Date   

Re: Machinable Potting Material ???

Mike D
 

He is wanting to replace stripped inserts in knobs, seems like a great
application for easily tap-able jb weld. No concern about viscosity in that
application.

I'm not sure Micromark's bismuth/tin allow would hold a thread for very
long though.

On Sat, Aug 18, 2018 at 8:05 PM james morton <JRM38510@...> wrote:

Warming the JB Weld will decrease the viscosity. I used to pot solid
state modules for the side-winder AIM_9H using Hysol epoxy, it was done in
a vacum chamber, no voids or bubbles allowed.

On Sat, Aug 18, 2018 at 5:21 PM, Richard L. Wurdack <dickw@...>
wrote:

Micromark has some low-temp casting materials <= 160 degrees F. (Metal)

R.


----- Original Message ----- From: "Mike D" <vfd.ninja@...>
To: <TekScopes@groups.io>
Sent: Saturday, August 18, 2018 4:16 PM
Subject: Re: [TekScopes] Machinable Potting Material ???


JB weld works well for this.

Mike kd5rjz

On Sat, Aug 18, 2018 at 4:55 PM, Paul Koretko <@WA0BAG> wrote:

Greetings,
I'm trying to save a couple old plastic knobs that have stripped set
screw
threads, that don't have brass inserts. I remember reading someplace
about
a machinable potting material that is easily flowed into a mold. I've
tried JB Weld, but it doesn't flow well. It has a tendency to leave
void
areas. I want to drill a new set screw hole and hand tap it for 4-40
set
screw.
I remember seeing some discussion on potting material on one of the
groups
I read, so I'm asking for help. Any advice will be appreciated. I
will
also post this to some of the other groups I read.
TNX es 73 de WABAG ..
Paul K.












Re: Tektronix 465,NO Trigger

Fabio Trevisan
 

Hello John,
I'm glad you made progress in so little time.

On the tekwiki website, down there is a reference material section and a Tektronix semiconductor design catalog.
Link is here:
http://w140.com/Tektronix_Xref_sm.pdf
There you will find the specs of those FETs,
They are selected matched pairs of 2N4416.
Those are out of production but they're not hard to find.
Ideally, you would need to buy a bunch of them and try to find between them, a pair that are similar to each other and are as close as possible to the target specification.
IIRC, those are selected to have Idss between 10 and 15mA, while the plain 2N4416s are anything between 5 and 15mA.
The voltage offset you're getting is due to the only two last FETs you got working are not matched.
The A level triggering center trimpot is able to compensate for up to 200mV so, you' re at the edge of the cliff but still workable.
Still, with the offset so high, they are so unmatched that they will not track well one to another with changes in temperature.
You may be lucky to find the matched ones at Sphere Research, or Qservice (the latter probably better choice for you as they're in Greece)..
Those are two very well known traders of Tek parts, that many in this group can endorse (me included, for Sphere, I never dealt with Qservice).

Good luck,

Rgrds,

Fabio

On Sat, Aug 18, 2018 at 06:04 PM, Bert Haskins wrote:




On 8/18/2018 3:49 PM, John Stoole wrote:
Hi Bert
No its not the Tunnel Diodes that are faulty its the Trigger driver JFET's
have blown, in fact one of them was cracked which I was unable to see until I
removed the Heatsink, so I hope someone can suggest a substitute
Regards
John


Re: Machinable Potting Material ???

james morton
 

An alternate approach would be to hand machine delrin rod on a drill press.

On Sat, Aug 18, 2018 at 6:05 PM, james morton <jrm38510@...> wrote:

Warming the JB Weld will decrease the viscosity. I used to pot solid
state modules for the side-winder AIM_9H using Hysol epoxy, it was done in
a vacum chamber, no voids or bubbles allowed.

On Sat, Aug 18, 2018 at 5:21 PM, Richard L. Wurdack <dickw@...>
wrote:

Micromark has some low-temp casting materials <= 160 degrees F. (Metal)

R.


