oil. It is
kind of a last ditch thing to try, if other methods fail to unseize
the shaft... and sometimes nothing seems to work too.
There is a subculture of old Teleprinter collectors who have nothing good to
say about WD40. If you use it to lubricate one of those supremely intricate
mechanisms, it dissolves all the old gummy grease and deposits it in the
moving parts. Which totally seizes the mechanism.

The only solution is to totally strip the many hundreds of parts in the
machine, clean every part and reassemble with correct lubricants.

Craig


Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

 

Quite right. It isn’t a lubricant, it’s a water dispersant and nothing else - the key is in the WD! Water Dispersant No. 40.

Robin

On 6 Mar 2019, at 22:29, Craig Sawyers <c.sawyers@tech-enterprise.com> wrote:

WD40 is a different thing. I think it is mostly a water displacement compound... and, it is very
good at
that... for driving water, or moisture, out of closely fitting parts. It does clean, or dissolve
too. And it
will lubricate (at least temporarily... the liquid lubricant (low viscosity petroleum distillates
and very
fine mineral oil?) evaporates fairly quickly, and leaves a white residue (not sure if the white
stuff has
lubrication properties.) I have used it to free really stuck potentiometer shafts, where they pass
through the bushing... the WD40 runs easily into the busing, and some mechanical force frees up the
shaft. I don't like to use penetrating oil. It is kind of a last ditch thing to try, if other
methods fail to
unseize the shaft... and sometimes nothing seems to work too.
There is a subculture of old Teleprinter collectors who have nothing good to say about WD40. If you
use it to lubricate one of those supremely intricate mechanisms, it dissolves all the old gummy grease
and deposits it in the moving parts. Which totally seizes the mechanism.

The only solution is to totally strip the many hundreds of parts in the machine, clean every part and
reassemble with correct lubricants.

Craig





Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

Craig Sawyers <c.sawyers@...>
 

WD40 is a different thing. I think it is mostly a water displacement compound... and, it is very
good at
that... for driving water, or moisture, out of closely fitting parts. It does clean, or dissolve
too. And it
will lubricate (at least temporarily... the liquid lubricant (low viscosity petroleum distillates
and very
fine mineral oil?) evaporates fairly quickly, and leaves a white residue (not sure if the white
stuff has
lubrication properties.) I have used it to free really stuck potentiometer shafts, where they pass
through the bushing... the WD40 runs easily into the busing, and some mechanical force frees up the
shaft. I don't like to use penetrating oil. It is kind of a last ditch thing to try, if other
methods fail to
unseize the shaft... and sometimes nothing seems to work too.
There is a subculture of old Teleprinter collectors who have nothing good to say about WD40. If you
use it to lubricate one of those supremely intricate mechanisms, it dissolves all the old gummy grease
and deposits it in the moving parts. Which totally seizes the mechanism.

The only solution is to totally strip the many hundreds of parts in the machine, clean every part and
reassemble with correct lubricants.

Craig


Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

David Slipper
 

IPA make a great paint remover
It sure does - dont spill any on your Tek scope case --- the blue paint
becomes "tacky" as a friend found out while cleaning his.
I ended up respraying it for him :-(

Dave


Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

David Slipper
 

Very interesting ... the book is available as PDF FYI

There is also a "trimmer primer" which I found interesting.

Dave

On 06/03/2019 22:03, Roy Thistle wrote:
Hi All:
There are three kinds of pots in common use, that I remember about: these are wire wound, carbon film, and plastic film. Also, there are ceramic film pots now too. I think many of us are familiar with the sound and feel of wire wound pots. The de-greasing, deoxidizing, anti-oxidizing, and lubricating properties of "cleaners" such as they are assumed to be... or claimed to be... seem to make sense to me, for wire wound pots. For carbon film, and plastic film.... and probably ceramic film... I think de-greasing, and lubrication makes sense.
Many of the pots, in the parts lists, of some Tek scopes, are specified as being manufactured by Bournes. If anyone is interested, Bournes publishes a book "The Potentiometer Handbook" in the 1970's... which is 50 years ago... but, I don't think the technology of electro-mechanical pots (like those used in old Tek scopes) has changed that much... except, I don't think they had ceramic film pots... and the build quality was much better? Anyway, pots are interesting... there are linear, log, trig, and multi-turn, as least... and the Bournes book is comprehensive.
Regards.



