Date   

Re: Tek power cables, older equipment

SCMenasian
 

This message appeared a couple of days after I made an eBay purchase of 5 1 foot long cords for $9.99+tax. I was aiming for the lowest possible cost. I figured 1 foot was the right length for me since my power strip would be under a foot from the back of the instrument. They are expected to arrive this week and I don't think I'll have any problems cutting them to size. A 575 Curve tracer will get one, A 067-0532-01 Constant Amplitude Signal Generator will get another. I even think I can cut one to fit the 2 prong connector on a 130 LC Meter.


Re: What to do with a tubeless 502?

Roy Thistle
 

Hi Wasteland Tek:
Such a cool name! I'm envious.
I must have missed the "unpleasantness in Portland?"
No.. there's a story to this one; but, I don't want to trigger the TekScope vigilantes so it will remain untold.
It's actually a 502A... I was thinking of some way to make it lighter so I could stack it.... or... suggestions?
Best regards and wishes.
Roy


Re: 475 questions

ciclista41@...
 

Hi Reed,

Yes, and it turns out you were right about that. I didn't do it, for the reasons that I had already decided to pull out all the large caps and replace them, plus I didn't see your suggestion until after I had done it. That's a diagnostic trick I would not have thought of, and I'll keep it in mind for similar situations in the future!

Bruce


Re: 475 questions

ciclista41@...
 

Graham,

I forgot to mention that I WILL be investing in a higher end DMM. While the GME-236, a recent acquisition, is quite handy for quick checks of ESR of in-circuit caps to find questionable or bad ones, It was fairly useless in checking the recent six big ones, as four were out of range and it only read one of the other two. But perhaps that was because the capacitance of the in-range one had fallen below its lower measurement threshhold. On the other hand, it would have been nice to know what the problem was rather than just getting no reading on that one. My most recent DMM, the Tacklife, I purchased because I was installing solar on the roof of my long, tall 2007 Sprinter van. Never completed that project, as major work on three houses got in the way. It's going to happen, as I had a remanufactured engine installed in it, and intend to hang onto it as a great utility vehicle as well as camper. I think the Tacklife is good for that and most house wiring, but by my definitions, that's electricity, and this scope is electronics. Different needs, obviously.

As for the error I made in that earlier post, it wasn't the first and won't be the last, but I did realize my mistake as I was thinking about it the next day. My fading mind substituted "Amps" for "AC", which of course makes no sense beyond both beginning with "A". It's current that must be measured in series, and that has nothing to do with whether it's AC or DC. I know better, but "wires crossed" when I wrote that. Not some kind of typo, just a dumb substitution. Thanks for the polite, gentle explanation, as opposed to the slapping my head that I did when I realized what I had done!

Bruce


Re: 475 questions

ciclista41@...
 

Thank you, Graham!

If you read the post I just made a few moments ago, you know you called the bad caps ahead of time! I just need to check the associated rectifiers. I don't think I should be turning the scope on with those six large capacitors out of the board, so unless I can figure out how to isolate the transformer or receive more advice on how to go about checking terminals 14 and 16 on the transformer, I think I'll hold off on that one.

Bruce


Re: 475 questions

ciclista41@...
 

Hi All!

I've been working on the scope and digesting information. I am posting this update before going through the posts that have been contributed since I last posted. Everyone has been really helpful and supportive. Thanks for making me feel welcome and for spending your valuable time helping me out!

I took the six large capacitors off the board today. Didn't go too badly, although two of the silver disk traces on the bottom of the board did come loose in the process. All those on the top remain intact. My new ZD-985 solder vacuum pump made the job MUCH easier, as even with solder wick dipped in RA rosin flux, I hardly got any solder out without the ZD-985. Still, I did need significant heat and repeated applications of flux even with the ZD-985. Access was made significantly easier by the removal of the trigger generator and Z-axis logic board (A8), which also went very smoothly.


All I have to measure these with is a cheap, battery powered AVR Mega 328 microcontroller "transistor tester", a GME-236 ESR meter, which has a range of only .47 to 2200 μF, and my Tacklife CM01a DMM for which all of these are out of range (.04 to 100μF). The "transistor tester", on the other hand, by far the least expensive of the lot, does 25pF to 100,000ΩμF along with ESR and "V-loss". I took the measurements using a couple of 4 inch leads inserted into the lever clamp, positions 1 and 3. Here are the readings, out of circuit, with each, although the 236 would not give me a reading for any but the C1412, even though the C1414 was in range. Below, OR indicates "out of range". IC indicates "inconsistent", where the 328 gave readings all over the place, but in the range of just under 0.2 to just over 3μF, so I'm guessing that the C1414 is the worst capacitor here. C1412 doesn't appear to be as bad, but if that ESR reading can be relied upon, it's pretty bad. NR indicates "no reading".

