Date   
Re: Great video for 500 series Tek restorers

Kurt Rosenfeld
 

Lazyelectrons has continued the series of videos on the Tektronix 555. There are five of them up now. The latest is here: https://www.youtube.com/watch?v=A0-rZohmyjQ

Highly recommended!

-Kurt

Re: DC-508 repair advice

Mlynch001
 

Check your fuses on your plugins. They are prone to open when the pass transistors fail. Also check your voltages as well. Plugin crowbars are also prone to fail. Pay special attention to the complementary transistor in the plugin I.e, the one that’s mated to the failed pass transistor. For example, in a TG501 on the 15v Supply, this would be Q610.

--
Michael Lynch
Dardanelle, AR

Re: DC-508 repair advice

radioconnection@...
 

Well, thanks to the advice, I did find bad pass transistors, and a few plug ins seem to have some issues. This is turning into a larger than expected project. Those mainframes are miserable to work on!

Re: Paying it forward with David's Part's Exchange

Lawrance A. Schneider
 

Hi,

I have a: on the front RTD710/A - ADAPTER
on the back L9A-0450-00
671-1194-00

Looks to be some sort of parallel connection going from internal connections to outside connections. I see a lot of what appear to be terminal resistors. Not a very good description I know but...

If someone wants it, let me know. Just pay postage.

I see there is a spreadsheet of parts. If you would like, add this to the list and show my name as the contact point.

larry

Re: DC-508 repair advice

Carsten Bormann
 

On Dec 14, 2019, at 16:14, Mlynch001 <@mlynch001> wrote:

On the TM503 check your pass transistors. My TM506 had 4 bays out of 6 that had very weak or outright "bad" pass transistors. They will wreak havoc with your plugins.
And one problem is that some plugins are damaged by bad pass transistors, and these very plugins then proceed to break the pass transistors of the next slot they are in.

These things need condoms.

Grüße, Carsten

Re: Paying it forward with David's Part's Exchange

Tam Hanna
 

Hello,

let me join in by mentioning that I usually have at least one order from Mouser a month, and also have a working billing relationship with AliExpress.


If anyone of you ever wants to "ride" me and my wife, we are always glad to be at service. But sorry in advance, we are not fast.


Tam

--
- - - - -
With best regards
Tam HANNA

Enjoy electronics? Join 13500 followers by visiting the Crazy Electronics Lab at https://www.instagram.com/tam.hanna/

Re: Paying it forward with David's Part's Exchange

Mlynch001
 

David,

Very Generous of you. You have inspired me to consider doing something similar for those on this forum.

--
Michael Lynch
Dardanelle, AR

Does anyone have any PIC17C42A-16I/L to spare (ideally in UK)

 

Extended temperature range PIC17C42A version in PLC44 ...

Thanks David

Re: Paying it forward with David's Part's Exchange

EricJ
 

Very nice of you David, kudos.

--Eric

On Dec 14, 2019 11:18 AM, David Berlind <david@...> wrote:




Hi Tekkies...

I have launched a Google Spreadsheet that I am very slowly updating with
the inventory of all my parts. In an effort to pay it forward to you and
others that have been so generous in helping me to get my fingernails
dirty, I'm making 99% of the parts available to anyone for free.
Personally, it drives me nuts I need one part and I have to pay more to
buy it in bulk, or the shipping costs more than the part itself. I will
never use most of these parts and so I'd rather give them away (not in
bulk). All I ask is that you send me a self-addressed stamped envelope (or
other packaging) and I will put the part in that packaging and return it
to you. It's going to take me months to get this spreadsheet fully up to
date. Maybe years. I don't know. But each week, I'm chipping away at the
iceberg, adding new parts. So, let me know if you see something you need
or like. I'm calling this David's Part Exchange. Let me know if you have
any questions.
https://docs.google.com/spreadsheets/d/1Q4M7dnS--TXb5PW1VqEBmM2Sxonknz0vVFVk_rfho_o/edit#gid=437389817






Paying it forward with David's Part's Exchange

David Berlind
 

Hi Tekkies...

I have launched a Google Spreadsheet that I am very slowly updating with the inventory of all my parts. In an effort to pay it forward to you and others that have been so generous in helping me to get my fingernails dirty, I'm making 99% of the parts available to anyone for free. Personally, it drives me nuts I need one part and I have to pay more to buy it in bulk, or the shipping costs more than the part itself. I will never use most of these parts and so I'd rather give them away (not in bulk). All I ask is that you send me a self-addressed stamped envelope (or other packaging) and I will put the part in that packaging and return it to you. It's going to take me months to get this spreadsheet fully up to date. Maybe years. I don't know. But each week, I'm chipping away at the iceberg, adding new parts. So, let me know if you see something you need or like. I'm calling this David's Part Exchange. Let me know if you have any questions. https://docs.google.com/spreadsheets/d/1Q4M7dnS--TXb5PW1VqEBmM2Sxonknz0vVFVk_rfho_o/edit#gid=437389817

Re: DC-508 repair advice

Mlynch001
 

TM504. excuse me. Anyway, check them out, they can cause all sorts of issues.

