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Hi all, I noticed my 7A13 amplitude was way down on a 70 MHz sine the other day, so figured I'd run through the calibration. I skipped the input resistance section that requires the precision DC divider, and I'm using a PG 506 fast rise for the HF compensation; it's slower than the 250 ps Type 109 the manual calls for, but easier than messing with the Type 284. Through a 20 dB attenuator and 50 ohm thru termination, the 7A13 is showing about 1 div overshoot on a 5 division step from the PG 506, and I cannot adjust that out. It's so huge that I can't even see the effect of C113/C150/C250 on the corner. A bandwidth check with SG 503 says it's ~40-45 MHz. I've tried swapping the 1-2 relays that I haven't drilled and cleaned in this 7A13 with a NOS relay, with no change. It affects + input and - input alike (unused input set to GND), which has me pretty confused, as I thought the signal paths would be independent. Anyone encountered this before or have ideas on what to look at? Just as a sanity check, I tried a spare 7A13 that I'd never even plugged in, and it does not have the overshoot problem, and rise time is respectable (did not measure bandwidth because the SG 503 crapped out and started flashing 000). thanks, Adam

As many may remember, Walter Shawlee II passed away September of 2023. Since that time, his wife Susan, and children, have been busying themselves with the task of liquidating much of the electronic goodness that Sphere Research had accumulated. Susan intends to continue to make their collection of slide rules, nixie tubes and various other items available. Additionally, she is continuing in her effort to find homes for the remaining equipment. Please do visit Sphere’s site and help. Sphere’s inventory of Tektronix and HP parts has found a new home with us. We have the beginnings of a website (tekandhpparts.com), with the intention of continuing to make these parts available to the Tek and HP enthusiast community. A bit about us: 1) The goal of the website is to continue to make Sphere’s inventory available to the people like us that enjoy collecting, repairing and making use of these amazing examples of engineering and manufacturing. 2) A secondary goal is to “pay back” our retirement account of the funds used to buy the parts. It is truly secondary, and may never happen, but who knows? 3) We are retired, have three children, farm 20 acres of grass hay, tend to cows, sheep, horses and chickens, and have FAR too many hobbies and other responsibilities to have taken on another, but here we are…. 4) Our website is an amateur work in progress. Please read the home page posts for information on the site and on our progress. Tek items will be posted first, followed by HP and then “other” semiconductors and who knows what else. There is much awaiting inventorying, so if you don’t see the part you are interested in, please contact us directly (tom@...) and we will let you know if we have it. Look for announcements on the homepage as we complete the inventorying and pricing of each group of parts. Please be patient as we get the website, inventory and pricing figured out. Feedback is, as they say, a gift, so please share any constructive advice or suggestions for the site that you may have. The suggestion "You should have your head examined" has already been given! :) We can’t ever hope to duplicate the knowledge that Walter possessed, but will do our best to provide you with the right parts for your project. We look forward to getting to know our new customers, and will work hard to earn your trust. Thank you, Tom and Darla Norman

Looking at the Tek curve tracer models and schematics, I see that the actual requirements for the tubes are very modest. No high frequency performance is required, a flat face IS required, and HV potentials are LOW, so many tubes could be adapted to work. For example, in the 575, the tube has the dynamics (and pinout) of a readily available 5ADP1, but has the vert/horiz deflection on the neck. In reality, a 5ADP1 could probably be used there with 300 ohm twinlead bringing the deflection back to the socket. There is no geometry pin, but the 5ADP1 has good geometry to start with, so I think that is a doable conversion. In the 577 again the tube is not critical. A tube from a simpler low end 5K frame should be adaptable without too much grief, but the on screen gain might have to be adjusted. Again, the CRT is nothing special in terms of requirements, and there should be several possible subs with available 5K tubes. I would expect the lowest end 5K frames to be the MOST suitable organ donors. The 576 will be more complicated due to size and some odd CRT connections, but again, a low end 5K CRT should be adaptable, although the graticule and gun connections will be different. I don't have either of these here to experiment with, but I think these conversions could be done by most of the people here on the list, and should allow someone that really wants to keep their unit running in business. I am happy to try and assist anybody that wants to do it. all the best, walter (walter2 -at -sphere.bc.ca) sphere research corp.