Rating (μF) 328 (μF, ESR Ω, V-loss %) 236 (ESR)

C1412 350 376.1, 6.7, 3.8 4.5 .04 to 100μF

C1414 1000 IC, NR, NR NR

C1442 5500 7411, .54, 1.6 OR

C1452 5000 6542, .61, 1.6 OR

C1462 5500 6499, .15, 1.3 OR

C1472 3000 3911, .19, 0.9 OR

I'm not sure what ESR ohms are acceptable for such large capacitance, but I'm guessing that even though the readings I got were excessive for measured capacitance, such low ESR values for C1442 through C1472 probably indicate that all but the C1412 and C1414 are reasonably good. Since I already have them all out, though, I think I'm going to replace all of them, unless the cost is prohibitive. I'd like not to have to go back in this part of the scope again. Part of the reason I took all of these out is that it's tricky to remove these, and as long as I'm removing one, I want to replace them all at once. Also, I took the advice of a couple of you who recommended them and sent for a set of the small, circular PCB's designed to accommodate more modern capacitors while preserving the job the aluminum cans did in connecting traces. I won't throw the ones that appear to be good out, though, at least until I get a reliable meter to evaluate them. They might still work elsewhere on a project where they will be more accessible and easier to deal with if they do go bad, eventually.

Having identified the bad caps, I'm assuming the next step is to check the rectifiers that feed them. Since these are much more accessible, I'll leave the good ones for now. I'll go back and recheck the advice I've received about checking them. In the meantime, I'm waiting for the circular PCB's and I need to order the large capacitor replacements.

Anything else I should do while I have the timing circuit board (A7) exposed? It appears to have two beige and one orange tantalum caps on it, although in the manual, all of these are identified as ceramics. So maybe my assumption that the brightly colored little blobs are the infamous tantalums is wrong. Lots more to learn! The orange is a 4.7μF and tests fine with my GME-236 ESR meter. Both of the beige 225 (I assume that's μF) ones test bad, although they don't appear to have any problem visually.

I did read a bit online about MLCC's vs tantalums. Apparently each has its advantages and weaknesses relative to the other. Are modern tantalums better? Or if we replace tantalums in these scopes with newer tantalums, do we get higher voltage tolerance ratings than spec to compensate? Sorry if this question has already been answered. It's been a couple of days and I need to reread some of your posts, as well as the unread recent ones.

Bruce


Re: Tek 4041 GPIB Controller

Dave Brown
 

Good news/info thanks, Monty
I'll dig my 4041 out and check what's there again-think I have some of those ROMS as well.
DaveB, NZ

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Monty McGraw
Sent: Tuesday, May 26, 2020 10:03
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek 4041 GPIB Controller

I see my attempt at formatting the directory listing didn't work :(

I captured ROM images from the CPU and all the Option ROMs back in 2000 when I bought my 4041, I'll be uploading those ROM images to my github repository later today.

4041 Program Development ROMs 1 and 2
4041 Graphics ROM
4041 Plotting ROM
4041 Signal Processing ROM
4041 Utility ROM #1

The Utility ROM has an interesting feature "PROM File System" and says the user can build a PROM from files on a tape. If the PROM contains an AUTOLD file, PROM0 will become the SYSDEV device to boot the system.


Here is a doc I wrote in 2000 about capturing the ROMs and what ROM carriers Tektronix used. Looks like I ordered some sockets and carriers - but I don't know where they are after all this time :(
--------------------------------------------------

TEKTRONIX 4041 OPTION ROMS – Oct 2, 2000 mcm

I got two Tek 4041 GPIB controllers. Both had the programming ROM set. One had four other option ROM sets: 4041R01 Graphics, 4041R02 Plotting, 4041R03 Signal Processing, and 4041R04 Utility – all labeled Version 2.1

The Option ROMs were in 24pin Molex Low-insertion force carriers P/N 8878 24-D, the ROM tray used Molex 8878 24S sockets. Neither of these parts could be found on an internet search. I went to the Molex website and found they still make 24 pin LIF carriers 50-39-5248 and matching sockets but I couldn’t find any in stock in internet electronics distributors. The 28 pin versions were in stock and around $2.50 a mated set at Carlton-Bates, so I ordered 6 sockets 15-29-9282 and 16 carriers 50-39-5288.

