1. TekScopes@groups.io
   Date   
Re: Is an early 7A26 a keeper?

John
 

Ron, that is what I figure too. U1350 is the probable culprit as the signals match on channel 1 & 2 up to that point. The readout is OK so it is basically in the gain channel. As I say one day;-))

John Proctor
VK2DLP
Re: non-gumming oil

Ken Eckert
 

It really works well in the task removing label glue. Paper labels I just
let it soak into the label, let it sit and pell off the label, remove the
glue then your favourite IPA to remove the WD-40. One thing about WD-40 I
have not found a material that it "attacks"

Ken

On Wed, Aug 14, 2019 at 1:36 PM greenboxmaven via Groups.Io <ka2ivy=
verizon.net@groups.io> wrote:

I have seen some lively discussions about WD-40 in switches, pots and
bearings. I have never had any problem using it as a PART of the
cleaning process. It will often cut loose crud that nothing else will,
but must be completely flushed out once it has done it's job or it will
soon become a residue far worse than the original.

Bruce Gentry, KA2IVY


On 8/14/19 1:09 PM, Greg Muir via Groups.Io wrote:
WD-40

Spent a couple of years working in the tropics with extremely high
humidity. I used to protect tools from rusting by wiping them with WD-40
then storing unused tools in plastic bags. What I found after coming back
after several months to use them was that the light hydrocarbons used in
the product had evaporated leaving behind a petroleum based product with
the consistency of something between 90 weight oil and Cosmoline.

From this I learned that it is only good for a very few purposes (aside
from the original intent of the product for coating the outsides of
missiles to prevent corrosion) is to protect items from rust and corrosion
(with some subsequent clean-up effort), a penetrent and, on occasion, a
gummed label remover. When I hear of someone using it to lubricate
potentiometers, switches and such, I wince.

A footnote: while at the project it was interesting to find that all of
the local outlets sold WD-40 in gallon cans, an indication that I was
probably not the only one facing rust and corrosion issues.

Greg
Re: non-gumming oil

greenboxmaven
 

I have seen some lively discussions about WD-40 in switches, pots and bearings. I have never had any problem using it as a PART of the cleaning process. It will often cut loose crud that nothing else will, but must be completely flushed out once it has done it's job or it will soon become a residue far worse than the original.

Bruce Gentry, KA2IVY

On 8/14/19 1:09 PM, Greg Muir via Groups.Io wrote:
WD-40

Spent a couple of years working in the tropics with extremely high humidity. I used to protect tools from rusting by wiping them with WD-40 then storing unused tools in plastic bags. What I found after coming back after several months to use them was that the light hydrocarbons used in the product had evaporated leaving behind a petroleum based product with the consistency of something between 90 weight oil and Cosmoline.

From this I learned that it is only good for a very few purposes (aside from the original intent of the product for coating the outsides of missiles to prevent corrosion) is to protect items from rust and corrosion (with some subsequent clean-up effort), a penetrent and, on occasion, a gummed label remover. When I hear of someone using it to lubricate potentiometers, switches and such, I wince.
A footnote: while at the project it was interesting to find that all of the local outlets sold WD-40 in gallon cans, an indication that I was probably not the only one facing rust and corrosion issues.

Greg
Re: non-gumming oil

Chuck Harris
 

Hi Richard,

I tend to use Oilite as a generic term for sintered bronze.
It seems to be a common usage among older mechanics and
machinists... Oilite kind of rolls off the tongue better than
sintered bronze.

I am pretty sure that Oilite didn't invent sintered bronze, but
rather were the first to market oil infused sintered bronze, and
claim it was a lifetime lubricated bearing... it most certainly
isn't... unless you gauge lifetime to be the devices working
life.

I am certain that you are right, Oilite is a pre-oiled product,
and in light duty, slow speed applications it is used that way
quite often... A turntable fits that description.

However, in higher speed, heavier duty applications it is all
but unheard of to use it that way. Things like blowers that
need to be quieter than ball bearing will allow, furnace blowers,
bathroom ventilation fans, ... Tektronix 500 series scope fans...
In these sorts of applications, an oil reservoir is used. It
may be only filled by the motor's manufacturer, but it is a
reservoir none the less.

Turbine oil has a slightly more noble purpose, being intended
for pressurized lubrication systems in jet engines... but that
is exactly the same sort of bearing as is serviced by automotive
motor oil. Turbocharged engines have turbines that spin faster
than 100KRPM, and use a synthetic motor oil, such as mobil 1.