----- Original Message ----- From: "Mike D" <vfd.ninja@...>
To: <TekScopes@groups.io>
Sent: Saturday, August 18, 2018 4:16 PM
Subject: Re: [TekScopes] Machinable Potting Material ???


JB weld works well for this.

Mike kd5rjz

On Sat, Aug 18, 2018 at 4:55 PM, Paul Koretko <@WA0BAG> wrote:

Greetings,
I'm trying to save a couple old plastic knobs that have stripped set
screw
threads, that don't have brass inserts. I remember reading someplace
about
a machinable potting material that is easily flowed into a mold. I've
tried JB Weld, but it doesn't flow well. It has a tendency to leave
void
areas. I want to drill a new set screw hole and hand tap it for 4-40
set
screw.
I remember seeing some discussion on potting material on one of the
groups
I read, so I'm asking for help. Any advice will be appreciated. I will
also post this to some of the other groups I read.
TNX es 73 de WABAG ..
Paul K.










Re: Machinable Potting Material ???

james morton
 

Warming the JB Weld will decrease the viscosity. I used to pot solid
state modules for the side-winder AIM_9H using Hysol epoxy, it was done in
a vacum chamber, no voids or bubbles allowed.

On Sat, Aug 18, 2018 at 5:21 PM, Richard L. Wurdack <dickw@...>
wrote:

Micromark has some low-temp casting materials <= 160 degrees F. (Metal)

R.


----- Original Message ----- From: "Mike D" <vfd.ninja@...>
To: <TekScopes@groups.io>
Sent: Saturday, August 18, 2018 4:16 PM
Subject: Re: [TekScopes] Machinable Potting Material ???


JB weld works well for this.

Mike kd5rjz

On Sat, Aug 18, 2018 at 4:55 PM, Paul Koretko <@WA0BAG> wrote:

Greetings,
I'm trying to save a couple old plastic knobs that have stripped set
screw
threads, that don't have brass inserts. I remember reading someplace
about
a machinable potting material that is easily flowed into a mold. I've
tried JB Weld, but it doesn't flow well. It has a tendency to leave void
areas. I want to drill a new set screw hole and hand tap it for 4-40 set
screw.
I remember seeing some discussion on potting material on one of the
groups
I read, so I'm asking for help. Any advice will be appreciated. I will
also post this to some of the other groups I read.
TNX es 73 de WABAG ..
Paul K.










Re: TEK 466 Analog Storage

toby@...
 

On 2018-08-18 4:16 PM, Paul B. via Groups.Io wrote:
Thanks, but that link you provided only seems to point to an extremely high resolution scan of the front cover of the manual (69Mb's worth!) unless there's something I'm doing wrong!

It's a multipage TIFF -- most system previewers (Windows, OS X) can page
through it.

Sorry, I should have warned about that :-)

--Toby



But no worries, I found another manual/service book quite easily
elsewhere and will study that.
In the mean time, if anyone knows what the screen should appear like at switch-on (which doesn't seem to be covered in the manual i downloaded) please feel free to chip in here with a description; thanks!




Re: Machinable Potting Material ???

Richard L. Wurdack <dickw@...>
 

Micromark has some low-temp casting materials <= 160 degrees F. (Metal)

R.

----- Original Message -----
From: "Mike D" <vfd.ninja@...>
To: <TekScopes@groups.io>
Sent: Saturday, August 18, 2018 4:16 PM
Subject: Re: [TekScopes] Machinable Potting Material ???


JB weld works well for this.