I used a Dremel to modify one 28 pin socket (pulled out two contacts at pins 13 and 16 and then Dremeled a groove on each side to accept the Tek 24 pin carriers. The carriers have one notch on the pin 1 end and two notches on the pin 12 end.

The Graphics ROMs were Motorola 68766C35 24pin 8Kx8 EPROMs.

Using my Data I/O Model 29B /w Unipak2 – Family 25/Pinout 29, I read each EPROM and transferred the data to the PC. Set Translation Format to 83 so they can be loaded into PC with DEBUG.COM HEX files can be loaded with DEBUG. TXT files are in the default Data I/O format 81.

‘Left ROM’ Checksum ‘Right ROM’ Checksum
Part Number Part Number
Graphics ROMs B020801 160-1755-01 96F5 160-1756-01 2071
Plotting ROMs B010807 160-1889-00 4D5F 160-1890-00 1938
Signal Procesn B010818 160-1984-00 4057 160-1985-00 945E
Utility #1 ROM B020781 160-2221-01 1034 160-2222-01 721B

The pgm dev ROMs were also 67866C35 EPROMs:

Pgm Dev ROM1 4041F30 160-1246-03 C533 160-1247-03 C915
Pgm Dev ROM2 4041F30 160-1335-03 7760 160-1336-03 EB34

The other 4041 had Pgm Dev ROMs version 2.0

Pgm Dev ROM1 4041F30 160-1246-02 C34E 160-1247-02 C250
Pgm Dev ROM2 4041F30 160-1335-02 5D6B 160-1336-02 C8DE


Re: Tek 4041 GPIB Controller

Monty McGraw
 

I see my attempt at formatting the directory listing didn't work :(

I captured ROM images from the CPU and all the Option ROMs back in 2000 when I bought my 4041, I'll be uploading those ROM images to my github repository later today.

4041 Program Development ROMs 1 and 2
4041 Graphics ROM
4041 Plotting ROM
4041 Signal Processing ROM
4041 Utility ROM #1

The Utility ROM has an interesting feature "PROM File System" and says the user can build a PROM from files on a tape. If the PROM contains an AUTOLD file, PROM0 will become the SYSDEV device to boot the system.


Here is a doc I wrote in 2000 about capturing the ROMs and what ROM carriers Tektronix used. Looks like I ordered some sockets and carriers - but I don't know where they are after all this time :(
--------------------------------------------------

TEKTRONIX 4041 OPTION ROMS – Oct 2, 2000 mcm

I got two Tek 4041 GPIB controllers. Both had the programming ROM set. One had four other option ROM sets: 4041R01 Graphics, 4041R02 Plotting, 4041R03 Signal Processing, and 4041R04 Utility – all labeled Version 2.1

The Option ROMs were in 24pin Molex Low-insertion force carriers P/N 8878 24-D, the ROM tray used Molex 8878 24S sockets. Neither of these parts could be found on an internet search. I went to the Molex website and found they still make 24 pin LIF carriers 50-39-5248 and matching sockets but I couldn’t find any in stock in internet electronics distributors. The 28 pin versions were in stock and around $2.50 a mated set at Carlton-Bates, so I ordered 6 sockets 15-29-9282 and 16 carriers 50-39-5288.

I used a Dremel to modify one 28 pin socket (pulled out two contacts at pins 13 and 16 and then Dremeled a groove on each side to accept the Tek 24 pin carriers. The carriers have one notch on the pin 1 end and two notches on the pin 12 end.

The Graphics ROMs were Motorola 68766C35 24pin 8Kx8 EPROMs.

Using my Data I/O Model 29B /w Unipak2 – Family 25/Pinout 29, I read each EPROM and transferred the data to the PC. Set Translation Format to 83 so they can be loaded into PC with DEBUG.COM HEX files can be loaded with DEBUG. TXT files are in the default Data I/O format 81.

‘Left ROM’ Checksum ‘Right ROM’ Checksum
Part Number Part Number
Graphics ROMs B020801 160-1755-01 96F5 160-1756-01 2071
Plotting ROMs B010807 160-1889-00 4D5F 160-1890-00 1938
Signal Procesn B010818 160-1984-00 4057 160-1985-00 945E
Utility #1 ROM B020781 160-2221-01 1034 160-2222-01 721B

The pgm dev ROMs were also 67866C35 EPROMs:

Pgm Dev ROM1 4041F30 160-1246-03 C533 160-1247-03 C915
Pgm Dev ROM2 4041F30 160-1335-03 7760 160-1336-03 EB34

The other 4041 had Pgm Dev ROMs version 2.0

Pgm Dev ROM1 4041F30 160-1246-02 C34E 160-1247-02 C250
Pgm Dev ROM2 4041F30 160-1335-02 5D6B 160-1336-02 C8DE


Re: Tek 4041 GPIB Controller

Monty McGraw
 

I made progress today and believe I have recovered all the files on my 4041 System Verification tape v 2.8.

