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Hi all. Can't seem to find these anywhere. According to Sphere, these are, 'HARD to find 49xP Series Inverter Transistors! - 2N6587, TO-61, NPN, 10A/450V' - (SOLD OUT) Is these a feasible request, or shall the 492 be stripped and sold for spares? James

I recently purchased a Tek 561A oscilloscope and determined that there is something wrong with the timebase plug-in. I followed the troubleshooting guide in the manual and determined that there is something wrong with the horizontal amplifier and the normal sweep generator (according to the test points for these parts of the plug-in the voltages are way out of spec) any insight onto what the issue would be would be greatly appreciated

I just got a Tek 468 from one of the guys here in town. It's missing the back cover and feet. Does anyone have what I need to put my scope back together? Just the parts or an old junker would be great. I have a photo, but I don't know how to attach it here. Thanks! Mike Harmon, WB0LDJ mharmon at att dot net

Hi All, I am in the process of alignment after an extensive repair process of a very clean 2232. I have several questions, hopefully some answers:- 1. Does the rear right side, PSU section get quite hot, fan and air flow is not impeded and is working as intended, PSU voltage and ripple values work as documented, only -5.0 is sitting at -5.38 W9020? 2. Does anyone have a better understanding on the (13. adjust acquisition position offset (R7325 and R7335) when in test mode as documented on page 103 in section 5.10 of the SM? The Digital card must be in the service position to gain access to R7235 and R7335, this may present some alignment issues and position(s) of on screen lines, but happy to be corrected on this? Thank you in advance. Regards Gerald VK3GM

I recently acquired a Tektronix 2246 oscilloscope. It seemed to be working fine until I opened it and tried to check the test and self-calibration voltages (some of which out of the limits, but it is the same before and after the issue happened). Now no text is displayed, and the Readout intensity knob makes a dimmer version of the trace show up above it. If I try and open the Service Menu, etc. the screen just turns blank but I am able to quit out of it by pressing the right button. Photo in /g/TekScopes/album?id=300837 Any suggestions for how to fix this? This is my first time repairing an oscilloscope, so any pointers would be appreciated. Thanks for your time.

Hi All, I have been working on a 2782 unit with questionable freq. and amplitude correction data making the unit not usable at the moment. I have managed to get a working extension and serial IO card that gives me full keyboard service command control and feedback via trace mode, this allows me to look and store via screen dumps all correction data, good or bad. I am reluctant to take the next step using time consuming manual commands and measurement setup to try to align FM narrow/freq. and amplitude correction data. Does anyone have any prior knowledge or has worked on a 2782/4 in a past life? My next step is to work through the manual Cal process and document all steps and what I have achieved along with all data/sw. Now that I have a serial card and extender card working 100%, I may produce a bunch of extender cards with integrated serial interface to be made available if there is interest. Any feedback is welcome. Kind regards Gerald VK3GM

Hi All Anyone know what the correct voltage is at the input of L6 on the Power Supply. Its the supply circuit for the display CCFL. I'm getting -4.6v. My display is a dull shade of orange with no detail. A new display did not fix it. The output CCFL voltage is reading 768v pk-pk. Manual says is should be 1270v pk-pk. The other power supply voltages are correct.

The following photos have been uploaded to the SC503 - interesting waveform! ( /g/TekScopes/album?id=300884 ) photo album of the [email protected] group. * IMG_2525.jpeg ( /g/TekScopes/photofromactivity?id=3890274 ) *By:* Barry Breaux <groupsio@...>

Hi Everyone, I am in the process of reverse engineering 2 PCB:- 1, the 278x processor Serial IO PCB 2, an extension card 3, look at the s/w Bob has provided, can it be used under DOS. Lotus 123 and Lotus measure with 2 x GPIB control will be a challenge. Bob Koller was generous enough and provide me on loan several PCB to reverse engineer. I am starting another directory (2782 HW & SW service info) and this will contain all relevant data, schematics etc that I work through to resolve an issue with a 2782. I would also like to reach out to anyone who may have any additional schematics or any information on the 2782/2784. I have a unit with late revision PCB, some schematics do not appear to match. For example the A29 PCB 100MHz) ref source PCB in my unit it is a 670-9461-07. The bottom side of the PCB has an alternative schematic (no ECL). Regards Gerald VK3GM

Hi Guys, I am trying to fix some problems on my 11302, but I am stuck on a problem that seems very simple, but which I cannot overcome: a simple voltage divider. I am probably doing something wrong, but I cannot guess what (I added an album among the photos with the simplified schematic diagram). The 11302 "reads" the CRT cathode voltage using a voltage divider, selected by a 4051 analog multiplexer. It should be simple: the voltage divider is made up of a 20 M ohm and a 20 kohm resistor (the former is actually 2 x 10 Mohm resistors). So the output should be one volt for every 1000 volts in the input (well, 0.999). For me this is not the case: the divider output is significantly higher than it should be (with -1.6 V in the output, the input is actually -1.510 V). Easy, you say, one of the resistors has changed its value over time, but it is not so. I desoldered one extreme of them and they are all very precise. Another hypothesis was that the CRT mesh was causing some problem, but it is not: I disconnected it and nothing changed. I neglected the C1100 and C1420 capacitors because they could only lower the voltage, not make it greater. The last thing I didn't check yet is the dirt on the lower part of the board, but before disassembling it I wanted to hear your suggestions, if you like. I will be very grateful for any help, I am getting crazy. Thanks Gianni

Hi, it's me again... :) I was going to go on with the 11302 checking and tried to connect to TekCATS 2.19, but in the meantime I had updated the firmware to the 3.1 version and TekCATS refuses to connect to it. Has someone a more recent version of TekCATS or must I reinstall the old firmware?

