Date   
Re: TM500 / 5000 Extenders

Alexandre Souza
 

You can use JAMMA extenders, or sockets/fingerboard pcbs. It is the right
size/pitch. I used it to make my extenders

---8<---Corte aqui---8<---
http://www.tabajara-labs.blogspot.com
http://www.tabalabs.com.br
---8<---Corte aqui---8<---


Em dom., 22 de dez. de 2019 às 12:39, John Griessen <@jgriessen>
escreveu:

On 12/21/19 8:48 AM, Gary Neilson wrote:
I am looking for one possibly two of these extenders of yours.
Please advise if you are still making these.?
Not me.

Dan Meeks built/sold some a little while back though.



Re: TM500 / 5000 Extenders

John Griessen
 

On 12/21/19 8:48 AM, Gary Neilson wrote:
I am looking for one possibly two of these extenders of yours.
Please advise if you are still making these.?
Not me.

Dan Meeks built/sold some a little while back though.

Re: Tek 2465 Problem

Panos
 

More progress to share with you and I hope that I am in the final stage.
Maybe my ignorance, maybe I didn't pay the necessary attention, I had problem on my + - 5 volt power line! The power supply readings initially using another oscilloscope sawed me the problem, but...

Finally I found the 4 schottky rectifier diodes partially damaged. I said partially, because they have very low in ohm resistance (about 130 ohm) when I measure these with forward polarity. Conversely they have a complete cut.
So I think that they don't rectify the voltage at all, or rectify little. Diodes is at A3 Inverter board and marked as CR1113 -14 -15 -16.

I think that +5 volt line is the most important, since every board use this in wide range except the High Voltage one!!
I am very curious to see how much things will improve immediately after their replacement.

For now I need to wait till Monday, because I haven't this exact type available in my box. I have the 1N5408 available but these are general purpose diodes, and not specific like original 1N5821 on my oscilloscope.

Re: Tek 576 Curve Tracer HV Transformer winding

magnustoelle
 

Good Day,
wow, what a nice surprise of a critical replacement part for the 576 lovers. 
Very nice work from what I have seen, Michael!
Have a wonderful holiday time.
Greetings from Bavaria, Germany,
Magnus 
Ed,


Yes, you are exactly right the plastic screw is a critical item with this type of core and mounting method.  My instructions will include those important details with the finished product.  This little tidbit of information came to me while researching specifics for this product construction.  The reason that we did not use clips was that this would have made the core effectively wider and may not have fit.  This was also cheaper to produce.  I decided to use the existing center hole and plastic screw as an alternative to the clips.  Obviously, I had to drill a hole, centered between the two existing holes to mount the new transformer from.  I can also provide a 3D printed "adapter" for those who do not wish to drill another hole in their instrument.  More to come very soon.     

--
Michael Lynch
Dardanelle, AR

Re: Tek 576 Curve Tracer HV Transformer winding

Mlynch001
 

Ed,

Yes, you are exactly right the plastic screw is a critical item with this type of core and mounting method. My instructions will include those important details with the finished product. This little tidbit of information came to me while researching specifics for this product construction. The reason that we did not use clips was that this would have made the core effectively wider and may not have fit. This was also cheaper to produce. I decided to use the existing center hole and plastic screw as an alternative to the clips. Obviously, I had to drill a hole, centered between the two existing holes to mount the new transformer from. I can also provide a 3D printed "adapter" for those who do not wish to drill another hole in their instrument. More to come very soon.

--
Michael Lynch
Dardanelle, AR

Re: Tek 2235 Repair

guy232
 

Also for posting photos you may find imgur.com useful as a free image host. You upload there and it gives you a url to post the album. It doesn't require you to register but if you create a free account you'll always have your album history available which is useful.

Re: Tek 2235 Repair

guy232
 

Grats on the 22xx series scope! I'm not an expert but am a familiar novice who spent a lot of time researching the 22xx series, feel free to read the rest of this post for some pointers on useful things i've found that may or may not be of interest to you:

The 2213A, 2215A, and 2235 are all quite similar in parts/layout. Odds are that you may be able to get ideas on troubleshooting your 2235 from those models as well by using google/this group to search for your problem and adding "2213A, 2215A, 2235, 2235A" onto your search string. The 2235A is also quite similar BUT it has a few different value parts in the HV area and elsewhere I imagine.

The 2235 eevblog post linked by John is quite good and is actually still actively being posted on as of today.

I also have a 2213A post on eevblog and on here, it mostly just covers replacing aging parts/fault finding which ended up being a cracked joint in the HV area.

