开云体育

Many thanks Bob; I did already discover that my other Storage board had an absent W250 jumper so I took the initiative to disconnect the one on the board I'm actually using. It worked as it should so we're good to go! I wasn't sure whether there would be any other problem lurking if I made this simple change.

I've noted that while the V-mode cursors are actually present, the T-mode cursors are not visible, even though the system (the LED display) is actually responding to physical changes via the cursor control knob. I guess I need to probe around a bit to work out why the t-mode cursors are not visible..... probably something mis-adjusted.

Jose, we have several PS501, some with the meters, all works fine.

Open to your offer, we seek any TM500 plugins for swap or TEK 7000 plug-ins

Unis location in USA

Please contact with PM or emails

Bonsoir

Jon

Hi Jose,

Makes perfect sense. I have both models, and use both for different reasons. Having a built-in meter is definitely handy. The 503 has an LED whose brightness tracks output voltage, but unless you have a calibrated eyeball, you need a separate meter.

Good luck hunting!

--Cheers,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070

Hello Bob
Thank you for the reply and certainly you make sense.
But the odd reason for wanting the PS-501 is to have a unit that I can move around in a single rack without depending on an outtside meter
Makes sense?

Jose Orgnero

Why do you want a PS-501 as opposed to a PS503 or PS503A? Except for the built-in meter, the PS503 is superior, having dual +/- 20 volt supplies with tracking capability. The PS503A can supply 1A on the +/- 20 volt supplies when used in a high-power slot in a TM504 or TM506. The vintageTEK Museum has a number of PS503's and PS503A's and we could set up a sale.

--
Bob Haas

Thanks for the quick responses guys~!~ I checked with Artek earlier, he said the highest referenced serial number is B103xxx and mine is a bit higher, maybe not too high but higher. I’m going to send him a picture of the PCB and ask him to compare it with his B103 manual. His comments agree with your NFO, the latest he has is Oct. 1985. I don’t know when these two were produced; they came from Linn-Benton Community College in Eugene, Oregon. They appear to have sat ‘somewhere’ for quite a time, as some very fine dust has filtered into everything. Once I get these units O.R. I’ll need to do some careful switch cleaning. I just hope I’m not asking him too much from Artek…

Living here in Tek’s backyard so to speak, I’ve monkeyed with a lot of Tek gear over the years, (Starting in high school in 1969, fun story about Tek there but I’ll leave it alone) and I’ve never had a unit on the bench with so many shorted Ta’s. Between the 5440, the 5B48, and (so far) the 5A42’s, I think so far I’ve pulled a dozen. <Whew> I completely understand why some folks just R&R every single one of them, they appear to be a ticking time ‘cap’ just waiting to go off, or short as the case appears to be. Funny question, how would you know if one opened? Yeah, a good idea to swap them all out~!~

There are two versions of the vertical preamp board. The older one has dual pots for vertical position, the new, single-section pots. I've uploaded this picture: /g/TekScopes/album?id=274014

Depending on the version of vertical board, a jumper may or may not be required at the location shown.
--
Bob Haas

I ordered mine and it was delivered a couple of days ago. I am very happy with it. As a Tektronix enthusiast, it is a pleasure to just see this lit up in my shop. I consider this an "accessory" to my collection and am very glad to own one. I appreciate John creating these and sending a portion of the proceeds to the VintageTek Museum.

Just a happy customer....

Elsewhere I have recently discussed my 468 repair project. I now have an analog scope working pretty much correctly. However the digital store function seemed to have problems of no display.

I discovered that both V & H were offset from the visible screen. After some probing I thought I had discovered a problem with the Vrefs on the A16 board and replaced U559 and tested it out of the scope on a bench supply, but imagine my surprise when I bolted it all back together to find the Vrefs were down again; instead of +/-7.5V the +Vref was ~5V and -Vref according low.

I then discovered that the Vref problem disappeared when I unplugged P262, or BOTH of P138/P343 on the A11 V preamp board. According to my schematics, the V-shift "ghost" pots should be floating and connected ONLY to the A16 board via P138/343, when in fact both the ghost pots appear to be already attached to +5V and GND on A11 and delivering a shift voltage to A16 within that range. Thus the A11 is over-riding the A16 Vref voltage.

Have I got some incompatible A11 & A16 boards in my scope?

The scope serial number is 710418, but I would not be surprised if any of the boards came from other scopes and may not be contemporary.

Scanning through the sevice manual I see two different configurations in the pre-amp boards which explains the affore-mentioned issue but the question is what should I do to fix the problem?

The short answer might simply be to remove the offending connections and leave only the slider connections intact. I have in fact just experimented and plugged P138/343 onto A11 using only the connector centre pins (ie I've plugged them in at 90 degrees) and the system actually works (well for V mode cursors... not yet got T-mode cursors visible).

The A16 has a model number of 670-6377-02. I have a newer board version 670-6377-06 in a parts mule; might this be a better solution..... not sure whether that board actually works because the mule has a number of functional issues.

Any suggestions out there?