Turbine oil, and light weight motor oil work equally well for
these lowly light duty motors.

I have both on my bench, and which I use is more dependent on
which container will fit the motor I am oiling.

My 5W30 synthetic motor oil has a 16ga blunt needle, and the
turbine oil has a 6" long 3/16" wide straw...

...Very scientific!...

-Chuck Harris

Richard Knoppow wrote:

Look at the Oilite web site. They state that the oil is infused via vacuum. This
is what I always understood about how Oilite bearings were made. There are sintered
bearings that are meant for an external oil reservoir but the Oilite type is
lubricated during manufacture and is not supposed to need any other lubrication
although the web site describes the use of a light wax to eliminate break-in.
In the past I was involved in rebuilding sound recording equipment with Oilite
bearings. They were not easily replacable. I used turbine oil of a type recommended
by the lab of one of the larger oil companies. He gave us a sample, about a quart, I
never used it up. Turbine oil is a very highly refined oil.
Re: Is an early 7A26 a keeper?

ron roetzer
 

Dennis
I should have been more precise, I didn't mean to imply that the 7A26 had differential inputs but that the internal signal path was differential. If you look at the block diagram in section 7 of the manual the signal becomes differential after U1350 (U2350) and continues differentially to the vertical signal output. If either side of the differential pair is not functioning then the output would be 1/2.

Ron

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Dennis Tillman W7PF
Sent: Wednesday, August 14, 2019 2:43 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Is an early 7A26 a keeper?

Hi Ron,
This is not what is causing the 1/2 gain in one of the two channels but not the other. The 7A26 is not differential. It has two separate input channels.

In certain cases the 2nd channel can be inverted and added to the first channel to make a "primitive" difference, but not differential, amplifier. Tek generally makes no claims about the performance of their vertical amplifiers when the signal goes off screen. While the signal is on-screen it is in the linear region of the vertical amplifier and you can expect the bandwidth of the amplifier will meet its stated specs.

Provided neither signal by itself goes off screen, and the addition of both signals stays on screen, you will probably remain in the linear region of both channels. If you invert Ch 2 and add both signals together you will get the difference between them provided you use the same probes on each channel and you are careful to calibrate their response as closely as possible. You will also need to calibrate the gain of each channel.

Even if you did all this it would be misleading to assume that the on screen result was what a true differential amplifier with matched probes, matched inputs, matched phase response, matched offsets, etc would give you.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of ron_roetzer@comcast.net
Sent: Wednesday, August 14, 2019 5:42 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Is an early 7A26 a keeper?

although I have no specific knowledge of the 7A26, in differential amplifiers if one side is dead then the gain is exactly 1/2 what it should be.





--
Dennis Tillman W7PF
TekScopes Moderator
Re: 2440 deal

Bob Albert
 

Wow good news!  I hope one of those will end up here.  Keep me informed.
Bob818 894-2887

On Wednesday, August 14, 2019, 09:29:00 AM PDT, Robert Simpson via Groups.Io <go_boating_fast=yahoo.com@groups.io> wrote:

Snagged two, one already gone. Got a reply from seller and my daughter was able to pick up two. I will get to see them next time she comes up (from SF South bay area). Was excess inventory from the seller's company.
Bob
Re: Is an early 7A26 a keeper?

Dennis Tillman W7pF
 

Hi Ron,
This is not what is causing the 1/2 gain in one of the two channels but not the other. The 7A26 is not differential. It has two separate input channels.

In certain cases the 2nd channel can be inverted and added to the first channel to make a "primitive" difference, but not differential, amplifier. Tek generally makes no claims about the performance of their vertical amplifiers when the signal goes off screen. While the signal is on-screen it is in the linear region of the vertical amplifier and you can expect the bandwidth of the amplifier will meet its stated specs.

Provided neither signal by itself goes off screen, and the addition of both signals stays on screen, you will probably remain in the linear region of both channels. If you invert Ch 2 and add both signals together you will get the difference between them provided you use the same probes on each channel and you are careful to calibrate their response as closely as possible. You will also need to calibrate the gain of each channel.

Even if you did all this it would be misleading to assume that the on screen result was what a true differential amplifier with matched probes, matched inputs, matched phase response, matched offsets, etc would give you.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of ron_roetzer@comcast.net
Sent: Wednesday, August 14, 2019 5:42 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Is an early 7A26 a keeper?

although I have no specific knowledge of the 7A26, in differential amplifiers if one side is dead then the gain is exactly 1/2 what it should be.