I know you aren't seeking a parts list but if in the future you're insterested in one then visit the link below and scroll all the way to the bottom of the thread where member "Redwire" attached his revised spreadsheet file. It lists all of the caps/tantalums/films/"focus" resistors etc in the HV. It has parts for both the 2235 and 2235A, it is quite excellent, I used the 2235 portion to do my entire 2213A's HV area. You'll need to make a account to access it:
https://www.badcaps.net/forum/showthread.php?t=71125

There are also a few videos on youtube of people troubleshooting their 2235 and 2235A if those interest you. A couple of them were of interest to a novice like me, I cannot vouch for their quality though as i'm not an EE or experienced technician.

Cheers and will be watching this thread for sure!

Re: Tek 2235 Repair

John Williams
 

Best info I could find quickly:

https://www.eevblog.com/forum/testgear/tektronix-2235-repair-thread/

Good hunting.

John

Re: Tek 1480C waveform monitor FREE

nielsentelecom@sbcglobal.net
 

I'm waking up this thread to see if anyone is interested. See the topic thread for the dimensions and weight. I really need to get rid of it.

NielsenTelecom

Re: Tek 576 Curve Tracer HV Transformer winding

Ed Breya
 

Looks like a nice alternative - good job.

Michael did it right, with a plastic screw, but didn't explicitly mention its importance. Too much compression on the center of a gapped pot core will break it. Using a metal screw makes it easier to break the core, and will cause losses due to induction in the high field zone of the gap (where most of the energy is stored), and may upset operation. So, a nonmetallic fastener, not too tight, is the best for through-hole mounting. Otherwise, an external core clip or method may be used, that doesn't involve the center hole. There are snap-on metal mounting clips available for pot cores, that grab the outer part, and provide mounting ears.

Ed

Re: Tek 576 Curve Tracer HV Transformer winding

Mlynch001
 

Regarding rewinding the 576 HV Transformer. After wasting a lot of time and money attempting to get this to work properly, I found a way to get a professional job done that works and am offering these for sale to members of the group first. See Below:

https://groups.io/g/TekScopes/message/162312

I have received my prototype 576 HV Transformer. It is installed and working as I type. I am in the process of "burning in" the prototype. I will operate the instrument for a minimum of 48 hours before I order any of these parts and before offering for sale.

This is a MADE in the USA Part, so the quality is very high. The factory that is making these is not selling these to anyone else, they are a custom build for me, not off the shelf items.

This is a Functional Equivalent of TEKTRONIX p/n 120-0612-03. Built using the specifications provided on that TEKTRONIX Drawing.

Dimensions are 43mm dia and 31mm deep. The core is a round profile with a single mounting hole through the center of the core.

You can find the photos here: https://groups.io/g/TekScopes/album?id=235927

I verified voltages on my test unit and they are well within the original TEKTRONIX specifications.

-4kV = -3869 VDC
225V = 229.6 VDC

I will be ordering some of these and placing them for sale, initially to group members at preferred pricing and on a first come - first served basis. I will also offer them on E-Bay as well, if there are any left from the initial order; however the price on E-bay will be somewhat higher (This is to cover the exorbitant fees that E-Bay charges sellers). Members of this forum may contact me OFF-LIST for additional information. Cost to members of this forum will be $107.50 each, this includes free USPS PRIORITY MAIL Shipping to the USA only. INTERNATIONAL Customers will be charged $107.50 USD, plus applicable USPS postage to your location. I have shipped very little to international customers, so I have no idea what the cost will be. The USPS Website is very vague and variable as to the cost of international shipping. Payment will be accepted through PayPal.

@mlynch001<

These DO NOT look like the originals, however, they will mount in the original position and still allow the cover to fit onto the HV section. (See Pictures File)

There are two different mounting methods. I drilled a single hole, centered between the original holes on the HV back plate and mounted the XFMR directly in the original location. I am also willing to 3D print a small adapter to allow those who do not wish to drill their unit to mount this, using the original holes. Installation will require some additional minor hardware to complete the installation. I will supply a transformer, instructions and with or without the printed mount (per your instructions).

Wiring is exactly as original, per the LATE model TYPE 576 Service Manual Schematic. Be aware that the OLDER version of some manuals show a different number sequence on the primary side leads. If you wire this transformer up as the old schematic shows, it could be damaged and certainly will not work.

I will include instructions, schematics, BOM and other information with each unit that is purchased.

I expect to order the initial order about Jan 5th and it is expected to take about 6 weeks to receive the parts. This is due to the fact that the cores on the XFMR have a custom "Non-standard" gap, machined to match the Original design specification. Based on this timetable, I would expect the first units to arrive here about the last week of February 2020. I will ship any paid orders immediately, at that time.

