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I have been working on a 2245 for a while that has multiple issues but this particular problem is stumping me as it's become clear I don't really understand how the Z-axis/Focus circuits in this unit actually work. I started with no horizontal and traced that to Q805 being shot. Those FETs are pretty rare so I replaced with a "best I could find" substitute that got the horizontal running. I have since found a source for the FETs and can replace with correct replacement once I finish the other debug. With the horizontal working, it became clear that the scope seems to be running at max intensity and the controls on the front have little to no effect on the intensity level. It's so bright that it is "blooming" and defocusing what might otherwise be a sharp display. The FOCUS control has some effect but only to defocus it more. There is no in-focus point that the control can reach. I've done many of the measurements on sheet 7 and most are pretty good and within tolerance except one, At the emitter of Q2708, I measure -0.18v rather than the spec'd +0.18v so that is suspicious. However, I do not understand how the circuit ahead of that-- including the testpoint 7B is supposed to work. I can actually disconnect this circuit, by opening W2701, and with that disconnected, there is no change in the display. Everything is still at max brightness and everything is still visible on the display-- trace and readouts. I've tried putting some voltage into the external Z-axis input, also without getting any change in the display. I've measured the outputs of the op-amps U1001, which the front panel INTEN pots control and there is full range of swing on the outputs of these op-amps. So, the knobs and the followers after them appear to be working. So, I'm looking for some guidance on how the circuit just ahead of testpoint 7B is supposed to work? eg, what purpose do Q1001 ... Q1004 serve? Some kind of bias maybe? Or, the Z-axis circuit in general as my problem might be around Q2708 or Q2712/Q2713 ... I put a photo of the display here, /g/TekScopes2/photo/302416/3915732 You can see what I think is the retrace of the readout "drawing" since the intensity is so high or there is lack of blanking. Thanks for any input! Chris -- Chris Elmquist N?JCF

https://www.ecosensory.com/tek/tek-fuses7A29-maybe.jpg

Hi people, I want to read a DS1644 with the T48 programmer and Xgpro software but can't select the DS1644. Only the 12xx variants are available. Do these also work? Or is there different software to use with the T48?

I like this series of scopes, so was drawn to a 2230 (100 Mhz digital storage) at a low price. The seller said it lit up but he couldn't figure out how to run it. Well neither can I - in it's present condition! I haven't used the storage models of this series before but after skimming the op and service manuals, what appears to be happening is, something is forcing the digital side to run one of the "exercisers" every time on power-up. For the first few seconds after the beam becomes visible, I can see normal traces that respond to controls (if you're quick about it) which indicates the analog side is working. But then the screen changes to a pair of concentric boxes and center axis lines. The inner box can be moved from side to side with the horizontal position control but that's the only control that has any effect. Nothing other the cycling power will make this display go away. My best guess is that this is the "Box" exerciser display that would normally be enabled by pressing one of the Menu Select/DISPLAY buttons during power-up. If so, then it would seem that something is doing so unintentionally - i.e. a defective switch or a failure in the circuitry attached to it. I can see that a "stuck switch" would cause the instrument to run the Box exerciser, but it normally should be possible to exit the exerciser by pressing one of the other buttons, which doesn't happen. I looked for a schematic of the front panel board in the service manual but didn't find much. Is additional documentation on the 2230 available? If I can get it working I'd use it mostly in the analog non-storage mode. Thanks for any suggestions!

While going through another crate of Tektronix gear I came across this board, which has the legends "GPIB", "TEK T1", and "R-0291-XB". My google fu might be weak but I can't find any hint to the board's use or origin. Anyone recognize it? Here's a link to the photo: https://www.dropbox.com/scl/fi/7g8yxs2uy8vssnegli0ka/K7WXW-GPIB.jpeg?rlkey=q8333no7z0l761n7jpk6kwcht&dl=0 Thanks - Bill