--
Dennis Tillman W7PF
TekScopes Moderator
Re: 5xx 'Scopes

Dennis Tillman W7pF
 

EVERY Tek curve tracer, except for the limited plugin versions (7CT1N and 5CT1N) have two "sockets" to do A/B comparisons. This includes the 570 (vacuum tube curve tracer), 575, 576, 577, and 370. The 576 and the 577 have similar basic capabilities such as their maximum voltage (1,600V at 100mA, and 1,500V at 200mA respectively), but differ significantly in other ways.

The 576 has an optional 176 high current "front porch" capable of testing power transistors. The 576 has readouts (not on-screen) which assist casual users in avoiding mistakes when making basic device measurements.

The 577 comes in a non-storage (577-D2) and storage 577-(D1) CRT version. It has an optional 176 "front porch" which can test single, dual, or quad OpAmps, SCRs, 3 Terminal Positive and Negative Voltage Regulators.

Both the 576 and the 577 were designed to make the majority of semiconductor measurements that any circuit designer would be interested in quantifying. I once asked Deane Kidd, when I was in his lab, which he recommended, 576 or 577. His answer was definitive: the 577 hands down. So that is what I found to replace my 575 10 years ago. I have had both the 577-D2 and 577-D1 over the years since and there is no question that the 577-D1 (storage) version has more capabilities although the storage is tricky to adjust and is sometimes annoying.

I am now fortunate to own both a 576 and a 577 and all the optional "front porches" so I can test just about anything.

Sean: I believe you are thinking of the low cost adapter board I designed to test vacuum tubes on a Tek semiconductor curve tracer. My adapter is not limited to the 576. It works on ANY Tek curve tracer (575, 576, 577, 7CT1N, and 5CT1N). Contact me OFF-LIST at "dennis at ridesoft dot com" if you would like a copy of the paper I wrote about testing vacuum tubes on Tek curve tracers.

Dennis Tillman W7PF

-----Original Message-----
From: Chuck Harris
Sent: Wednesday, August 14, 2019 5:17 AM

I would have to beg to differ, the 577 has the same left/right sockets, left/right lever switch, and as such, comparison capability as the 576.
It even uses the same dual transistor plugin adapters.
It (with the right option) even has a split screen storage capability.
What it doesn't have is any form of on screen readout display of the settings.

-Chuck Harris

sdturne@q.com wrote:
On Tue, Aug 13, 2019 at 07:59 AM, Mlynch001 wrote:

One of the best finds of mine was a very nice Type 576 Curve Tracer
(at a great price). The 576 has indeed helped me repair other
equipment. More importantly, it has greatly increased my
understanding of all these little pieces of black plastic with various wires protruding from the sides.

Michael Lynch
Dardanelle, AR
That's exactly the model I would like to find. The 577 is smaller but lacks the ability to do A-B comparison testing. The 576 can do vacuum tubes too, with the right test fixture if I'm not mistaken.

Sean



--
Dennis Tillman W7PF
TekScopes Moderator
Re: non-gumming oil

Richard Knoppow
 

Look at the Oilite web site. They state that the oil is infused via vacuum. This is what I always understood about how Oilite bearings were made. There are sintered bearings that are meant for an external oil reservoir but the Oilite type is lubricated during manufacture and is not supposed to need any other lubrication although the web site describes the use of a light wax to eliminate break-in.
In the past I was involved in rebuilding sound recording equipment with Oilite bearings. They were not easily replacable. I used turbine oil of a type recommended by the lab of one of the larger oil companies. He gave us a sample, about a quart, I never used it up. Turbine oil is a very highly refined oil.

On 8/14/2019 10:45 AM, Stephen Hanselman wrote:
Sorry Chuck,
My only experience with these type of bearings is with ones that were already oiled, sorry about that. One thing I like about this list is the plethora of new information.
Steve
--
Richard Knoppow
dickburk@ix.netcom.com
WB6KBL
Re: non-gumming oil

Stephen Hanselman
 

You're right it was, I saw this on a Science channel show.

