Date   
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

scskits
 

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

Re: 602 (XY) CRTs

kc0wox Leeper
 

Here's some info on repairing 620's. http://golddredgervideo.com/kc0wox/tek/620/ It had a crt dot but it might help you.
Leonard

602 (XY) CRTs

toby@...
 

Hi group,

I'm refurbishing a 602 with no spot visible (with Z input driven at ~
1V). All LV voltages are good. Waiting for a high voltage probe in order
to do more checks.

I want to keep a spare CRT on hand just in case, and I'd prefer it to
have P7 or P45 phosphor.

I also have 634 and 604 here. Does anyone know the CRT compatibility for
the various 6xx family models? Ebay hasn't turned up a 154-0562-01 or
154-0572-01 yet, but if there is wider compatibility it would be
interesting to know.

Thanks for any guidance on 602 troubleshooting or CRTs.

--Toby

Re: 1502 TDR project - using bench supply

Tom Gardner
 

On 13/12/19 02:54, ehsjr via Groups.Io wrote:
On 12/12/2019 3:59 PM, Mark Pilant wrote:
So, here is a list of what I tried and whether or not it "worked":
    1)   Used the TekWiki cap/resistor replacement for the battery.  Did not work.
Two things come to mind on that.
First, do not attempt to power on the 1502 immediately after plugging
in the AC cord or wall wart supply.  Give it a few seconds to charge
the cap, then turn the 1502 on.

Second, the cap may be too small.  I used 4700uF which works
fine for me - I think the wiki recommends 2200.
The problem is that if the capacitor is too large it takes too long to charge up. The PSU interprets the low voltage as a failed cell, and shuts down.

The required C (and R) seems to be select-on-test, varying from one 1502 to another. Even if suitable values are found, it makes me wonder if it will switch on /next/ time :(

Re: 1502 TDR project - using bench supply

ehsjr
 

On 12/12/2019 3:59 PM, Mark Pilant wrote:
Success.
After using the bench supply, and giving the unit a couple of minutes to warm up,
I started rotating the intensity control. As I swept to the upper end, I could see
evidence of a trace, although off the CRT. By adjusting the vertical position, I
was able to finally see the trace on the CRT.
I decided to check a couple of RG-58 test cables I had laying around, and the TDR
got them right.
So, here is a list of what I tried and whether or not it "worked":
1) Used the TekWiki cap/resistor replacement for the battery. Did not work.
Two things come to mind on that.
First, do not attempt to power on the 1502 immediately after plugging
in the AC cord or wall wart supply. Give it a few seconds to charge
the cap, then turn the 1502 on.

Second, the cap may be too small. I used 4700uF which works
fine for me - I think the wiki recommends 2200.

Finally, if using an external supply (wall wart or otherwise),
put a diode in series between the supply and the cap/resistor
combo. The diode is to protect the 1502 against plugging in a
wall wart or supply with the opposite polarity, and protect "backfeeding" the wall wart or supply. The TDR tries to put
about 17 volts across the bananna jacks to charge the battery.

Ed

<snip>

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

 

On Thu, Dec 12, 2019 at 10:41 PM, John Griessen wrote:


must mean it is for eindhoven Netherlands. Tek had a factory at Heerenveen,
so maybe the customer was in eindhoven?
Dutch Philips' main offices were in Eindhoven.

Raymond