Mike kd5rjz

On Sat, Aug 18, 2018 at 4:55 PM, Paul Koretko <@WA0BAG> wrote:

Greetings,
I'm trying to save a couple old plastic knobs that have stripped set screw
threads, that don't have brass inserts. I remember reading someplace about
a machinable potting material that is easily flowed into a mold. I've
tried JB Weld, but it doesn't flow well. It has a tendency to leave void
areas. I want to drill a new set screw hole and hand tap it for 4-40 set
screw.
I remember seeing some discussion on potting material on one of the groups
I read, so I'm asking for help. Any advice will be appreciated. I will
also post this to some of the other groups I read.
TNX es 73 de WABAG ..
Paul K.





Re: Machinable Potting Material ???

Bill Riches
 

Is the knob large enough to use a 6-32 set screw? If so make sure you use a correct numbered drill with the tap.

73,

Blll, WA2DVU
Cape Mah

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Paul Koretko
Sent: Saturday, August 18, 2018 5:55 PM
To: TekScopes@groups.io
Subject: [TekScopes] Machinable Potting Material ???

Greetings,
I'm trying to save a couple old plastic knobs that have stripped set screw threads, that don't have brass inserts. I remember reading someplace about a machinable potting material that is easily flowed into a mold. I've tried JB Weld, but it doesn't flow well. It has a tendency to leave void areas. I want to drill a new set screw hole and hand tap it for 4-40 set screw.
I remember seeing some discussion on potting material on one of the groups I read, so I'm asking for help. Any advice will be appreciated. I will also post this to some of the other groups I read.
TNX es 73 de WABAG ..
Paul K.


Re: Machinable Potting Material ???

Mike D
 

JB weld works well for this.

Mike kd5rjz

On Sat, Aug 18, 2018 at 4:55 PM, Paul Koretko <@WA0BAG> wrote:

Greetings,
I'm trying to save a couple old plastic knobs that have stripped set screw
threads, that don't have brass inserts. I remember reading someplace about
a machinable potting material that is easily flowed into a mold. I've
tried JB Weld, but it doesn't flow well. It has a tendency to leave void
areas. I want to drill a new set screw hole and hand tap it for 4-40 set
screw.
I remember seeing some discussion on potting material on one of the groups
I read, so I'm asking for help. Any advice will be appreciated. I will
also post this to some of the other groups I read.
TNX es 73 de WABAG ..
Paul K.




Re: TEK 466 Analog Storage

Paul B.
 

Just what I was looking for; many thanks.


Re: Tek 2467b test 05 error

Siggi
 

On Fri, 17 Aug 2018 at 23:01 <Sscandizzo@...> wrote:

I'm definitely new to scope repair.

But old hand at other electronics repair?


The 2467 could not be passed up but it did come with the faults when I
purchased it. I do have an inexpensive digital scope that I hope I can use
to bring this one back to life.

Excellent - for the most part you don't need a whole lot'o'scope to
diagnose another scope. The power supply ripple is typically measured under
the 20MHz bandwidth limiter, and the digital & control signalling on this
scope is mostly below 1MHz.

The only other instrument you need is a decent DMM (or the like).


I'll need a quiet afternoon to open it up. I will check the points you
have mentioned and post my results.
Looking forward to it - good hunting!


Machinable Potting Material ???

Paul Koretko
 

Greetings,
I'm trying to save a couple old plastic knobs that have stripped set screw threads, that don't have brass inserts. I remember reading someplace about a machinable potting material that is easily flowed into a mold. I've tried JB Weld, but it doesn't flow well. It has a tendency to leave void areas. I want to drill a new set screw hole and hand tap it for 4-40 set screw.
I remember seeing some discussion on potting material on one of the groups I read, so I'm asking for help. Any advice will be appreciated. I will also post this to some of the other groups I read.
TNX es 73 de WABAG ..
Paul K.


Re: Tektronix 465,NO Trigger

Bert Haskins
 

On 8/18/2018 3:49 PM, John Stoole wrote:
Hi Bert
No its not the Tunnel Diodes that are faulty its the Trigger driver JFET's have blown, in fact one of them was cracked which I was unable to see until I removed the Heatsink, so I hope someone can suggest a substitute
Regards
John
mi0dfg
If you feel like doing a lot of work, you can look up the part number and cross-reference it to find what else it is used in.
Some Tek parts are common and some are made out of unatatium, hope I spelled that right.