.


Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

Roy Thistle
 

Hi All:
There are three kinds of pots in common use, that I remember about: these are wire wound, carbon film, and plastic film. Also, there are ceramic film pots now too. I think many of us are familiar with the sound and feel of wire wound pots. The de-greasing, deoxidizing, anti-oxidizing, and lubricating properties of "cleaners" such as they are assumed to be... or claimed to be... seem to make sense to me, for wire wound pots. For carbon film, and plastic film.... and probably ceramic film... I think de-greasing, and lubrication makes sense.
Many of the pots, in the parts lists, of some Tek scopes, are specified as being manufactured by Bournes. If anyone is interested, Bournes publishes a book "The Potentiometer Handbook" in the 1970's... which is 50 years ago... but, I don't think the technology of electro-mechanical pots (like those used in old Tek scopes) has changed that much... except, I don't think they had ceramic film pots... and the build quality was much better? Anyway, pots are interesting... there are linear, log, trig, and multi-turn, as least... and the Bournes book is comprehensive.
Regards.


Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

Bill Carns
 

Just so everyone knows:

This the understatement of the year.

"IPA is, to some extent, going to attack natural shellacs, varnishes, and lacquers (IPA might be similar to the solvents they use.). So caution might be advisable with old electronics,"

IPA make a great paint remover

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Roy Thistle
Sent: Wednesday, March 06, 2019 3:17 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] 91% Isopropyl Rubbing Alcohol to clean potentiometers?

Hi:
I think that high concentration IPA might... but only after prolonged contact (like soaking a part in it, in a closed container) partly dissolve some of the binders, or plasticizers, in rubber or plastic parts (Some of those are to a degree soluble in IPA.) . IPA is, to some extent, going to attack natural shellacs, varnishes, and lacquers (IPA might be similar to the solvents they use.). So caution might be advisable with old electronics, that might have used these in their manufacture.

Most of the chemicals that Bob mentions are de-greasers. As Bob points out acetone (in some nail polish removers) is a strong degreaser (Usually used on bare metal because it can dissolve, or weaken, some plastics, and paints.) Of all the strong degreasers Bob mentions, acetone is available, and is not very toxic (though good ventilation is necessary, and no sparks or flames).

There are also chemicals that are de-oxidizers, anti-oxidants, and lubricants (usually just being one of those kinds of things.) Some "cleaners" claim to be all those things. In other threads there were discussions about the different kinds of Deoxit, for sale. I don't use it. And, I don't know about it. So, I am not saying it works, or it doesn't... I don't know. But, I am listening and researching. The main things that turn me away from "cleaners" is I don't usually know what is in them (So, I don't know what I am using.) That and, the amount of woo around them. They are expensive too. And some of that might be just because people might not know how cheap and available, the chemicals that they use, are (because we don't know what is in them.)

WD40 is a different thing. I think it is mostly a water displacement compound... and, it is very good at that... for driving water, or moisture, out of closely fitting parts. It does clean, or dissolve too. And it will lubricate (at least temporarily... the liquid lubricant (low viscosity petroleum distillates and very fine mineral oil?) evaporates fairly quickly, and leaves a white residue (not sure if the white stuff has lubrication properties.) I have used it to free really stuck potentiometer shafts, where they pass through the bushing... the WD40 runs easily into the busing, and some mechanical force frees up the shaft. I don't like to use penetrating oil. It is kind of a last ditch thing to try, if other methods fail to unseize the shaft... and sometimes nothing seems to work too.

As Bob mentions.... I've had good success with "exercising" a "scratchy" pot too.
Regards


Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

Roy Thistle
 

Hi:
I think that high concentration IPA might... but only after prolonged contact (like soaking a part in it, in a closed container) partly dissolve some of the binders, or plasticizers, in rubber or plastic parts (Some of those are to a degree soluble in IPA.) . IPA is, to some extent, going to attack natural shellacs, varnishes, and lacquers (IPA might be similar to the solvents they use.). So caution might be advisable with old electronics, that might have used these in their manufacture.