--
Michael Lynch
Dardanelle, AR

Re: DC-508 repair advice

Mlynch001
 

On the TM503 check your pass transistors. My TM506 had 4 bays out of 6 that had very weak or outright "bad" pass transistors. They will wreak havoc with your plugins.

--
Michael Lynch
Dardanelle, AR

Re: DC-508 repair advice

radioconnection@...
 

It's working fine now... the transistor fixed it; but I was a few bucks on the ECL chip replacement.

Next project is a TM-504 auction site special.... BOTH 18,000 uF filter caps are open! ESR=infinity.
508 is in a good TM-503 for testing.

Re: DC-508 repair advice

Ed
 

Make sure that Switch S1380 (section 13) is turning ON when selecting the prescaler. Measure 5V on U1570B pins 6 and 7. I just repaired a DC502 that had the prescaler select switch switch stuck in the ON position (which disabled the prescaler), maybe the lever arm for this one is stuck OFF.

Re: DC-508 repair advice

Mlynch001
 

Sometimes the very simple things are the issue. My TYPE576 was knocked out buy a single 2N3906 that failed. Good luck with your repair.

--
Michael Lynch
Dardanelle, AR

Re: DC-508 repair advice

radioconnection@...
 

Q63 a 2N3906 level converter was bad...

Re: TG501 Option1 Oscillator Y50 needed.

Mlynch001
 

THANK YOU!

--
Michael Lynch
Dardanelle, AR

Re: Mylar Tektronix photos from 1950’s and 60’s fro eBay

Greg Muir
 

Given dimensions are in inches I suspect that the autopositives and the one negative were for use at the Beaverton plant. The indication of a Netherland reference on the negative may have been for a batch of completed panels destined to be shipped to their offshore plant for final assembly.

Photo anodizing is a significant process to maintain and I suspect that the Netherlands plant may have not possessed that function. Manufacturing processes requiring large overheads are usually located a one central plant with the lower cost manufacturing, mostly assembly related, being distributed to other locations when desired. Assemblers are a much cheaper commodity.

Greg

Re: TG501 Option1 Oscillator Y50 needed.

 

Hi Michael,
I can send you one I took out of a 7K plugin.
Contact me off line at dennis at ridesoft dot com.
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Mlynch001
Sent: Friday, December 13, 2019 8:44 AM
Subject: [TekScopes] TG501 Option1 Oscillator Y50 needed.

I have a TG501 with Option #1 and I need Y50 5Mhz Oscillator which is TEKTRONIX p/n 119-0262-00 or 119-0503-00. These are also used in 7xxx series plugins and other TM5xx plug ins as well. I have looked at the usual sources, including Sphere's online catalog and E-Bay as well, no luck so far. Does anyone have an extra unused part that they would be willing to sell? I would be more than happy to pay a reasonable price and shipping to anyone who might have one. I would prefer an item located in the USA, but would consider anything that is offered. I can pay through PayPal.
I have also read a couple of posts regarding this part and discussion about using some very common 10Mhz OCXO part to replace it. I am not 100% clear on how this is done, ISTR this involved using a 5V regulator to step down the 15V to 5V and rewiring the U50 divider to divide the 10Mhz down to 1 Mhz. Dennis Tillman touched on this in a post, I believe regarding a TM5xx series counter which he improved the performance of, using this method. I am not as experienced as Dennis, so what seems obvious and simple to most is somewhat more daunting to me. I would also consider this route, if I could get some more details, possibly a schematic, pictures and a BOM?

Thanks to All!
--
Michael Lynch
Dardanelle, AR




--
Dennis Tillman W7PF
TekScopes Moderator

TG501 Option1 Oscillator Y50 needed.

Mlynch001
 

I have a TG501 with Option #1 and I need Y50 5Mhz Oscillator which is TEKTRONIX p/n 119-0262-00 or 119-0503-00. These are also used in 7xxx series plugins and other TM5xx plug ins as well. I have looked at the usual sources, including Sphere's online catalog and E-Bay as well, no luck so far. Does anyone have an extra unused part that they would be willing to sell? I would be more than happy to pay a reasonable price and shipping to anyone who might have one. I would prefer an item located in the USA, but would consider anything that is offered. I can pay through PayPal.
I have also read a couple of posts regarding this part and discussion about using some very common 10Mhz OCXO part to replace it. I am not 100% clear on how this is done, ISTR this involved using a 5V regulator to step down the 15V to 5V and rewiring the U50 divider to divide the 10Mhz down to 1 Mhz. Dennis Tillman touched on this in a post, I believe regarding a TM5xx series counter which he improved the performance of, using this method. I am not as experienced as Dennis, so what seems obvious and simple to most is somewhat more daunting to me. I would also consider this route, if I could get some more details, possibly a schematic, pictures and a BOM?

Thanks to All!
--
Michael Lynch
Dardanelle, AR