Are these dual FETs?

Bert

On 18 August 2018 at 19:07 Bert Haskins <bhaskins@...> wrote:




On 8/18/2018 1:33 PM, John Stoole wrote:
Well Success at last Fabio !!!!!

I did not realize that the FET's were in sockets under the heatsinks, I decided to change them and I still had no Trigger, as they were out I tested the FETt's on my component tester and there was one faulty on the B TRIG and one on the A TRIG so I used the good ones on Trig A and found that as I turned the Trigger Level control to about 3 o'clock it locked and I had Trigger sync, and the trigger lamp is on. The voltages on the U640 chip 14/15 is 0v but 2/3 is 179 mv I have had a look around and have not found the reason for this ?
Have you any thoughts for a suitable replacement for the FET's?, something I might get locally in UK
We are getting there thanks to you
John

I'm really surprised that no one else has mentioned the infamous tunnel
diode problem.
This often shows up on a lot of the older Tek products and the are many,
many previous discussions on this and other lists.
The problem summery is that as the TDs age their characteristics
change/drift,etc

Some people have managed to obtain replacements that are as good or even
better than the Tek original parts.
This includes me.
I had this on a 465B and some other Tek stuff.
My first solution was to swap the pairs from the B timebase with those
from the A section.
This worked for a few years but course, the B timebase was now bad.
Later I had problems in some 7K units and my good old lugable Cosser scope.
To shorten a very long story, I ended up spending a lot of money on 4,7
and 10 ma. diodes from a ?Russian? ebay seller/s.
I "selected" the trigger diodes using a combination of several test
methods and used the ones that if liked in my 465B.
My 465B now triggers solidly well above 300Mhz.

Now the dirty part is that I have had several old TDs that looked good
on the curve tracer but did not work well in any instrument.
I really don't know the real why of this but my stuff works!.

GOOD LUCK,
Bert




Re: TEK 466 Analog Storage

Colin Herbert
 

A good start would be to have the controls thus:
POWER Off
INTEN Fully ccw
FOCUS Midrange
SCALE ILLUM As desired
VERT MODE Ch 1
POSITION Midrange
VOLTS/DIV 5V
VAR VOLTS/DIV Calibrated detent
AC-GND-DC DC
INVERT Normal
TRIG VIEW/BANDWIDTH Full bandwidth (No yellow showing)
STORAGE Non Store
TRIGGER (A & B):
COUPLING AC
LEVEL Midrange
SLOPE +
A TRIGGER SOURCE Norm
B (DELAYED) TRIGGER SOURCE Starts after delay
TRIG MODE Auto
A TRIG HOLDOFF Norm
SWEEP (A & B):
HORIZ DISPLAY A
A TIME/DIV 1ms
B TIME/DIV 1ms
VAR TIME/DIV Calibrated detent
DELAY TIME POSITION Full counterclockwise
X10 MAG Off (button out)
Position (Horiz) Midrange
Fine Midrange

Check that the line voltage selector and the Regulating Range Selectors are correctly set for your area.
Pull the power switch on. After about a minute, turn the INTEN control clockwise until you see a horizontal scan. If you can't see this, press the "BEAM FINDER" button and adjust the position controls to roughly centre the display, if you see one. If there's no display at all, you might have any number of faults.
If you connect a probe plugged into the Ch 1 input BNC to a signal source (the CALIBRATOR loop on the rear of the scope will do just fine), you should see a display of the waveform. You might need to increase the VOLTS/DIV setting to see the waveform initially, depending on the amplitude of the applied signal.

A lot of this is taken from the 466 Service Manual, see p 2-11, so RTFM.

E&OE.

