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Re: vintageTEK new debugging aid
Here is another possibility for Linux/MAC...
There is a GPL'd version of the host software for the CGR101, a two channel scope that used to be sold by Syscomp Design: It's written in Tcl/Tk, which is an interpreter, and runs on Linux, Windows, and Mac. The CGR101 has a similar serial interface as the curvebug, and the host software already supports menus to auto-detect or manually select the right /dev or COM port. In operation, it polls the scope and plots the two channels, just like the curvebug. The host software supports a lot of other stuff in the CGR101 like function gen, pulse gen, and logic I/O, but that functionality can be removed, leaving just what's needed for the curvebug. It could be an alternate starting point for anyone who is interested in doing a Linux or Mac implementation. I think most of the work is deleting code. The above version on github is out of date. I have a newer version and can provide it to anyone who is interested, please PM me. I used to have a CGR101, but no longer. Syscomp Design is out of business, and their code does not seem to be out there anymore. They had a lot of devices written this way and provided the source to all of them. It's a shame if it's all been lost. -mark |
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Re: I got a working 2465B, looking for some advice.
On Sun, 18 May 2025 at 22:32, Jay Czaja via groups.io <jmczaja=
[email protected]> wrote: Is there anything else I can use as a substitute for the tunnel diode My limited understanding is that you need a 250mV rectangular wave with a risetime much less than that of the 2465. Leo Bodnar's step generator is currently the traditional answer, but I have not checked the amplitude/frequency is suitable for the 2465. If a 2.5V/300ps risetime into 50ohms is acceptable then you could - with care about the layout and decoupling - use 74lvc1g gates. |
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Re: I got a working 2465B, looking for some advice.
On Sun, May 18, 2025 at 02:32 PM, Jay Czaja wrote:
Well you could try a fast pulse generator based on avalanche breakdown of bipolar junction transistor... if you believe the specs. AFAIK... ideally you want a scaled delta function, to measure the un-attenuated (so mV range) transient response of the 2465B's vertical amplifiers -- Roy Thistle |
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Re: TEK 2465A Rebuild
Depends on what you mean by ¡°broke¡±, Luca. If you mean uh, yeah, it seems like it¡¯s working, then it could mean it¡¯s not broke. But it would be foolish to assume that something inside one of these vintage pieces we all love so much isn¡¯t in imminent danger of going kablooey. That could be another definition of ¡°broke¡±.
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Jim Ford Laguna Hills, California, USA On May 18, 2025, at 5:51?PM, Roy Thistle via groups.io <roy.thistle@...> wrote: |
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Re: TEK 2465A Rebuild
Hi Larry,
The battery I used was a LTC-7PN 3.5v 750mAH from eBay. I paid $25 with free shipping (US). Unfortunately the vendor is out of stock and there are many of this battery listed on eBay for ridiculous prices... also it's a Lithium battery, not a LIPO as incorrectly said above. If you were asking about the procedure to replace it, you have to keep at least 3vdc going to the ram chip that holds the calibration. If it looses power the calibration settings will be lost and the scope will have to be recalibrated which is not an easy job for most of us. I soldered the leads from a battery holder to on the back of the A5 PCB to the resistor and diode that go to the battery (see photo) , two AA 1.5v batteries supplying 3v to the ram chip while I soldered in the new battery. and then removed the AA battery leads. |
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Re: TEK 2465A Rebuild
Firstly, I want to say thanks to Steve for his good words, and clarify that his "Thank You" was unsolicited.
In this day and age, the simple words "Thank You" are generally considered surplus and unnecessary, and when someone does say "Thank You", it is considered unusual, and raises eyebrows - what's his ulterior motive? The opposite was true 50 years ago, and perhaps this "modern progressive" society might do well to come full circle again. Looking back over previous posts, I noticed that Vendors of valuable items are encouraged and welcomed - such as Ram's U800 replacement PCB from India. And why shouldn't we encourage and thank those vendors who do a really good job of enhancing the usability of our scopes? And, on the opposite side of the scale, we are not shy about calling out the charlatans - example - the fake 2465's with butchered 2445 PCB's from California. IMHO it's very healthy to air opinions or reviews of one's good or bad experience, as long as it is firstly Personal, and secondly Based on fact. Just my 2 cents! Menahem |
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7A13 overshoot
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 |
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Re: I got a working 2465B, looking for some advice.