Hi all, I'm currently looking for a suitable Tektronix oscilloscope for a specific use case: Displaying vector graphics in XY mode from arcade PCBs (Atari Asteroids, Tempest, Space Duel, etc.) – ideally with clean beam blanking via the Z input. I'm also planning to use it for general CRT repairs and TTL logic diagnostics. I'm trying to find the “sweet spot” – the best break-even point between technical capability, reliability, and low maintenance. I know these scopes are way overkill for my use case, but I have a soft spot for well-engineered, high-end analog gear from that era. Important to know: I'm not an electronics engineer – I'm a computer scientist by trade. So robustness and low maintenance are my top priorities (right after a proper Z input). I’d prefer something that just works and doesn’t immediately turn into a restoration project. My key criteria: Z input with true beam blanking → Not just brightness control – I need actual blanking to avoid ghost lines between vector points. Low maintenance, long-term reliability → I’m leaning toward models without battery-backed NVRAM (e.g., EAROM in the 2465). However, I’ve read that there are now precalibrated NVRAM replacements without batteries. → What's your take? Is the newer 2465B (with NVRAM) still the better choice long-term – or is the older but potentially more robust 2465 a safer bet? Good CRT (brightness and focus) → I don’t need MCP – in XY mode, I prefer full screen size over extra brightness (so 2467B might be a step in the wrong direction for me). Technical condition over bandwidth → Anything in the 100–300 MHz range is more than enough. I'd rather have a stable, well-maintained unit than an ultra-fast one on paper. Right now I’m deciding between the 2465 and 2465B, but I’m open to other suggestions from the late 22xx or 24xx series. Also: if anyone here happens to have a suitable unit available – I’m definitely open to offers. I’m located in Germany, but happy to discuss shipping if needed. Thanks in advance for any insights or recommendations! Best regards, Christian

Hi there, I have fallen heir to a Tektronix 453 scope. From appearances it appears to be fairly clean and complete - with one exception: The rear cover is missing, which exposes the back end of the CRT, the fan and other goodies. Might any of you have the back cover from a 453 that could be purchased? If it would help I can send a picture of what I don't have, or better put - a picture of the back end where the cover is supposed to go so you can hopefully see what's missing. Thanks, Burt, K6OQK

Chris Elmquist <chrise@...> added the photo album 465B pack panel : wanted to show the connectors and labeling on the back panel of a 465B, specifically to get the specifications for the Z-axis input The following photos have been uploaded to the 465B pack panel photo album of the [email protected] group. 465B-back-panel-connectors.jpg By: Chris Elmquist <chrise@...>

<https://www.mill-max.com/products/new/zero-profile-press-fit-receptacles> Cheers, David

2465B s/n 57xxx When I first powered it up, the lights would all come on for a split second, then they would go out, then it would cycle through the self-tests, failing at TEST 05, so I cleaned up the A5 corrosion and replaced a few components there. I also replaced the RIFAs on the power supply. Following that, when I turn it on, the lights all come on, but they don't go out. All J119 points are well within spec. I am a little confused at times when following the service manual, for example the troubleshooting procedure said TP201 should be +10v, but the schematic seems to indicate it should be +5v, which is what I'm getting. I'm not sure how to proceed at this point. I'd like to go as far as possible before I am forced to buy a new oscilloscope to repair this one. Thanks

I've recapped a 2465B and replaced a faulty U800 with a RU800, ran through cal OK except for one thing. It seems that at fast sweep speeds e.g. 5ns, the X axis is distorted appearing compressed to the far right of the waveform. You can see an image here (100MHz sine wave applied to Ch1) : https://peardrop.co.uk/IMG_6199.jpeg Has anyone seen anything like this, or have an idea what may be causing it? - Keith

Hi, Anyone know someone who can rewind HV transformers? Lost my beams on my 561. Thanks

Hi all, I got this scope in non-working condition due to failures of the A10 module (acquisition board). First time I turned it on, it ran and failed its startup tests. Since then, though, it'd start successfully and only fail full tests if ran deliberately (of course) - I think this is because this has been sitting for a long time and I gave it a bit of a run and that's been baking for it and reforming caps and so on, so a good thing. Always, the failure is apparently associated with the acquisition board. I don't recall if the forum allows image attachments to emails, but if it does, I'll send some logs and reports shortly. The failure seems to be associated with different ICs on this board every time I run them. Not sure if that can be interpreted conducively in any way. Thank you for your input in advance! Radu.