S

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Jim Ford
Sent: Wednesday, August 14, 2019 10:41 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] non-gumming oil

The WD stands for Water Displacing, by the way. 40 is presumably because it was the 40th substance the manufacturer tried.Jim FordSent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: "Greg Muir via Groups.Io" <big_sky_explorer=yahoo.com@groups.io> Date: 8/14/19 10:09 AM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] non-gumming oil WD-40Spent a couple of years working in the tropics with extremely high humidity. I used to protect tools from rusting by wiping them with WD-40 then storing unused tools in plastic bags. What I found after coming back after several months to use them was that the light hydrocarbons used in the product had evaporated leaving behind a petroleum based product with the consistency of something between 90 weight oil and Cosmoline.From this I learned that it is only good for a very few purposes (aside from the original intent of the product for coating the outsides of missiles to prevent corrosion) is to protect items from rust and corrosion (with some subsequent clean-up effort), a penetrent and, on occasion, a gummed label remover. When I hear of someone using it to lubricate potentiometers, switches and such, I wince.A footnote: while at the project it was interesting to find that all of the local outlets sold WD-40 in gallon cans, an indication that I was probably not the only one facing rust and corrosion issues.Greg
Re: non-gumming oil

Stephen Hanselman
 

Sorry Chuck,

My only experience with these type of bearings is with ones that were already oiled, sorry about that. One thing I like about this list is the plethora of new information.

Steve

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Chuck Harris
Sent: Wednesday, August 14, 2019 10:39 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] non-gumming oil

Hi Stephen,

I don't recall saying anything about the original infusion with oil. I generally receive sintered bronze bearings that are bone dry from a distributor, such as MSC.

I don't recall ever getting one that was pre-oiled, except perhaps as a bagged replacement part.

I am not sure how the manufacturer of the sintered bronze would know what parameters your oil needed to survive your use.

Oil is not meant to be added to the shaft/oilite interface, it is intended to be done through oil contact with the outer surface of the oilite The oil then diffuses through capillary action into the sintered bronze, just like a common sponge does when it comes into contact with water.

Very few high reliability users of oilite do not provide an oil reservoir... usually in the form of an oil soaked piece of wool felt that is in contact with the oilite. This is what tektronix has in the fan motors for the old vacuum tube scopes. Often, these motors find themselves with their oil holes upside down, so if you find one that way, be kind and restore it to the upright position. Gravity, and all that...

Getting the oil out of, and back into the oilite is easy. To remove it, set it on a rag, and bake it to 212F. As soon as the oilite gets hot, the oil will leave due to expansion. And to put it back, soak it in hot oil, then allow the oil to cool.

Generally, if the bearing isn't worn out, all that is needed is to remove the gummy oil from the outside of the bearing, and shaft, and put some fresh oil in the wool felt.

If you have to keep adding oil to the shaft/oilite interface, to keep the peace, the bearing and shaft are worn out.

-Chuck Harris

Stephen Hanselman wrote:
Chuck,

You’re right on all your points, except the original oiling was when the bearing structure was made and the oil was “infused”(??) into the material (oil-lite bearing)where our added oil is applied to the bearing surface-spindle interface.

Really it gets down to use what works for you. I’ve also had good luck with WD-40 which isn’t ever a lubricant.

Regards,

Stephen Hanselman
Datagate Systems, LLC
3107 North Deer Run Road #24
Carson City, Nevada, 89701
(775) 882-5117 office
(775) 720-6020 mobile
s.hanselman@datagatesystems.com
www.datagatesystems.com
a Service Disabled, Veteran Owned Small Business
DISCLAIMER:
This e-mail and any attachments are intended only for use by the addressee(s) named herein and may contain legally privileged and/or proprietary information. If you are not the intended recipient, any dissemination, distribution or copying of this e-mail and any attachments is strictly prohibited. If you have received this e-mail in error, please immediately notify me and permanently delete the original and all copies and printouts of this e-mail and any attachments.
On Aug 13, 2019, at 14:22, Richard Knoppow <dickburk@ix.netcom.com> wrote:

I am not so sure about what additives there are in engine oil. One can get good quality SAE 20 machine oil at many hardware stores. 3-in-one puts it up in a blue can (red can is something else). Also as Kano Microil, very highly refined petroleum based oil, wax free, and does not gum. Most of these blower bearings are so called "life time lubricated" meaning it works until it doesn't. They are made from sintered bronze with oil held in the spongy metal. You can't really re-lubricate them in any easy way but they will hold oil for a reasonable time.
Hewlett-Packard used blowers with a rubber seal at one end. They could be re-lubricated using a syringe to poke through the seal and inject some oil. I have no idea if the Tek blowers are similar. Unfortunately, once the bearings run dry they will become galled and run rough despite having new lubricant.
I agree with you that mixing silicon oil or grease with petroleum lubricant is not a good idea.