Here is the 'long' directory for that tape:

<div>
SYSVER 2.8 29-APR-85 09:46:04 SOFT ERRORS = 0
FILE FILE LENGTH START NUMBER LAST
NAME TYPE IN BYTES RECORD OF REC. MODIFICATION DATE
------ ---- -------- ------ ------- ------------------
AUTOLD IT 2550 5 10 13-SEP-84 16:08:00
TERMIN IT 8160 15 32 13-SEP-84 16:08:00
SYSVER IT 3570 47 14 13-SEP-84 16:09:00
CONFIG AS 510 61 2 01-JAN-81 00:02:00
255
PROCED IT 1020 64 4 13-SEP-84 16:09:00
LINK IT 765 68 3 13-SEP-84 16:09:00
DISP IT 1275 71 5 13-SEP-84 16:09:00
KEYPAD IT 1530 76 6 13-SEP-84 16:09:00
PRINTE IT 765 82 3 13-SEP-84 16:09:00
TAPE IT 4590 85 18 13-SEP-84 16:10:00
SOFTER IT 765 103 3 13-SEP-84 16:10:00
IO IT 4590 106 18 13-SEP-84 16:10:00
255
TIMER IT 1530 125 6 13-SEP-84 16:10:00
PDKYBD IT 4335 131 17 13-SEP-84 16:11:00
GPIB IT 2040 148 8 13-SEP-84 16:11:00
GPIBLB IT 3315 156 13 13-SEP-84 16:11:00
GPIBCO IT 2040 169 8 13-SEP-84 16:11:00
SLAVE IT 3315 177 13 13-SEP-84 16:11:00
MASTER IT 1785 190 7 13-SEP-84 16:12:00
PAUS IT 765 197 3 13-SEP-84 16:12:00
TPCAL IT 1275 200 5 13-SEP-84 16:12:00
PTRCAL IT 1020 205 4 13-SEP-84 16:12:00
FRMAT IT 1020 209 4 13-SEP-84 16:12:00
TSTPTN IT 2040 213 8 13-SEP-84 16:12:00
CHKOPT IT 1275 221 5 18-SEP-84 13:04:00
OPT2 IT 765 226 3 13-SEP-84 16:12:00
HELP IT 3060 229 12 13-SEP-84 16:12:00
PDTEST IT 255 241 1 13-SEP-84 16:12:00
SCSI IT 2550 242 10 13-SEP-84 16:13:00
TSYSVR AS 4080 252 16 13-SEP-84 16:13:00
TSCSI AS 3315 268 13 13-SEP-84 16:13:00
TDIR AS 2295 281 9 01-JAN-81 00:25:00
94605
</div>

I posted the files I recovered on my new 4041 github repository:
https://github.com/mmcgraw74/Tektronix-4041-GPIB-Controller

I also posted the ASCII text version of all the programs.

I had issues with using the 4 1/4 inch Plastibands as DC100 tape drive belt replacements but got the verification tape files recovered.

I'm still having issues trying to use the LEMO keyboard connector to get into serial mode.

I recovered the .IT files with: COPY "filename" TO "COMM0:".
I got the ASCII versions of those files with: LOAD "filename", then LIST

I edited the * prompt character out of all the .IT and .ASC files

I'll wait for some smaller Plastibands that I ordered today to arrive before attempting to format one of my tapes and see if I can create a System Verification copy tape.


Re: Update on my 7854 diagnostics project

Ke-Fong Lin
 

Hi Holger and Dennis,

I'm already using PCBs as front panels for prototyping purposes:

https://drive.google.com/open?id=11nPji-pEWEQprJ6F2HMOWq0KOPtgqoQT

It's very cheap and convenient. I was rather looking for something not so "prototyping" and "internal" use.
Holger, it seems the minimum of one solder pad is needed for gerber drilling information.
Kicad is unable to generate correct gerber files if there's not at least one.

Shaeffer AG is well known but expensive. Another potential manufacturer is beta-layout.
I've never tried any of them.