Your basic part number for the manual is correct, but you need a later version. The 5A48 did go through several modifications over its lifecycle. And the commonly-found manuals on the internet are valid only for some of the earlier versions. I would suggest you get in touch with Dave Henderson at Artek Media. I believe he has scanned versions that were written as late as Oct1985 or so.

Best Regards,
Neil

This topic is now on moderation - Templeton's posts have been deleted.

David (moderator)

"Mak[ing] replacement or custom acrylic graticule inserts for various tek scopes" has value to Tek owners.

Your further point about 'all money in your pocket' remains false by inspection.

Again you don't appear to have read the post. I did.

Please stop this.

EJP

Michael as far as I have seen the technical manuals follow the pattern 070-XXXX- 00/01/02....
But I do have one model early unit that does not match the early manual.
Jeff

--
Jeffeelcr

I did find one with an SPST switch in stock at Digikey for $9.64 plus shipping. Somewhat surprisingly to me, they have 757 in stock. Mouser is out of stock and quoting 23 weeks lead time!
Since my scope is in the US and wired for 120 volts, not 240, it's not really necessary to disconnect both sides of the AC line from the power transformer, only the hot side So this one will do unless I can find the correct one.

I need a 311-340 pot (50 ohm with DPST switch) to fix the graticule lights on my 564. It's open, and won't come apart ("hot-molded" case).
25-30 years ago I would call Deane Kidd. RIP.
I'll message Pam but does anyone on the group have a spare?
thanks.

Evening folks, I've got a 5440 on the bench equipped with a 5B42 and a pair of 5A48 modules. I soon discovered that the pair of 5A48 modules is a different flavor from the common manuals circulating on the Internet. The serial numbers on the modules are nearly consecutive and both modules are well over B100000, all the service manuals I've found so far are part number 070-1450-00, Rev B, 1974. I don't have the part number for the correct manual and I'm wondering if anyone knows what the correct manual part number is for the later serial numbers, and further, would they have a .pdf of it. <Grin>

So far. the 5440 has been brought back to life and the 5B42 module is back up also, sans many Ta caps. The 5A48 still needs attention but my unit is substantially different than the module featured in the 070-1450-00 manual. Any help would be appreciated~!~!~

Best,
~Michael - AF7U

On Sun, Apr 3, 2022 at 03:39 AM, David Templeton wrote:

Nothing to do with fixing or being used on scopes

False.

just all money in your pocket

False.

Did you read the post? I would like to thank John for his work and I am discussing an order with him now.

EJP

On Sat, Apr 2, 2022 at 10:55 AM, John Perry wrote:

I was asked by several members to post these here. Not to just spam my
business in any way. "just all money in your pocket" I think not. I barely
make anything on these with the time involved and donations to vintageTEK. If
this offends people in this group the Moderators can delete the post and wait
to learn about these in the vintageTEK month newsletter.

John, I would like to publicly thank you for your efforts. As far as I am concerned, your efforts and products benefit the Tek cause and the Museum and they are appreciated. Gordon

Update from my post in 2020. When I put my instrument's caps on a bridge, C91 and C94 (made by Erie) read like polyester, while C92 and C93 (Sprague 160P "DiFilm" paper/plastic) have appreciable Dielectric Absorption, which shows up as increasing C as F is reduced. When I replaced C92 and C93 with modern plastic-film caps, I found that I overshot the mark - where the 130 previously read high at the low end of the scale, now it reads low at the low end of the scale. Just a bit, enough to annoy me. It was not due to polypropylene, I stuck in a polyester and there was no perceptible change. I decided to make a first-order simulation of olde-tyme paper DA by shunting the cap with a series RC. Using a substitution box I groped around for a sweet spot. I found one for C92 (.0047uF, 30pF range), 470pF + 470K. YOUR MILEAGE WILL VARY. The time constant t is 0.22ms which in a filter transitions at 1/(2 * pi * t) = 0.72kHz or about mid-scale frequency.

Low/mid/high readings with 11.3pF Cx.
Before: 11.5/11.8/12.5
After: 11.5/11.0/11.5

I could not get enough improvement on C93 or C94 to bother, but I was able to help C91 (.0015uF, 100pF range) with 220pF + 150K.

As you can see by the pictures at TekWiki, when Tek started making the 130 in 1959, they built it with paper-oil "Bumblebee" caps which had more DA than polyester even when new. As time passed, the Purchased Item Source List (PISL) changed the various part numbers from paper to paper/plastic and then full plastic, but the meter scale was still tooled for paper.

On Sat, Apr 2, 2022 at 08:04 PM, Jon Harrison-Hughes wrote:

Ignore that, it turns out I hadn't seated the ribbon on the CPU board
correctly, all working again :)

Hi Jon,
I just sent you my PM reply. Your gesture does deserve mention on the forum though.
Your gesture of making copies of the instrument's ROM images and sending them to me is very much appreciated, to say the least. In my instrument at least, the ROMs were soldered in, making it that much more special if it's the same in your unit. And that after so much time! I'm a bit busy at the moment, with a few big beasts on my desks so I must do some planning before diving into this instrument that I would like to be functional again.
And I'm happy to hear that your problem after re-assembly was mostly a false alarm.
I'll keep you posted!

Kind regards,

Raymond