On 8/13/2019 2:03 PM, Chuck Harris wrote:
Why?
Silicone oil isn't miscible with the original oil, and you are not
going to make the motor become maintenance free, no matter what you
do with oils.
Just give it some motor oil, thin like SAE5 or 10 is fine.
Detergent isn't like the stuff you wash your clothes in, it will not
cause any problems, in spite of its suggestive name.
The synthetic doesn't oxidize as quickly as the old oil did, but
then any modern oil is much better in that regard.
The last time anyone lubed your scope fan was likely 40 years ago
and yet, it still works. Give it a couple of drops of oil, and move
on... be happy!
-Chuck Harris
Stephen Hanselman wrote:
I've read some of the answers and wanted to add my two cents. We
use marvel mystery oil which seems ok so far. I was thinking about
using silicon based gun oil though

steve
--
Richard Knoppow
dickburk@ix.netcom.com
WB6KBL
Re: Is an early 7A26 a keeper?

ron roetzer
 

although I have no specific knowledge of the 7A26, in differential amplifiers if one side is dead then the gain is exactly 1/2 what it should be.
Re: non-gumming oil

Jim Ford
 

The WD stands for Water Displacing, by the way.  40 is presumably because it was the 40th substance the manufacturer tried.Jim FordSent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: "Greg Muir via Groups.Io" <big_sky_explorer=yahoo.com@groups.io> Date: 8/14/19 10:09 AM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] non-gumming oil WD-40Spent a couple of years working in the tropics with extremely high humidity.  I used to protect tools from rusting by wiping them with WD-40 then storing unused tools in plastic bags.  What I found after coming back after several months to use them was that the light hydrocarbons used in the product had evaporated leaving behind a petroleum based product with the consistency of something between 90 weight oil and Cosmoline.From this I learned that it is only good for a very few purposes (aside from the original intent of the product for coating the outsides of missiles to prevent corrosion) is to protect items from rust and corrosion (with some subsequent clean-up effort), a penetrent and, on occasion, a gummed label remover.  When I hear of someone using it to lubricate potentiometers, switches and such, I wince.A footnote: while at the project it was interesting to find that all of the local outlets sold WD-40 in gallon cans, an indication that I was probably not the only one facing rust and corrosion issues.Greg
Re: non-gumming oil

Chuck Harris
 

Hi Stephen,

I don't recall saying anything about the original
infusion with oil. I generally receive sintered
bronze bearings that are bone dry from a distributor,
such as MSC.

I don't recall ever getting one that was pre-oiled,
except perhaps as a bagged replacement part.

I am not sure how the manufacturer of the sintered
bronze would know what parameters your oil needed
to survive your use.

Oil is not meant to be added to the shaft/oilite
interface, it is intended to be done through oil
contact with the outer surface of the oilite The
oil then diffuses through capillary action into the
sintered bronze, just like a common sponge does when
it comes into contact with water.

Very few high reliability users of oilite do not
provide an oil reservoir... usually in the form of an
oil soaked piece of wool felt that is in contact with
the oilite. This is what tektronix has in the fan
motors for the old vacuum tube scopes. Often, these
motors find themselves with their oil holes upside down,
so if you find one that way, be kind and restore it to
the upright position. Gravity, and all that...

Getting the oil out of, and back into the oilite is
easy. To remove it, set it on a rag, and bake it to
212F. As soon as the oilite gets hot, the oil will
leave due to expansion. And to put it back, soak it
in hot oil, then allow the oil to cool.

Generally, if the bearing isn't worn out, all that
is needed is to remove the gummy oil from the outside
of the bearing, and shaft, and put some fresh oil in
the wool felt.

If you have to keep adding oil to the shaft/oilite
interface, to keep the peace, the bearing and shaft
are worn out.

-Chuck Harris

Stephen Hanselman wrote:

Chuck,

You’re right on all your points, except the original oiling was when the bearing structure was made and the oil was “infused”(??) into the material (oil-lite bearing)where our added oil is applied to the bearing surface-spindle interface.

Really it gets down to use what works for you. I’ve also had good luck with WD-40 which isn’t ever a lubricant.