Again, Contact me OFF LIST for any further questions or details.

Sincerely,

--
Michael Lynch
Dardanelle, AR

Tek 2235 Repair

Oscar Anderson
 

Hello, I recently purchased a Tektronix 2235 at a university auction for about $50. Given that they were selling off six or seven of them, I was surprised to find that mine has some issues.

When powered up, it seems to have no trace, however when I push the "beam find" button, I see some part of a trace that can be moved around with the vertical position controls and seems to be controlled appropriately by the time base. Not quite sure how to attach photos to show this (as you can probably guess, I am new here).

I'd appreciate any guidance on where to start.

I measured the supply rails, and they all look fine. I have some experience troubleshooting analog electronics, but not oscilloscopes in particular. I do have other oscilloscopes to use for the troubleshooting procedure, so that is not an issue. Looks like the service manual is pretty good for this scope.

Re: TM500 / 5000 Extenders

Gary Neilson
 

I am looking for one possibly two of these extenders of yours.
Please advise if you are still making these.?

Thanks
Gary Neilson

Type 576 HV transfomer replacement part, Progress

Mlynch001
 

All:

I have received my prototype 576 HV Transformer. It is installed and working as I type. I am in the process of "burning in" the prototype. I will operate the instrument for a minimum of 48 hours before I order any of these parts and before offering for sale.

This is a MADE in the USA Part, so the quality is very high. The factory that is making these is not selling these to anyone else, they are a custom build for me, not off the shelf items.

This is a Functional Equivalent of TEKTRONIX p/n 120-0612-03. Built using the specifications provided on that TEKTRONIX Drawing.

Dimensions are 43mm dia and 31mm deep. The core is a round profile with a single mounting hole through the center of the core.

You can find the photos here: https://groups.io/g/TekScopes/album?id=235927

I verified voltages on my test unit and they are well within the original TEKTRONIX specifications.

-4kV = -3869 VDC
225V = 229.6 VDC

I will be ordering some of these and placing them for sale, initially to group members at preferred pricing and on a first come - first served basis. I will also offer them on E-Bay as well, if there are any left from the initial order; however the price on E-bay will be somewhat higher (This is to cover the exorbitant fees that E-Bay charges sellers). Members of this forum may contact me OFF-LIST for additional information. Cost to members of this forum will be $107.50 each, this includes free USPS PRIORITY MAIL Shipping to the USA only. INTERNATIONAL Customers will be charged $107.50 USD, plus applicable USPS postage to your location. I have shipped very little to international customers, so I have no idea what the cost will be. The USPS Website is very vague and variable as to the cost of international shipping. Payment will be accepted through PayPal.

@mlynch001<
These DO NOT look like the originals, however, they will mount in the original position and still allow the cover to fit onto the HV section. (See Pictures File)

There are two different mounting methods. I drilled a single hole, centered between the original holes on the HV back plate and mounted the XFMR directly in the original location. I am also willing to 3D print a small adapter to allow those who do not wish to drill their unit to mount this, using the original holes. Installation will require some additional minor hardware to complete the installation. I will supply a transformer, instructions and with or without the printed mount (per your instructions).

Wiring is exactly as original, per the LATE model TYPE 576 Service Manual Schematic. Be aware that the OLDER version of some manuals show a different number sequence on the primary side leads. If you wire this transformer up as the old schematic shows, it could be damaged and certainly will not work.

I will include instructions, schematics, BOM and other information with each unit that is purchased.

I expect to order the initial order about Jan 5th and it is expected to take about 6 weeks to receive the parts. This is due to the fact that the cores on the XFMR have a custom "Non-standard" gap, machined to match the Original design specification. Based on this timetable, I would expect the first units to arrive here about the last week of February 2020. I will ship any paid orders immediately, at that time.

Again, Contact me OFF LIST for any further questions or details.

Sincerely,

Michael

--
Michael Lynch
Dardanelle, AR

Re: Tektronix 531A

John Williams
 

My email address should show up under my name? Anyway it is books4you at telusdot net.

Re: Tektronix 531A

John Griessen
 

On 12/20/19 1:17 PM, Brenda via Groups.Io wrote:
How can I contact you offline?
If using an email reader, just change xxx=yyy.com@groups.io to xxx@...

Re: Tektronix 531A

Brenda
 

Hello John. Actually the plastic mount at the rear of the CRT is perfectly intact, although bent back possibly due to the implosion of the CRT. I think it was dropped in the front as I didn't mention that the red knobs on the CA plug in was broke in half and the lower ground terminal was snapped off under the sawtooth out jack. How can I contact you offline?

