Date   
Re: Extenders

 

John,

I am interested to buy two extender kits, if you still have them. If so, how could I order?

Merry Xmas,
Peter Richter

Re: TM500 / 5000 Extenders

 

Link is useless, also Griessen's down below.

Re: TM500 / 5000 Extenders

Mlynch001
 

Dan’s extenders are an essential for any TM5xx owner or technician! These are tube best you can get. I have two and use them all the time.

--
Michael Lynch
Dardanelle, AR

Re: TM500 / 5000 Extenders

mosaicmerc
 

Very good product, pleased to have been a customer!

Ancel

Re: Tek 2235 Repair

Tony Fleming
 

I had similar problem and I was able to CLEAN the " beam find switch" fixed
all of my problems.
I have videos on my youtube here:
https://www.youtube.com/playlist?list=PLv52A7rm-UViZEOlzZfZOB9Gl8cjS3ze5
and scroll down to Tektronix videos. There are 4 or 4, you can
possibly learn something from it.
Let me know how is your "repair" going!

Harvey, thanks for helping me back when I had this problem!!!

Lastly, Merry Christmas and Happy New Year for you all!

Tony

On Sun, Dec 22, 2019 at 3:44 PM Harvey White <madyn@...> wrote:

For the beam to be centered, the voltage on the deflection plates (both
V or both H) has to be equal, that is, the two vertical plates must have
the same voltage. That's one thing to check. One thing that can happen
is that the beam find switch is sticky, or not making contact. However,
the first thing to do is to check all the power supply voltages, both
for voltage and for ripple.

In similar scopes, both the + and - supplies feeding the amplifier must
be correct.

The beam find switch reduces the gain in both channels, turns off a lot
of the blanking, and forces the trace to be more or less on the screen.
If any of the contacts are sticking, then you have a partially
implemented beam find, which can have all sorts of odd consequences.

Harvey


On 12/22/2019 2:23 PM, Oscar Anderson wrote:
Little update. I tried feeding in a signal, and when I push the beam
find button I can see some part of the signal. This is the case for both
channels. I will note that while I can move the "traces" around with the
vertical and horizontal position controls, it is through a limited range.
Images are attached.

It seems as though most of the issues people have with the 2235 are
power supply related, though as of right now I have no reason to believe
that the power supply in this scope has any issues.

https://imgur.com/gallery/zoGqxDQ







Re: Tek 2465 Problem

John Gord
 

Panos,

It is possible that the rectifiers are fine. Schottky rectifiers have a low forward voltage drop and relatively high reverse leakage. Depending on the test currents used by your ohmmeter, you might get the readings you found. You could run a test with a known forward current (100 mA or so) and see what the forward drop is, then run a test with a reverse voltage (5V or so) and see what the reverse leakage is. Then compare those results to the part data sheet.

--John Gord

On Sun, Dec 22, 2019 at 01:55 PM, Panos wrote:


On Sun, Dec 22, 2019 at 04:31 PM, Panos wrote:


because they have very low in ohm resistance (about 130 ohm) when I measure
these with forward polarity. Conversely they have a complete cut.
Sorry I must to said forward 80 ohm and conversely 2 kohm.

Re: Tek 2465 Problem

Panos
 

On Sun, Dec 22, 2019 at 04:31 PM, Panos wrote:


because they have very low in ohm resistance (about 130 ohm) when I measure
these with forward polarity. Conversely they have a complete cut.
Sorry I must to said forward 80 ohm and conversely 2 kohm.

Re: Tek 2235 Repair

Harvey White
 

For the beam to be centered, the voltage on the deflection plates (both V or both H) has to be equal, that is, the two vertical plates must have the same voltage.  That's one thing to check. One thing that can happen is that the beam find switch is sticky, or not making contact.  However, the first thing to do is to check all the power supply voltages, both for voltage and for ripple.

In similar scopes, both the + and - supplies feeding the amplifier must be correct.

The beam find switch reduces the gain in both channels, turns off a lot of the blanking, and forces the trace to be more or less on the screen.  If any of the contacts are sticking, then you have a partially implemented beam find, which can have all sorts of odd consequences.

Harvey

On 12/22/2019 2:23 PM, Oscar Anderson wrote:
Little update. I tried feeding in a signal, and when I push the beam find button I can see some part of the signal. This is the case for both channels. I will note that while I can move the "traces" around with the vertical and horizontal position controls, it is through a limited range. Images are attached.

It seems as though most of the issues people have with the 2235 are power supply related, though as of right now I have no reason to believe that the power supply in this scope has any issues.

https://imgur.com/gallery/zoGqxDQ




Re: TM500 / 5000 Extenders

 

Hi Gary,
I second what other members of the group are saying about the extenders made by Dan Meeks. They set a new standard for professionalism and for functionality. These are something even Tektronix would have been proud to offer. Unfortunately I think Dan may have sold all the ones he made. You might try contacting him personally to see if he has any plans to offer them again.

This is what Dan said at the time:

-----Original Message-----
From: "dnmeeks" [dan-meeks@...]
Date: 24/01/2018 10:15
To: TekScopes@groups.io
Subject: Re: [TekScopes] TM500 / 5000 Extenders

Hello group!
For anyone that is interested in these extenders, either fully built or parts, I ran out of everything from the Amazon orders. I'm sorry that I had to give the Amazon orders priority, but Amazon really takes the "ship within 3 days" seriously so I had to scramble to get those 20 built / tested / shipped.
For anyone that got one late, I'm sorry about that. I really had no idea that I would sell more than a few a month!
I have bought new PC boards and I have all parts on hand for another 20 - except for the 56 pin edge connectors, which are due by the first week in Feb.
If anyone has a source for that connector I could sell you everything else right now (either built up or parts). Otherwise, once I get those and finish up another batch of boards I'll be getting in touch with group members FIRST, then I'll put more up on Amazon after that. Several of you are out of the USA so I want to try to get boards shipped to you (Amazon is not set up for outside USA).
FYI - the new batch of boards I got with YELLOW mask... they look pretty cool but I am a little disappointed that the silkscreen (black) is not as easy to read. I have some of the blue boards left, but after that they will be yellow.
THanks again for the great interest in these. If anyone has any suggestions for changes, let me know. I am making small tweaks now for the next version (if I need more).
Or any other type of boards that people might like, I'm up for that, too.
Dan

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Gary Neilson
Sent: Saturday, December 21, 2019 6:49 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] TM500 / 5000 Extenders

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

Thanks
Gary Neilson




--
Dennis Tillman W7PF
TekScopes Moderator

Re: Tek 2235 Repair

Oscar Anderson
 

Little update. I tried feeding in a signal, and when I push the beam find button I can see some part of the signal. This is the case for both channels. I will note that while I can move the "traces" around with the vertical and horizontal position controls, it is through a limited range. Images are attached.

It seems as though most of the issues people have with the 2235 are power supply related, though as of right now I have no reason to believe that the power supply in this scope has any issues.

https://imgur.com/gallery/zoGqxDQ

Re: tektronix 7S14 batteries and time base question

Miguel Work
 

Best efficiency is obtained with long wavelength LEDs

Re: Tek 2235 Repair

n4mf@...
 

With the cover off and power off, make sure the deflection plates connections are still connected. I've run across a few with those just hanging in the scope.

Mitch
N4MF

Re: TM500 / 5000 Extenders

Greg Muir
 

I picked up a pair of Dan’s extenders during his initial offering (to service dual-connector TM500 modules). I have to say he has made an extremely professional product. If Tek or Tegam were still making TM5xx products they could have subcontracted with him without hesitation to handle his quality product.

Thank you, Dan!!

Greg

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!