My ancient Tektronix 547 oscilloscope with 1A1 plugin was working fine until a few weeks ago when the display suddenly went intermittent and bright, and an arcing sound came from the area of the crt high voltage circuit. No arcing could be seen anywhere, but the sound definitely came from the vicinity of the high voltage assembly. At this point, the Intensity control had no effect, and the intermittent sweeps were very bright. The sweeps only occurred when the arcing sounds were heard. Otherwise, a bright spot stayed on the left side of the display. The focus control also had only a slight effect. Suspecting the flyback transformer T801, I sourced an assembly from another 547 that included the transformer and the voltage multiplier comprised of the 5642 diodes. Symptoms remained the same, unfortunately. Replacing one of the regulator tubes in the 350V supply (6CW5) with a brand new one strangely made the arcing go away, but still no display. In fact, no more intermittent sweeps, only the ultra bright spot at the left hand side of the display. Currently, I have no way of measuring the high voltages from this assembly (10kV), so I’m not sure if they’re within spec. I also changed out the four 0.01uF caps in the Intensity circuit in case they were arcing, but no improvement. Scoping the output of the B Sweep Generator section (at tube V91), there was no sign of a sweep waveform (consistent with the stationary bright dot on the left side of the display). I’ve tested every tube in the scope, except for the 6080s (and checked all transistors for opens or shorts). None gave the impression that they would be show stoppers. I also scoped all B+ and B- rails. All were rock steady except for the +350V line, which had some ripple. Even after changing out the 6CW5, the ripple was still there. It’s obviously generating high voltage as evidenced by the bright spot on the crt. I can’t understand the relationship between the inability to control Intensity and Focus and the lack of a sweep signal. It doesn’t matter whether I’m in A, B or ALT timebases. Could the crt have an internal fault? Any advice or best guesses as to where I should look next would be much appreciated. Thanks in advance.

Came across some references & research papers online for the use of the Tek 7J20 RSS Spectrometer; .... might be of some interest: rick Tek 7J20 https://opg.optica.org/ao/abstract.cfm?uri=ao-15-11-2884 doi.org/10.1364/AO.15.002884 https://blog.everydayscientist.com/review-of-the-nanodrop-2000c/ https://vintagetek.org/rapid-scan-optical-spectrometer/ 7J20 NASA Pg. 75 https://ntrs.nasa.gov/api/citations/19770013602/downloads/19770013602.pdf NBS/NIST 7J20 Laser combustion of metals Pg. 19 https://nvlpubs.nist.gov/nistpubs/Legacy/IR/nbsir81-1647.pdf RCA 7J20 Pg. 13 ; … 45 (?) https://www.worldradiohistory.com/ARCHIVE-RCA/RCA-Engineer/1979-08-09.pdf RCA 4532a PD-Vidicon, AN-4623 https://www.one-electron.com/Archives/RCA/RCA-AppNotes/RCA%201973%20AN-4623%20Application%20of%20RCA%20Silicon%20Diode%20Array%20Target%20Vidicons.pdf DTIC 7J20 Pg. 26 https://apps.dtic.mil/sti/tr/pdf/ADA077412.pdf ** & many old posts on this Group, ...not necessarily titled accurately /g/TekScopes/topic/new_topic_outstanding/80215676 etc.

At the museum some of the volunteers would use a curve tracer to try and characterize and isolate faults. One of our volunteers used this concept to develop a low cost versatile debugging aid which we now sell. It is a two channel device that uses a weak signal to display two I-V curves on a windows PC. This allows you to compare various circuit elements and look for anomalies to help isolate an area for further investigation. We call this the Curvebug. Our web page has more information including a 9 minute video and the user manual. https://vintagetek.org/curvebug/ Dave

I use Google Translate. I don't have brightness adjustment and the reverse path of the beam is visible on my 2337. The A15 board is defective. A15 Vertical Output / H.V. Power Supply board. When I replace it with a working one from another 2337, everything is OK. Where should I "dig"? Thanks!

I just obtained a Tektronix 1240 Logic Analyzer from the Tektronix "RAMS" Store. I Was Reading the Tek Wiki on the Easter Egg Nothing Special but Here it is. https://youtu.be/x4248B81d2c Live Stream Initial Power Up https://www.youtube.com/live/33D8S3MGMEo?si=2qidUujGNStjHSyN&t=2358 Thanks

The following photos have been updated in the SC503 and SC504 Volts/Div and Time/Div Knob Shaft ( /g/TekScopes/album?id=302038 ) photo album of the [email protected] group. * photo-1.jpg ( /g/TekScopes/photofromactivity?id=3917517 ) *By:* Barry Breaux <groupsio@...>

I just picked up a 2465DVM from a TV station nearby, I have a few questions but I'm mostly looking for the rear feet/cord wrap that is supposed to be on this scope. The bottom parts of the feet are broken off, I suppose from being bashed around on a cart. Also, is it normal for the fan on this model to be loud, as if it's off balance? The 2445 I bought and got back working, the fan on it is quiet. Not so on this one. Naturally it doesn't have the original manual. I read somewhere there was a different fan put in serials after B050000 but I don't have the manual to see the schematic and part changes there.