Most of the chemicals that Bob mentions are de-greasers. As Bob points out acetone (in some nail polish removers) is a strong degreaser (Usually used on bare metal because it can dissolve, or weaken, some plastics, and paints.) Of all the strong degreasers Bob mentions, acetone is available, and is not very toxic (though good ventilation is necessary, and no sparks or flames).

There are also chemicals that are de-oxidizers, anti-oxidants, and lubricants (usually just being one of those kinds of things.) Some "cleaners" claim to be all those things. In other threads there were discussions about the different kinds of Deoxit, for sale. I don't use it. And, I don't know about it. So, I am not saying it works, or it doesn't... I don't know. But, I am listening and researching. The main things that turn me away from "cleaners" is I don't usually know what is in them (So, I don't know what I am using.) That and, the amount of woo around them. They are expensive too. And some of that might be just because people might not know how cheap and available, the chemicals that they use, are (because we don't know what is in them.)

WD40 is a different thing. I think it is mostly a water displacement compound... and, it is very good at that... for driving water, or moisture, out of closely fitting parts. It does clean, or dissolve too. And it will lubricate (at least temporarily... the liquid lubricant (low viscosity petroleum distillates and very fine mineral oil?) evaporates fairly quickly, and leaves a white residue (not sure if the white stuff has lubrication properties.) I have used it to free really stuck potentiometer shafts, where they pass through the bushing... the WD40 runs easily into the busing, and some mechanical force frees up the shaft. I don't like to use penetrating oil. It is kind of a last ditch thing to try, if other methods fail to unseize the shaft... and sometimes nothing seems to work too.

As Bob mentions.... I've had good success with "exercising" a "scratchy" pot too.
Regards


Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?

Bob Albert
 

It looks like the link has been filtered out.  Just google the title.
Bob

On Wednesday, March 6, 2019, 11:55:07 AM PST, Bob Albert via Groups.Io <bob91343=yahoo.com@groups.io> wrote:

For the general information of the group, here is a link to determine characteristics of various solvents, etc.  It provides more information than you will ever want to have.
The Most Complete Free Material Safety Data Sheet (MSDS) list of chemical information on the Internet


|
|
|
|  |  |

|

|
|
|  |
The Most Complete Free Material Safety Data Sheet (MSDS) list of chemica...

Looking for MSDS information regarding the chemicals in a commercial product or a material safety data sheet (MS...
|

|

|




    On Wednesday, March 6, 2019, 11:16:45 AM PST, Roy Thistle <roy.thistle@mail.utoronto.ca> wrote:

Hi:
Lots of companies sell it. I see it on Amazon for 13.00 U.S. a gallon (4, 1 quart plastic bottles.) It is very hydroscopic (absorbs water from the air readily)… so unless you store it over a drying agent, it will tend towards 90%, as it picks up water, from the air that gets into the bottle.
The main advantage of IPA is it is cheap (really cheap compared to proprietary cleaners, like Deoxit). But, another significant advantage is that it is a pure (other than the little bit of water)… it is a pure chemical. So, you know what you are using, and can find out what it will do to what you are using it on (That part needs some research, or advice.). You can get (download) the Material Safety Data Sheet (MSDS), so you can determine how it will affect you, how to use it safely, and how it will affect the environment. The MSDS for many proprietary cleaners don't significantly identify what's in them (it's proprietary).
Regards


Re: 7834 with bad HV transformer free to good home

 

Sorry, Craig Sawyers got there first!

David

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Roger Evans via Groups.Io
Sent: 06 March 2019 20:37
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7834 with bad HV transformer free to good home

David,

I have a 7934 which is in good health apart from some damage to the storage meshes at the front of the CRT, works fine in non-storage mode. I have been hoping for some time to find a good CRT from a 7834 or 7934 as a replacement. I would be delighted to come and collect. You can contact me at r.g.evans@talk21.com to minimise clutter on the list.

Many thanks,

Roger Evans

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