Good Luck, Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Paul B. via Groups.Io
Sent: 18 August 2018 21:16
To: TekScopes@groups.io
Subject: Re: [TekScopes] TEK 466 Analog Storage

Thanks, but that link you provided only seems to point to an extremely high resolution scan of the front cover of the manual (69Mb's worth!) unless there's something I'm doing wrong! But no worries, I found another manual/service book quite easily elsewhere and will study that.
In the mean time, if anyone knows what the screen should appear like at switch-on (which doesn't seem to be covered in the manual i downloaded) please feel free to chip in here with a description; thanks!


Re: TEK 466 Analog Storage

Harvey White
 

On Sat, 18 Aug 2018 13:16:06 -0700, you wrote:

Thanks, but that link you provided only seems to point to an extremely high resolution scan of the front cover of the manual (69Mb's worth!) unless there's something I'm doing wrong! But no worries, I found another manual/service book quite easily elsewhere and will study that.
In the mean time, if anyone knows what the screen should appear like at switch-on (which doesn't seem to be covered in the manual i downloaded) please feel free to chip in here with a description; thanks!
I have a feeling that it depends on whether or not it is in storage
mode at startup.

With storage mode turned off, IIRC, any storage scope ought to look
"normal".

In storage mode, then you'll get a screen depending on the type of
storage (there are several) and the appropriate controls.

Harvey





Re: TEK 466 Analog Storage

Paul B.
 

Thanks, but that link you provided only seems to point to an extremely high resolution scan of the front cover of the manual (69Mb's worth!) unless there's something I'm doing wrong! But no worries, I found another manual/service book quite easily elsewhere and will study that.
In the mean time, if anyone knows what the screen should appear like at switch-on (which doesn't seem to be covered in the manual i downloaded) please feel free to chip in here with a description; thanks!


Re: Tektronix 465,NO Trigger

John Stoole
 

Hi Bert
No its not the Tunnel Diodes that are faulty its the Trigger driver JFET's have blown, in fact one of them was cracked which I was unable to see until I removed the Heatsink, so I hope someone can suggest a substitute
Regards
John
mi0dfg

On 18 August 2018 at 19:07 Bert Haskins <bhaskins@...> wrote:




On 8/18/2018 1:33 PM, John Stoole wrote:
Well Success at last Fabio !!!!!

I did not realize that the FET's were in sockets under the heatsinks, I decided to change them and I still had no Trigger, as they were out I tested the FETt's on my component tester and there was one faulty on the B TRIG and one on the A TRIG so I used the good ones on Trig A and found that as I turned the Trigger Level control to about 3 o'clock it locked and I had Trigger sync, and the trigger lamp is on. The voltages on the U640 chip 14/15 is 0v but 2/3 is 179 mv I have had a look around and have not found the reason for this ?
Have you any thoughts for a suitable replacement for the FET's?, something I might get locally in UK
We are getting there thanks to you
John

I'm really surprised that no one else has mentioned the infamous tunnel
diode problem.
This often shows up on a lot of the older Tek products and the are many,
many previous discussions on this and other lists.
The problem summery is that as the TDs age their characteristics
change/drift,etc

Some people have managed to obtain replacements that are as good or even
better than the Tek original parts.
This includes me.
I had this on a 465B and some other Tek stuff.
My first solution was to swap the pairs from the B timebase with those
from the A section.
This worked for a few years but course, the B timebase was now bad.
Later I had problems in some 7K units and my good old lugable Cosser scope.
To shorten a very long story, I ended up spending a lot of money on 4,7
and 10 ma. diodes from a ?Russian? ebay seller/s.
I "selected" the trigger diodes using a combination of several test
methods and used the ones that if liked in my 465B.
My 465B now triggers solidly well above 300Mhz.

Now the dirty part is that I have had several old TDs that looked good
on the curve tracer but did not work well in any instrument.
I really don't know the real why of this but my stuff works!.