Jay,
The resistors that are known to give problems are to Q1851, Q1852 and Q1890. Mouser part number for these are: 279-H4P150KFCA, 279-H4P180KFZA, 71-CCF60-332K-E3, 279-H4P430KFZA and (2 in series) 660-MF1/2CC2213F for R1853. For the 100meg: . See which radial leads fit in the original holes. Mark |
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Re: TEK 2465A Rebuild
On Sun, May 18, 2025 at 06:18 AM, Lawrance A. Schneider wrote:
From the Tektronix Documentation Eagle Picher LTC-7P Battery Non-Rechargeable,Rectangular, Lithium Thionyl Chloride,3.5 VDC,750mAh MFR Part #: LTC-7P RS Stock Number: 70141129 That's RS components (You have to search your country's RS Website yourself: they block links.) Note: (1) That is not a LIPO battery. (2) Replacing the battery, if done incorrectly, could lead to unintended consequences. (You can search TekScopes for the details.) -- Roy Thistle |
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Re: I got a working 2465B, looking for some advice.
Thanks. The CRT's brightness is fine. It's the focus that is soft and is most noticeable in the corners. I'll have a look at the schematic and get my bearings on where the focus resistors are and replace them and see if there's any improvement.
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On Sun, May 18, 2025 at 07:29 PM, Mark Vincent wrote:
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Re: TEK 2465A Rebuild
Luca,
You nailed it! Some things you know to redo because of age/known problems no matter if it works today or not. What works today can easily fail tomorrow. What you save today could cost more tomorrow. A way to think about this is would someone not change oil in their vehicle because it works today thinking they saved money and time saved was worth it then get mad tomorrow when the engine locks up due to too little oil. Mark |
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Re: I got a working 2465B, looking for some advice.
Jay,
You know by now to recap the piece as PM. This way, you know it is up to date and better quality condensers are installed. There are some resistors that should be increased in wattage.. Condoraudio has a great kit. There are some resistors not in his kit that should be there, yet. You can get the parts list if you want then order. It is best to mount the new condensers with a gap from the condenser to the board to allow for air flow and get a good solder joint on each side. As for the crt being weak/borderline, you can increase the heater voltage 20-30% higher for some minutes to see if that helps. This step is done without the scope being on, only a supply that is higher than 6.3V. If you have or access to a crt checker that is good to professional quality, you can check it. Crt checkers have different heater voltage selections so the previous step can be done with a checker. If weak, replace with a known good one. There are resistors in the focus circuit and a few on the high voltage board that are known to go bad to being overstressed. They are the ones from B+ to C and C to B on the collectors. Use 1W 1% types, get ones that are physically correct for 1W such as 4x10mm or so, to replace the 1/4W types. These resistors will go high/open making it look like poor focus or a weak crt. The 100meg 1/4W carbon on the high voltage board, replace! That will be way out of tolerance. Ohmite has a blue body radial type that will directly fit that is larger in wattage or you can get 1% 1/2W axial from Mouser. IF yours has a separate battery, use a Tadiran 2.4A/hr axial type. This is heavier in capacity than original and is cheaper. I had the old Dallas chip removed and a FRAM put in to eliminate the Dallas chip and battery. I had someone else do the work and programming since I am not set up to do programming. It was worth the cost in my case. Yes, replace the SMD condensers on the A5 board! Tantalums work well. You can increase the capacitance if you want. Keep the voltage the same. Make sure the A5 board does not have condenser electrolyte leakage from the originals. The noisy fan can likely be quieted by removing it then oiling it. Peel the label back to get to the rubber disc then remove the disc then oil well. Mark |
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Re: 2337 problem with A15 board
Problem solved.