Thanks so much!!
Brenda

Quantity Correction Re: [HP-Agilent-Keysight-equipment] FS: sets of NOS concentric control knobs

Brad Thompson
 

Brad Thompson via Groups.Io wrote on 12/18/2019 7:48 PM:
Hello-- please note...

***Henceforth, if you have any questions regarding this or any other FS offers that
I may make, please reply directly to my e-mail address. Thank you for your consideration.***

Brad Thompson via Groups.Io wrote on 12/6/2019 10:29 A
Hello--
I'm offering FS sets of NOS concentric control knobs. These have longitudinally-grooved
surfaces and black cursor markings which contrast nicely with the aluminum knob material.

The top knob has a black insert.  Each knob gets secured to its control shaft by two
.050-inch hex setscrews. A .jpg-format photo is available on request.

Bottom knob: 0.625 inches in diameter, 0.56 inches high, 0.25 inch through hole
Top knob: 0.425 inches in diameter, 0.56 inches high, 0.125 inch blind hole.

(Please note that the knobs are made from aluminum, a conductive metal,
and hence will pose a shock hazard if you're accustomed to the bad practice
of floating the ungrounded chassis of an instrument.)

Each set comprises FOUR top/bottom pairs and as a bonus while
the supply lasts, four skirted plastic knobs with 0.125-inch
brass-insert blind hole and one 0.050-inch setscrew.

I'm asking $10.00 per package  (four two-piece knobsets plus bonus knobs), which includes
USPS first-class mail to U.S. locations.

Questions welcomed, PayPal honored.
Thanks, and 73--

Brad  AA1IP

Re: Caps

Jamie Ostrowski
 

I should probably keep my mouth shut but I'm not that really that smart.

I think that most people are smart enough to tell if someone using all caps
is yelling at them by using tools such as "context", but if there is any
doubt, it's actually okay to respond and ask if they're upset.

On Fri, Dec 20, 2019 at 8:32 AM Chuck Harris <cfharris@...> wrote:

Rich,

Since you addressed this to me on the group, I am going
to reply, regardless of Dennis's objections.

If you are offended so easily that caps letters triggers
you, please keep it to yourself. None of us needs to know
about your emotional immaturity.

What you are doing is being a social justice warrior (SJW),
and being offended for those who aren't "woke" enough to
be offended by themselves.

I don't need your help with that. I am pretty sure nobody
else does either.

-Chuck Harris

Richard R. Pope wrote:
Chuck,
If we don't speak up than people don't learn and grow. It isn't
about being
offended it is about being compassionate and respectful of other peoples
feelings. If
someone uses all caps or a lot of fully Capitalized words I don't even
bother to read
the message. It is immediately deleted. Just like I won't tolerate some
yelling or
screaming at me. If someone wants to behave like a jerk than I choose
not to have
anything to do with them.
GOD Bless and Thanks,
rich! BTW: Merry Christmas to all!

On 12/19/2019 10:35 PM, Chuck Harris wrote:
Many were using Model 33ASR teletypes, and indeed had no capslock,
only caps.

Others were so used to teletypes, that they preferred to stay with
all caps.

Honestly, life is much easier if you stop worrying about stuff like
this. You will never please everyone, why try? Do it the way you
want.

Learn to be tolerant. Someday, someone may even be tolerant of your
idiotsyncrazies.

-Chuck Harris


Re: Caps

Chuck Harris
 

Rich,

Since you addressed this to me on the group, I am going
to reply, regardless of Dennis's objections.

If you are offended so easily that caps letters triggers
you, please keep it to yourself. None of us needs to know
about your emotional immaturity.

What you are doing is being a social justice warrior (SJW),
and being offended for those who aren't "woke" enough to
be offended by themselves.

I don't need your help with that. I am pretty sure nobody
else does either.

-Chuck Harris

Richard R. Pope wrote:

Chuck,
If we don't speak up than people don't learn and grow. It isn't about being
offended it is about being compassionate and respectful of other peoples feelings. If
someone uses all caps or a lot of fully Capitalized words I don't even bother to read
the message. It is immediately deleted. Just like I won't tolerate some yelling or
screaming at me. If someone wants to behave like a jerk than I choose not to have
anything to do with them.
GOD Bless and Thanks,
rich! BTW: Merry Christmas to all!

On 12/19/2019 10:35 PM, Chuck Harris wrote:
Many were using Model 33ASR teletypes, and indeed had no capslock,
only caps.

Others were so used to teletypes, that they preferred to stay with
all caps.

Honestly, life is much easier if you stop worrying about stuff like
this. You will never please everyone, why try? Do it the way you
want.

Learn to be tolerant. Someday, someone may even be tolerant of your
idiotsyncrazies.

-Chuck Harris