Greetings from Louisiana! I have had several damaged shipments of the SC502, SC503, SC504 scopes. The Slope / Level switch-pot is damaged along with the knob. In a similar way the Volts/Div and Time/Div knobs were broken. In one case the shafts on all 3 knobs were broken. I decided to have shafts built in plastic and 316L Stainless steel. I took the original knob with the printed skirts and drilled out the original shaft and replace with the custom shafts I designed and had manufactured. The plastic shafts are as good as the original, and the 316L stainless steel shafts are far better than the original. I am also working on having the skirts manufactured out of 1/16" acrylic and printed with UV Ink. So now for the question(s)... 1) Does anyone have any SC502, SC503, SC504 knobs with broken shafts that need to be repaired. I can provide the shafts or repair your broken shaft. 2) Does anyone need new skirts for SC502, SC503, SC504. So far I have restored several of these scopes (more than 10). Initially I got plenty of help / suggestions from the group. Many thanks for that. Regards, Barry

I got knobs and Skirts for the SC502, SC503, and SC504s. The skirts came out perfect! See Photos /g/TekScopes/album?id=302038 Barry

Looking for the above

The following photos have been uploaded to the SC503 and SC504 Volts/Div and Time/Div Knob Shaft ( /g/TekScopes/album?id=302038 ) photo album of the [email protected] group. * IMG_2585.JPG ( /g/TekScopes/photofromactivity?id=3916678 ) * IMG_2587.JPG ( /g/TekScopes/photofromactivity?id=3916679 ) * IMG_2583.JPG ( /g/TekScopes/photofromactivity?id=3916680 ) *By:* Barry Breaux <groupsio@...>

Hi all, I have a Tek 2432 which fails the following; 1: 7000 CCD 2: 8000 PA 3: 9000 TRIGS I also have a Tek 2432A which fails; 1: 5000 WP 2: 8000 PA -- no pass/fail message 3: 9000 TRIGS -- no pass/fail message Is this an almighty going round in circles job or has anyone been through this before? Before you suggest it - the batteries are ok. I may donate these if they require a lot of time to fix to somebody who has the time. Regards Gearoid Loughnane Dublin

I would like to replace the graticule lamps in my 2465b. I thought I had seen a exploded view of the front panel assembly somewhere but can't seem to find it now. Any suggestions?

My TDS 380 finally quit, not be able to read the NVRAM anymore. I have removed the DALLAS 1655, dug out the battery, and attached an external 3V supply. It now saves the settings between power ups, so I assume the DALLAS part is working again. I obviously lost the calibration while replacing the battery. I have removed the calibration jumper on the main board, and run the voltage reference calibration, using a power supply, setting the voltage with the best that I have for a digital volt meter, using a voltage divider for the lower voltages. After the procedure completes I am told that the calibration has failed. Can anyone tell me why the 'scope indicates a failed calibration? I've also noticed that when I set the date, no month appears, just the year, date in the month, and the time. Thanks, Gary Appel

Not a big fan of Facebook (but I'm interested in Meta AI...so...) Anyway, this was posted, recently, in the "Vintage Electronic Test Equipment" VETE forum/group, on Facebook. Anyway... if it was me... and even though I'd like to get it... it's not going to be. I'd offer him a few bucks for it... especially if he has to USPS it. Remember, it's on Facebook, it in AR, and it's heavy. -- Roy Thistle

I have a 2465B with a broken Volts/VAR shaft and am asking for second opinion on replacing The shaft. My first thought is to pull the front panel out following service manual. Then proceed to the POT module removal process as described in service manual to Gain access to the broken shaft for removal from the actual variable pot. Install a replacement shaft, then reassemble everything. I have a dead 2465A for parts doner that I plan on practicing on first. Is there a simpler solution for what I need to do? After the shaft is replaced, I plan on recapping the LVPS and then replacing the surface mount electrolyte capacitors and DS chip on the A5 board.

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