Regards,

Stephen Hanselman
Datagate Systems, LLC
3107 North Deer Run Road #24
Carson City, Nevada, 89701
(775) 882-5117 office
(775) 720-6020 mobile
s.hanselman@datagatesystems.com
www.datagatesystems.com
a Service Disabled, Veteran Owned Small Business
DISCLAIMER:
This e-mail and any attachments are intended only for use by the addressee(s) named herein and may contain legally privileged and/or proprietary information. If you are not the intended recipient, any dissemination, distribution or copying of this e-mail and any attachments is strictly prohibited. If you have received this e-mail in error, please immediately notify me and permanently delete the original and all copies and printouts of this e-mail and any attachments.
On Aug 13, 2019, at 14:22, Richard Knoppow <dickburk@ix.netcom.com> wrote:

I am not so sure about what additives there are in engine oil. One can get good quality SAE 20 machine oil at many hardware stores. 3-in-one puts it up in a blue can (red can is something else). Also as Kano Microil, very highly refined petroleum based oil, wax free, and does not gum. Most of these blower bearings are so called "life time lubricated" meaning it works until it doesn't. They are made from sintered bronze with oil held in the spongy metal. You can't really re-lubricate them in any easy way but they will hold oil for a reasonable time.
Hewlett-Packard used blowers with a rubber seal at one end. They could be re-lubricated using a syringe to poke through the seal and inject some oil. I have no idea if the Tek blowers are similar. Unfortunately, once the bearings run dry they will become galled and run rough despite having new lubricant.
I agree with you that mixing silicon oil or grease with petroleum lubricant is not a good idea.

On 8/13/2019 2:03 PM, Chuck Harris wrote:
Why?
Silicone oil isn't miscible with the original oil, and
you are not going to make the motor become maintenance
free, no matter what you do with oils.
Just give it some motor oil, thin like SAE5 or 10 is fine.
Detergent isn't like the stuff you wash your clothes in,
it will not cause any problems, in spite of its suggestive
name.
The synthetic doesn't oxidize as quickly as the old oil
did, but then any modern oil is much better in that regard.
The last time anyone lubed your scope fan was likely 40
years ago and yet, it still works. Give it a couple of
drops of oil, and move on... be happy!
-Chuck Harris
Stephen Hanselman wrote:
I've read some of the answers and wanted to add my two cents. We use marvel
mystery oil which seems ok so far. I was thinking about using silicon based
gun oil though

steve
--
Richard Knoppow
dickburk@ix.netcom.com
WB6KBL
Re: non-gumming oil

Greg Muir
 

WD-40

Spent a couple of years working in the tropics with extremely high humidity. I used to protect tools from rusting by wiping them with WD-40 then storing unused tools in plastic bags. What I found after coming back after several months to use them was that the light hydrocarbons used in the product had evaporated leaving behind a petroleum based product with the consistency of something between 90 weight oil and Cosmoline.

From this I learned that it is only good for a very few purposes (aside from the original intent of the product for coating the outsides of missiles to prevent corrosion) is to protect items from rust and corrosion (with some subsequent clean-up effort), a penetrent and, on occasion, a gummed label remover. When I hear of someone using it to lubricate potentiometers, switches and such, I wince.

A footnote: while at the project it was interesting to find that all of the local outlets sold WD-40 in gallon cans, an indication that I was probably not the only one facing rust and corrosion issues.

Greg
Re: 5xx 'Scopes

Jason A.
 

I have a 535A that I just finished mostly refurbishing I would part with. It's got all new tubes, almost all the capacitors replaced, one broken resistor replaced in the vertical amp, and calibrated up (mostly) to the "B" plugin inside it. I can attest the frequency and voltage displays are in-line with reality, but may need some geometry true-up and probably wouldn't hurt to adjust the delay line. I would also be willing to include a 1A1 plugin (probably needing at minimum new capacitors and a calibration). I am in the Atlanta area. The downside is that with all the parts I've just put into it, I'll have to have what I have sunk into it for acquisition cost and parts. I will even write off the labor as a labor of love keeping something as cool as an old 5-series running.
Re: 2440 deal

Robert Simpson
 

Snagged two, one already gone. Got a reply from seller and my daughter was able to pick up two. I will get to see them next time she comes up (from SF South bay area). Was excess inventory from the seller's company.
Bob
Re: non-gumming oil

Merchison Burke
 

Thank you.