Best regards,


Re: Belden Pressure Fit BNC

Wallace Gasiewicz
 

Dave:
That's what I thought also.
I was just intrigued by the compression fit, I really like the idea. I have been looking for such a fitting for a while.
Now there is one. Let me know if you try it. I might just invest in the tool and a few BNC connectors, but it would be nice to have some positive input on the device. I suppose going to really good RG 58 stuff might be necessary.
Wally KC9INK


Re: Tek power cables, older equipment

DaveH52
 


Re: Belden Pressure Fit BNC

DaveH52
 

You *might* be able to use it with RG-223 the center conductors are pretty close in diameter, but the additional shield increases the overall diameter from .195 to .210 so getting it onto the cable will definitely be a fight. Maybe you can drill out the inside of the connector compression sleeve to fit the coax better if you can find the just-right size drill bit.
I've got lots of RG58 that I use for my test equipment, so I'll probably get some to try out. I use compression connectors exclusively for my RG-6QS cable TV wiring because I find them easier and more secure than the crimp connectors, plus they're water-tight.
Dave - AC2GL


Re: Spectrum Analyzer

Jim Ford
 

Sad but true, Roy.

My 8566A/B hybrid, along with all the other great Tek, HP, and other test equipment I own would be in the dumpster immediately upon my demise (hopefully not for a while here since I'm *only* 55) if it were up to my wife and 16- and 14-year old sons. I've made my wife swear to me that she will contact TekScopes and the HPAK group and offer up said test equipment to the highest bidder or at least for a reasonable price (but not until I'm good and dead, mind you!) I trust you gentlemen (and a few ladies, too) to make reasonable offers.

Good idea for everyone on the list to do something similar to avoid dumpsterization upon their departures.

Jim Ford

------ Original Message ------
From: "Roy Thistle" <roy.thistle@mail.utoronto.ca>
To: TekScopes@groups.io
Sent: 5/25/2020 8:04:55 AM
Subject: Re: [TekScopes] Spectrum Analyzer

On Sun, May 24, 2020 at 02:01 PM, @0culus wrote:


The 8566/68 series of SAs
Hi Oculus:
Were talk'n to a guy here, who wants a 14 foot Lund, to go fishing on the pond... some weekends. And... recommending the U.S.S. Enterprise. The 8566/68 series of SAs... while I agree (if that's what you are saying) that the 8566/68 are probably the finest SAs ever made... they are a whole "another world" compared to something like a 1401A.
IME people who get these... cause the saw some edutainer, on YouTube, get results by twisting his tounge... well end up with something they only use to weigh down the garage floor... and the kids don't know, or care, what to do with it once dad has passed.
Best regards and wishes.
Roy



Re: TM50X transistors

 

jon,

we have tons of the real 151-0349 new parts in stock, see here:
https://www.sphere.bc.ca/test/tek-parts/tekparts2.html
they ship cheaply in a padded envelope.

regards,
walter


More Tek goodies on the Sphere Stuff Season page...

 

Everything from Tek 321A portables, probes and yes, more Tek knobs made it up today, along with lots of hp and fluke goodies. see it at: https://www.sphere.bc.ca/test/stuffday.html

I have some free working TM506R units for anybody that can use one, but they are big and heavy, so pick up is way better than shipping, in my personal opinion. Still a few free TM500/5K and 7K plug ins left to add to any order from stuff day as well. Need a 6 foot relay rack? have two to give away to anybody that can take them away, and no, we can't ship them.

Hope everybody is having an enjoyable and safe memorial day,
all the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.
https://www.sphere.bc.ca/test/index.html


TM500 Tester

Errick
 

From the April vintageTEK news letter "Another volunteer is developing an automated tester for the TM500 mainframes." Does anyone have any details on what is being done? I know the power module tester subject has come up many times in the past, and it will again.
I am/will/hope to build a tester soon.


Re: What to do with a tubeless 502?

WastelandTek
 

Is this one a victim of the recent unpleasantness in Portland?


What to do with a tubeless 502?

Roy Thistle
 

Hi All:
Well there's a story behind this one
I don't quite know what to do with it.
The CRT is there... most of the knobs (missing some from the blinding posts)... I think all the parts are there (I need to check better.)
It's in good shape... except for the carrying strap rot (no faux leather... just the spring steel... but, that's usually the case.)
Anyway... bulk isn't really a surmountable problem... but, weight is. I've already got a pile.
Remove the transformer and store separately?
Suggestions?
Best wishes all.
Roy


Type 502 Manual (weight and colour)

Roy Thistle
 

Hi All:
How much does a Type 502 Manual weigh... approximately... I'm guessing 1.5 pounds?
Also... I see some of them that are a dark green... and others that are the Tek blue... with a cutout on the front? ("showing 502")... and bound with those white plastic combs.
I thing the green ones a much older... are the blue ones legit... or photocopied and bound fakes?
Best regards and wishes.
Roy

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