I sent this the other day to the other TekScopes list but thought I would try here too for more ideas. I was given a 2245 recently which of course doesn't work too well. Investigation reveals that Q805 and Q806, in the horizontal right plate output stage, are cold to the touch. The service manual, section 6.2 (page 6-19) says, The MOSFET output transistors (Q801 and Q802 left plate-- Q805 and Q806 right plate) run hot. If either side is cold, it is defective. So, that's me and now I need to find a couple of these VDMOS FETs, which seem to have become quite rare. They are Tek P/N, 151-1211 VN1316N2 N-Channel VDMOS FET, 160V, 250mA, 40 ohm 151-1212 VP0116N2 P-Channel VDMOS FET, 160V, 250mA, 25 ohm Has anyone solved this problem with a modern replacement pair? and have suggested substitutes? These are in TO-39 package which adds additional challenge but I suppose TO-220 or equiv could be made to fit. Of course, the real thing would be great too if there is a source. Thanks for any leads! Chris -- Chris Elmquist

I am still cleaning up and ran across a 1980 Tektronix Catalog, a 1981 Tektronix Catalog, a 1980 HP Catalog, and a 1981 HP Catalog. All are hard covers. The are free if you pay the shipping costs although I would gladly accept and appreciate donations!

Hello again Have a working Tek SA 492, SN B05 1984 , 2500 hrs. to check power supply for RIFA caps, lytic and tants, the. PSU remove procedure in manual is vague on the location of connectors before you pull it. Any tips or diagrams ? caps to replace or change ? Your thoughts and advice appreciated Many thanks Jon

It occurs to me that, if I am going to unbind my 7934 manual (re-binding is a pain) to scan pages 6-22 and 6-23 in order to update the copy on TekWiki, it would be useful to know if there are any other pages missing from the online copy. This would require someone to go through the online manual page-by-page to verify that those two pages are the only ones missing. I don't have time to do that right now. If someone is willing to do that, please let me know ASAP. DaveD KC0WJN

Due to a mistake on a drawing Tektronix had 012-0482-00/01 cables made with RG-58/U cable. They have now corrected the error and have the 012-0482-00/01 made with RG-223/U cable. -- Jeffeelcr

Hi all, I'm one more of those people who can't pass by when they see the shape and colors of something Tektronix. Now I'm working on a 2467B and while it seems to be working well, there was one thing I wanted to resolve before finishing my calibration efforts. It's a late model I think; some date codes are from 1995, the serial is B053790. I started measuring the test waveforms from the service manual (070- 6863-01) in the trigger, sweep, horizontal amp and Z-amp sections (reson below). What I am confused about is that several sweep gate and sweep waveforms initially look okay on my scope but I don't see the same levels. And looking at the schematics, the test waveforms don't make sense to me. Waveform 31, for example, is supposed to reach -0.2V. But I assume U700 outputs 0V or 3V on the SG# pin, and Q745 cannot pull it lower than GND. What does? CTO by charging the "** part of ECB" capacitor?! I normally work in the digital domain and I always struggle with these analog things. For the B trigger, waveform 38 is easy, it's just 0V or 3V on SG#. But then waveform 39 follows and quite unexpectedly drops down to - 0.5V. Again, the PNP transistor doesn't seem to explain that. These A and B "sweep gate not" signals are interconnected and also enter U985 and U975 (the "measurement PAL"). The latter seems to get pretty warm, but I see no obvious malfunction. I read the circuit description on page 3a-21 of the manual but it did not give me an answer. So any help making sense of these waveforms is greatly appreciated! As for the reason for looking into this, I had some difficulties doing the "high drive focus" and "writing rate threshold" adjustments on page 5-6 of the manual. Triggering seemed unstable, although this might be normal (the manual talks about a "flashing sinewave"). Later I noticed that at fast sweep times, something like 2 DIV of the trace seemed to be missing between the triggering edge and the start of the trace on the display. An explaination was given on the other list [1] about how this is expected behavior due to propagation delay in digital logic and I can actually see the triggering edge, thanks to the delay line. I'm attaching some screenshots/pages from the manual for the reader's convenience (or at least I'm trying). - Michael [1] /g/TekScopes/topic/11350057

Wondering if anyone who has a "spares" 465, 475, or 485 would be willing to pull a couple of the LEMO power jacks from the back (the four pin jackused to power Tek probes that use +/-15VDC) for me. I want to build a stand alone power supply so I can use some of my power-required probes on my 2465B, which aren't equipped with them. email is K7WXWatqrpdxdotnet or message me here. Thanks! Bill