Hi all, So last year my venerable old 2465A developed a weird intermittent fault. After some time - arbitrary and not temperature related - this fault would arise whereby the screen would become *really* bright with some spurious artifacts showing up as well. When this happens, the screen brightness control fails to have any effect and I cannot turn that dazzling brightness down. Now, from what I've read, I need to monitor TP73's voltage ('grid no. 1' to the CRT) and see if it changes when the fault arises. So I've stripped the casing away and removed the HV safety/warning shield from the HV supply board A9 and attached a scope probe to TP73. The service manual provides a diagram of how the waveform on TP73 should look so I'm all revved-up waiting for the fault to materialize (which it invariably does when I try to use it to check anything). Guess what? I've had the damn thing on now for 5 hours and it's not missed a beat! Behaving perfectly normally with no sign of any screen issue at all. Bloody intermediate faults. I hate 'em!! Jinxie

Hi. I have a HP54502A in fairly good condition I want to fix for my workbench. It fails on A/D test (pass D/A and rest) on CHANNEL 2 only. I have no schematics, just the SM, and if anyone knows of link to any it would be appreciated. Anyway, have anyone else successfully fixed this error before and what was it? I did see a blog online with at short in PS but ALL voltages seems OK and 5.2 adjusted according to SM. I have swapped the 2 ICs with heatsink around just to eliminate that. In lack of a schematics does anyone knows which IC is the DAC (A/D converter) so I at least can have a look around it and compare channels (CH 1 works perfect). Any hints are welcomed......... PS. the Dallas chips has been replaced before I got the scope with a DS1230Y so guess that is not the reason? I got the schematics for a 54601a is that too far off or similar in chip sets used? Cheers

Hello, I have a Tek P6248 differential probe, on which the micro wires in the head have unfortunately broken off. Unfortunately, the pinout of the wires, or the "Cinch" plug, is no longer recognizable and I haven't found anything online, even though this seems to be one of the most common problems with the probe. https://1drv.ms/f/c/a3cea52fd4e3ee5e/Ql7u49Qvpc4ggKM_AwAAAAACGN3PbgU5dBZXAw Perhaps someone here can help me. Best regards, Eric

Hi everyone, Yesterday, while working with my Tektronix 2465, I suddenly heard a strange noise from inside, followed by a very unpleasant smell. There was no smoke, and the trace was still visible on the screen. I immediately turned it off and haven’t tried powering it on since. I suspect it might be a Rifa capacitor gone bad, but I need to inspect the boards to be sure. After removing the cover, I realized that I can’t clearly see how to remove the A2 (Horizontal) and A3 (Vertical) boards. My main question is: Can I remove the A2 and A3 boards without taking out the A1 (Main Interface) board first? Or is there another trick to access them more easily? Any tips or advice from those familiar with the 2465 would be greatly appreciated! Thanks in advance!

Looking into a 465 S/N B260137 and trying to determine what seems to be causing the additional trace in background of triggered wave forms. Power supplies all look good for voltage and ripple. Suspecting trigger board but exactly unsure. Any thoughts would be welcome Added photos to album : 465 Scope with Ghost trace Craig

Hello I am at a standstill with figuring out why the CRT of my 2465A is blurry and won't focus. I purchased this unit from Government Planet last summer with the idea that I would probably have to troubleshoot it. I turned it on and it made a screeching sound and had no display. I thought the sound was coming from the fan but no it was the high voltage board. Checked the voltages on J119 and they were all good with the exception of the -15V rail which had high ripple. Decided to recap the LVPS with a kit from Condor Audio. This fixed the -15V rail. Turned it on and there was a blurry dispay but intermittent screeching from the high voltage board. Looked closer at this and discovered that the ceramic of T1970 was cracked in several places. Purchased a new high voltage board from QService and installed it. Now no screeching but the display remains blurry with the Read Out letters wider and taller than they should be and the same for the traces. I have uploaded 2 pictures to the file Amberwave 2465a that shows what I'm talking about. I checked voltages to the CRT socket at pins 8(31V), 12(-108V to -186V) and 13(-192V to -224V) and they look reasonable. DAC reference is right at 10V. When I input a signal into the scope I can just make out that it is a sign wave. I just don't know where to go from here. I have invested a lot of time and dollars in this scope to just give up. It would seem that this isn't a HV board issue as both boards gave a blurry image. Could this be the CRT tube itself or one of the IC's? I would really appreciate some guidance on where to go from here from someone more experienced with these scopes than me Rusty Hilliard W0RGH

Hello people of TekScopes, I have a Tektronix 7B92A that needs repairing. It has a very severe horizontal deflection off to the right of the display, but the sweep is also jittery and not stable. I've probed the sweep generators and I've confirmed they are not the problem as the sweep waveforms are beautiful. I'm pretty sure the problem is in schematic No. 6, the output amplifier for the plug-in. The only problem is, this part of the circuit is on a section of the A6 main board that is under the A7 logic board. Because of this I can't reach any of the points I need to test. I've tried removing the logic board and probe the A6 board that way, but that stops the plug-in from sweeping, which is useless for testing points on the output amplifier. I could just solder a tiny wire to every point I need to check and do it that way, but some of the points I need are on socketec transistors and I don't want to risk solder filling up a socket. Any tips? Benjamin

Just a quick one which might help anyone whose scope boots fine but then has no display.. Obviously there are several reasons this might happen, however whilst working on one of these last week, this problem was created by a faulty U950, Z-Axis Hybrid chip. 155-0242-00. Swapped the chip and the display came back perfectly. James

Gianni Becattini <Giovanni.becattini@...> added the photo album Bewitched voltage divider (11302) ( /g/TekScopes/album?id=300803 ) : see my emailò