HV Module U130 has defect and have to be replaced. New one is unobtainable. U130 made by me. I chose diodes 2CL77 20kV 5 mA 100Khz and 470 pF 6kV for the multiplier. The remaining diodes are also 2CL77. All capacitors are disk ceramic for 3 or 6 kV blue color. Has 13 input/output pins. They are made of brass, stuck in Teflon sleeves. So it can be soldered from the inside and outside. The HV coupling is made of Teflon. Low founding paraffin for pouring. It melts at about 70 degrees. In case of a defect, you melt it, pour it and repair it. It is great instead of epoxy resin. Measured voltages vs GND. CRT anode - 16000 CRT pin 1 - 1974 CRT pin 2 - 1974 CRT pin 3 - 2048 CRT pin 4 - 1544 CRT pin 14- 1976 |
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Re: TEK 2465A Rebuild
The "if it ain't broke, don't fix it" attitude kind of doesn't fly with these scopes anymore. I've opened three of these 24xx series scopes and each of them had their selection of either cracked RIFAs, worn out/leaking PSU caps, leaking A5 board SMD caps or the backup battery on its last legs.
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Re: Sphere's Tektronix (and HP) Component Inventory - tekandhpparts.com
Thanks Tom and Darla for helping Susan and the family to keep the inventory
of electronics available. I was a customer of Sphere Research for both slide rules and electronics for years. Whenever I bought electronics from Sphere, they would include a bag of ¡°bonus¡± parts - and it wasn¡¯t just junk. A lot of useful parts would be in those bags. I¡¯ll have a look at the website. I continue to look at the Slide Rule Universe both for information and the occasional check to see what slide rules remain. Regards, Steve Horii On Sun, May 18, 2025 at 11:23 Tom Norman via groups.io <jtnorman= [email protected]> wrote: As many may remember, Walter Shawlee II passed away September of 2023. |
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I got a working 2465B, looking for some advice.
I picked up a working 2465B locally for a decent price, at least much more decent than eBay prices. It has a lot of miles on it and has certainly been used (40k+ hours) but obviously not abused. Physically and mechanically it's is really nice shape. I also did some quick tests (horizontal and vertical) with a PG506 and TG501 and calibration still seems to be just about spot on. The scope was removed from a working environment and was was part of an equipment auction for employees of the company.
The only thing noticeable and bother me is that the CRT is soft which is not surprising given the number of hours on the unit and the fan is a bit noisy. Its serial number is >55000 and appears to have been assembled in the early 90s perhaps even 1990 since that's the newest date code I saw on the few ICs I looked at. The electrolytics on the A5 board haven't leaked and the NVRAM (1990 date code) is still working. I'd have to assume the NVRAM is living on borrowed time and needs to be replaced. I'll also need to take a look at the condition of the caps on the power supply boards and figure out if any are in need of replacement. I'd think with all the hours on this scope, a lot of the electroytics are going to be a little tired. Since I'd like to put a better CRT into the scope at some point, I'm assuming it wouldn't really matter if the calibration data is lost since it'd have to be recalibrated anyhow. I'm assuming the replacement NVRAM need to be programmed with some data before installation into the scope. Is the anyone out there willing to program one for me or any suggestions for a cheap programmer that would do the job? I read through the calibration sections of the service manual and while it looks daunting It seems doable. The only piece of equipment that I don't have is the Tunnel Diode Pulser (Tek 067-0681-01.) or the 15pf input normalizer (the normalizer looks trivial to DIY). Is there anything else I can use as a substitute for the tunnel diode pulser? or is there anyone in the NJ area that has one? I'm assuming it's be a good idea to replace the SMD electrolytic caps on the A5 pcb as well, even though they don't appear to be in bad shape. Jay |
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Re: Sphere's Tektronix (and HP) Component Inventory - tekandhpparts.com
Thank you, Tom and Darla, for taking on this monumental task!? Best wishes as you continue the Shawlee legacy.
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Jim FordLaguna Hills, California, USA On Sunday, May 18, 2025 at 10:23:57 AM CDT, Tom Norman via groups.io <jtnorman@...> wrote:
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 |
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Sphere's Tektronix (and HP) Component Inventory - tekandhpparts.com
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 |
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Want : Tek576 collector knob (366-1007-00/-01) set screw hole height
I am looking for someone to measure the height from the bottom of the knob to the center of the set screw hole. some dimensions on the qservice page. but not listed set screw height.
same knob used in 7L13 SA and some TM500 series plugins. ((366-1007-00-01)-set-screw-hole-height) |
Janky Steve's Stereo Service
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