Merchison

On 2019-Aug-13 2:42 PM, greenboxmaven via Groups.Io wrote:
It is a good oil, comparable to the original. It will become rancid in time just as the original did, especially if there is moisture. It is also used in hydraulic elevators as the working oil and as general lube by those working in the craft. It is well refined mineral oil with few or no additives, but I think synthetics are far better.?? I had far better luck with synthetic is fan motors in elevators. I worked in the craft for over 30 years. Most oil distributors have it by the pail, one source for smaller quantities is to befriend an elevator or air conditioning technician. Most appliance supply dealers have it in small squeeze bottles for exorbitant prices.?? NEVER call an elevator company, or worst yet, a supervisor.?? Deal direct with a technician, a cup of coffee or a soda will get you all of the oil you are likely to use for some time!

?????????????????? Bruce Gentry, KA2IVY???? IUEC Local 62, retired


On 8/13/19 2:11 PM, Merchison Burke via Groups.Io wrote:
I was told by an air-conditioner technician that Turbine oil was recommended for use in the small fans used in air-conditioners, being that it is very light.

Can anyone give an opinion about this oil?

Merchison


On 2019-Aug-13 1:43 PM, Stephen Hanselman wrote:
I've read some of the answers and wanted to add my two cents.?? We use marvel
mystery oil which seems ok so far.?? I was thinking about using silicon based
gun oil though

steve

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of John Griessen
Sent: Tuesday, August 13, 2019 8:59 AM
To: TekScopes@groups.io
Subject: [TekScopes] non-gumming oil (was: 547 Fan lubrication) OT

On 8/13/19 10:30 AM, Chuck Harris wrote:
I use mobil 1 5W30... because my car uses it, and I collect the drips
from "empty" bottles.

-Chuck Harris

Morris Odell wrote:
Hi all,

The fan in my 547 was running slow and taking a long time to run up to
speed. I took it apart to find the bearings all gummed up with sticky greasy
old oil. I've washed it all out with an appropriate solvent and now need to
relube it. Is there a recommended oil to use? I have various grades
available ranging from 3-in-1 to heavy EP90.


Do you think synthetic motor oil is as good as Kano Microil non gumming
instrument oil??? I'm getting low on that oil.








---
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Re: non-gumming oil

EricJ
 

I don't think Chuck contradicted that point. Dick described it very well. Oilite bushings are sintered, so they are porous - the number I've seen was about 40% free space - then impregnated with oil. The original process involved pulling a vacuum on the bushings while they were soaked in oil, and then sometimes pressurizing them afterward. I haven't the faintest idea if that's still the process today.

The original Tek bushings could be cleared out by baking at a lower temp so that the oil only evaporates and doesn't burn, then refilling. Pulling a vacuum while in an oil bath would work best but soaking at an elevated temp to thin the oil might be fine. The next question would be whether the bearing surface of the bushing had smeared so that the pores were closed off or not. Probably not I would suspect. This would of course necessitate removal of the bushings. Best bet for most folks would probably be just to add some oil periodically.

--Eric

On Aug 14, 2019 10:29 AM, Stephen Hanselman <kc4sw.io@kc4sw.com> wrote:




Chuck,

You’re right on all your points, except the original oiling was when the
bearing structure was made and the oil was “infused”(??) into the material
(oil-lite bearing)where our added oil is applied to the bearing
surface-spindle interface.

Really it gets down to use what works for you.  I’ve also had good luck
with WD-40 which isn’t ever a lubricant.

Regards,

Stephen Hanselman
Datagate Systems, LLC
3107 North Deer Run Road #24
Carson City, Nevada, 89701
(775) 882-5117 office
(775) 720-6020 mobile
s.hanselman@datagatesystems.com
www.datagatesystems.com
a Service Disabled, Veteran Owned Small Business
DISCLAIMER:
This e-mail and any attachments are intended only for use by the
addressee(s) named herein and may contain legally privileged and/or
proprietary information. If you are not the intended recipient, any
dissemination, distribution or copying of this e-mail and any attachments
is strictly prohibited. If you have received this e-mail in error, please
immediately notify me and permanently delete the original and all copies
and printouts of this e-mail and any attachments.
On Aug 13, 2019, at 14:22, Richard Knoppow <dickburk@ix.netcom.com>
wrote:

   I am not so sure about what additives there are in engine oil. One can
get good quality SAE 20 machine oil at many hardware stores. 3-in-one puts
it up in a blue can (red can is something else). Also as Kano Microil,
very highly refined petroleum based oil, wax free, and does not gum. Most
of these blower bearings are so called "life time lubricated" meaning it
works until it doesn't. They are made from sintered bronze with oil held
in the spongy metal. You can't really re-lubricate them in any easy way
but they will hold oil for a reasonable time.
   Hewlett-Packard used blowers with a rubber seal at one end. They could
be re-lubricated using a syringe to poke through the seal and inject some
oil. I have no idea if the Tek blowers are similar.  Unfortunately, once
the bearings run dry they will become galled and run rough despite having
new lubricant.
   I agree with you that mixing silicon oil or grease with petroleum
lubricant is not a good idea.