GOOD LUCK,
Bert




Re: Tektronix 465,NO Trigger

Bert Haskins
 

On 8/18/2018 1:33 PM, John Stoole wrote:
Well Success at last Fabio !!!!!

I did not realize that the FET's were in sockets under the heatsinks, I decided to change them and I still had no Trigger, as they were out I tested the FETt's on my component tester and there was one faulty on the B TRIG and one on the A TRIG so I used the good ones on Trig A and found that as I turned the Trigger Level control to about 3 o'clock it locked and I had Trigger sync, and the trigger lamp is on. The voltages on the U640 chip 14/15 is 0v but 2/3 is 179 mv I have had a look around and have not found the reason for this ?
Have you any thoughts for a suitable replacement for the FET's?, something I might get locally in UK
We are getting there thanks to you
John

I'm really surprised that no one else has mentioned the infamous tunnel diode problem.
This often shows up on a lot of the older Tek products and the are many, many previous discussions on this and other lists.
The problem summery is that as the TDs age their characteristics change/drift,etc

Some people have managed to obtain replacements that are as good or even better than the Tek original parts.
This includes me.
I had this on a 465B and some other Tek stuff.
My first solution was to swap the pairs from the B timebase with those from the A section.
This worked for a few years but course, the B timebase was now bad.
Later I had problems in some 7K units and my good old lugable Cosser scope.
To shorten a very long story, I ended up spending a lot of money on 4,7 and 10 ma. diodes from a ?Russian? ebay seller/s.
I "selected" the trigger diodes using a combination of several test methods and used the ones that if liked in my 465B.
My 465B now triggers solidly well above 300Mhz.

Now the dirty part is that I have had several old TDs that looked good on the curve tracer but did not work well in any instrument.
I really don't know the real why of this  but my stuff works!.

GOOD LUCK,
  Bert


Re: tektronix 214 option 94

Colin Herbert
 

This scope is currently on eBay. If it is of any significance, the probes are permanently wired in, according to the description.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Miguel Work
Sent: 16 August 2018 10:25
To: TekScopes@groups.io
Subject: [TekScopes] tektronix 214 option 94


Which is optino 94 for a Tektronix 214?

https://groups.io/g/TekScopes/photo/66992/0?p=Name,,,20,1,0,0


Re: tektronix 214 option 94/ Li-Ion fork

Miguel Work
 

Hi!

My tektronix 214,221 and 222 is now working with lithium batteries.

https://groups.io/g/TekScopes/photo/66992/1?p=Name,,,20,1,0,0

https://groups.io/g/TekScopes/photo/66992/2?p=Name,,,20,1,0,0

Regards

Miguel



-----Mensaje original-----
De: TekScopes@groups.io [mailto:TekScopes@groups.io] En nombre de Kevin Oconnor
Enviado el: sábado, 18 de agosto de 2018 4:02
Para: TekScopes@groups.io
Asunto: Re: [TekScopes] tektronix 214 option 94/ Li-Ion fork

I wouldn't pick to much on Li-Ion chemistry. There are a lot of deployed chemistries and construction methods. Some have problems some don't, just like NiCd & NiMH. I've seen plenty of NiCD rotting in their electronics. Neither Ni has much shelf life, yet I have seen some Li devices wake up after a year on the shelf.
Realistically, all these chemistries have quirky charging and discharging requirements. But if I am designing new hardware for the masses, it is highly unlikely I would be successful selecting NiCd chemistry. Yes, Li-Ion needs a different charging means, but there chips and PCBs for that. Yes, they can balloon and catch fire sometimes. That is a manufacturing QC issue.

Given the choice between a coin NiCd and a postage stamp Li-Ion for a little rechargeable gizmo device, I'd pick the Li battery every time. The coin Ni-Cd is soooo Palm-Pilot era!!!!!

Kjo


Re: Tek 2467b test 05 error

Sscandizzo@...
 

Excellent point, Artekmedia. I'll know soon enough!

-Stefan