On 8/13/2019 2:03 PM, Chuck Harris wrote:
Why?
Silicone oil isn't miscible with the original oil, and
you are not going to make the motor become maintenance
free, no matter what you do with oils.
Just give it some motor oil, thin like SAE5 or 10 is fine.
Detergent isn't like the stuff you wash your clothes in,
it will not cause any problems, in spite of its suggestive
name.
The synthetic doesn't oxidize as quickly as the old oil
did, but then any modern oil is much better in that regard.
The last time anyone lubed your scope fan was likely 40
years ago and yet, it still works.  Give it a couple of
drops of oil, and move on... be happy!
-Chuck Harris
Stephen Hanselman wrote:
I've read some of the answers and wanted to add my two cents.  We use
marvel
mystery oil which seems ok so far.  I was thinking about using silicon
based
gun oil though

steve
--
Richard Knoppow
dickburk@ix.netcom.com
WB6KBL
Re: non-gumming oil

Stephen Hanselman
 

Chuck,

You’re right on all your points, except the original oiling was when the bearing structure was made and the oil was “infused”(??) into the material (oil-lite bearing)where our added oil is applied to the bearing surface-spindle interface.

Really it gets down to use what works for you. I’ve also had good luck with WD-40 which isn’t ever a lubricant.

Regards,

Stephen Hanselman
Datagate Systems, LLC
3107 North Deer Run Road #24
Carson City, Nevada, 89701
(775) 882-5117 office
(775) 720-6020 mobile
s.hanselman@datagatesystems.com
www.datagatesystems.com
a Service Disabled, Veteran Owned Small Business
DISCLAIMER:
This e-mail and any attachments are intended only for use by the addressee(s) named herein and may contain legally privileged and/or proprietary information. If you are not the intended recipient, any dissemination, distribution or copying of this e-mail and any attachments is strictly prohibited. If you have received this e-mail in error, please immediately notify me and permanently delete the original and all copies and printouts of this e-mail and any attachments.

On Aug 13, 2019, at 14:22, Richard Knoppow <dickburk@ix.netcom.com> wrote:

I am not so sure about what additives there are in engine oil. One can get good quality SAE 20 machine oil at many hardware stores. 3-in-one puts it up in a blue can (red can is something else). Also as Kano Microil, very highly refined petroleum based oil, wax free, and does not gum. Most of these blower bearings are so called "life time lubricated" meaning it works until it doesn't. They are made from sintered bronze with oil held in the spongy metal. You can't really re-lubricate them in any easy way but they will hold oil for a reasonable time.
Hewlett-Packard used blowers with a rubber seal at one end. They could be re-lubricated using a syringe to poke through the seal and inject some oil. I have no idea if the Tek blowers are similar. Unfortunately, once the bearings run dry they will become galled and run rough despite having new lubricant.
I agree with you that mixing silicon oil or grease with petroleum lubricant is not a good idea.

On 8/13/2019 2:03 PM, Chuck Harris wrote:
Why?
Silicone oil isn't miscible with the original oil, and
you are not going to make the motor become maintenance
free, no matter what you do with oils.
Just give it some motor oil, thin like SAE5 or 10 is fine.
Detergent isn't like the stuff you wash your clothes in,
it will not cause any problems, in spite of its suggestive
name.
The synthetic doesn't oxidize as quickly as the old oil
did, but then any modern oil is much better in that regard.
The last time anyone lubed your scope fan was likely 40
years ago and yet, it still works. Give it a couple of
drops of oil, and move on... be happy!
-Chuck Harris
Stephen Hanselman wrote:
I've read some of the answers and wanted to add my two cents. We use marvel
mystery oil which seems ok so far. I was thinking about using silicon based
gun oil though

steve
--
Richard Knoppow
dickburk@ix.netcom.com
WB6KBL
17861 - 17880 of 176679  
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