Re: Tektronix 577 curve tracer not working properly
Do you have a normal looking trace??
Those two pots are in very different parts of the circuit. R1245 seems to set intensity, and R528 is in the horizontal offset circuit.
Maybe give us some more info about the operational state of the machine - what are the symptoms?
Thanks
Dan
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Tektronix 577 curve tracer not working properly
Hi all,
i bought a month ago a tek 577 with a few fixtures, tested a few times and it was working but was a little out of spec, so i’ve dediced to do a little calibration and found out that 2 trimpots weren’t working (the R1245 and R528 ).
Ordered some linear ones on digikey and replaced the 1245 one, now when switching the vertical/div from mA to lower ranges the protection light turn on (the dot gets greatly out of range), i don’t believe it was the 1245 that i’ve replaced maybe the preamp in the 177 or the amp inside the 577? I don’t have much time testing all the components, do you have any idea? In addition the 200 volt line on the power board is at around 218v…
Thanks in advance
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I have this scope here and it is doing weird things. First thing is when the Diagnostics are run, it displays a couple errors. "Processor" displays Result 114 with 1 Failure Count. "Acquisition" displays Result of 331 with 2 Failure Counts.
When each individual channel is turned on by itself, each appears to work OK. But if more than one channel is on at the same time, it gets screwy. With Channels 1 and 2 on at the same time, it will not display Channel 2; it only displays the Channel 1 input. Any channel will only be displayed if the trigger input is set to a different channel than the one I want displayed.
Any ideas about what the trouble is or what I should do?
Zack
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There's a ton of them on eBay.
Burt, K6OQK
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On September 11, 2024 6:22:53 PM PDT, "Eric Boyle via groups.io" <k0elb@...> wrote:
The Tubestore has them for $20 each. That’s not a bad price.?
https://www.thetubestore.com/6gm8-ecc86
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The Tubestore has them for $20 each. That’s not a bad price.?
https://www.thetubestore.com/6gm8-ecc86
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I don't know of any equivalents for the 6GM8 or ECC86. It's a special dual triode designed to run at very low plate voltage and the maximum quoted in the datasheet is only 30 volts. If you have a tube tester that goes down that low you could test it but I would worry about damaging it if the tester applies too much voltage. If the scope is functioning with the tube installed that's a better test than a tube tester anyway.
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Unfortunately it's prized by the audio community so prices on the e place are quite high. The only other Tek item I know that uses it is the type 81 plug in adapter that lets 530/540/550 plugins to be used in 580 series scopes. If you really need a replacement you might have to grit your teeth and pay the price :-(
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Morris
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Are there substitutes for this tube ?
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I che3cked mine on a TV7 tube tester and got 0 reading for transconductance
test. I thought the TV7 manual had wrong settings but I think its right.
?
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Regards, Dana.
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Re: Tektronix 2465A CT issues
Understood. So if you didn't do anything except take it apart and then reassemble it.
The most like issue is a cable that is not on right.
Very difficult to diagnose that over messages.
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Also, the diagnostics flowcharts in the SM will be of little help for such a problem.
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Re: Tektronix 2465A CT issues
Hi, I didn't recap, everything is original.
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-------- Original message -------- From: "victor.silva via groups.io" <daejon1@...> Date: 9/3/24 4:06 PM (GMT-08:00) Subject: Re: [TekScopes2] Tektronix 2465A CT issues
Jorge has a 2465A, so no need to worry about SMD caps failures.
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Jorge --- one quick question. Did you by any change pull off all the caps and then recap using the service manual as a guide?
There is a mistake in some service manuals that reverses two caps.
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Re: Tektronix 2465A CT issues
Jorge has a 2465A, so no need to worry about SMD caps failures.
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Jorge --- one quick question. Did you by any change pull off all the caps and then recap using the service manual as a guide?
There is a mistake in some service manuals that reverses two caps.
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Re: Tektronix 2465A CT issues
Hi Richard,
The LVPS?
Thanks, George
Sent from my T-Mobile 5G Device
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-------- Original message -------- From: "Richard via groups.io" <richard@...> Date: 8/31/24 12:45 AM (GMT-08:00) Subject: Re: [TekScopes2] Tektronix 2465A CT issues
Hi George,
The issue you show on the YouYube video is power supply capacitor
failure. Both my 2465's had this problem.
Richard
On 29/08/2024 22:22, Jorge Andrade
wrote:
I posted this on the EEVBlog's gigantic thread but have
gotten no replies, hopefully I'll get some hits here:
Hi all,
I'm also a "happy" owner of a 2465A CT. I was having issues
with the display jumping all over the place:
So I took it apart to recap the boards, but then I decided to
put it together so I could get the CAL constants before
recaping the boards, however, now I get an error message and
no traces and the LEDS above the display (LOCK-SRQ-REM) don't
light up:
From your experience, did I re-connect something wrong (maybe
a connector backwards?), or did one of the boards go bad? I
wasn't having any other issues before other than the display
jumping. The manual says TEST 05 FAIL 24 is ADD Main Board -
Positive Level is not Positive Enough. I didn't touch the High
Voltage Power supply or the board that's underneath the
O'scope, originally I only removed the 2 boards from inside
and the one on the side with the NVRAM battery. Any help would
be greatly appreciated!
Thanks,
George
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Re: Tektronix 2465A CT issues
Hi George,
The issue you show on the YouYube video is power supply capacitor
failure. Both my 2465's had this problem.
Richard
On 29/08/2024 22:22, Jorge Andrade
wrote:
toggle quoted message
Show quoted text
I posted this on the EEVBlog's gigantic thread but have
gotten no replies, hopefully I'll get some hits here:
Hi all,
I'm also a "happy" owner of a 2465A CT. I was having issues
with the display jumping all over the place:
So I took it apart to recap the boards, but then I decided to
put it together so I could get the CAL constants before
recaping the boards, however, now I get an error message and
no traces and the LEDS above the display (LOCK-SRQ-REM) don't
light up:
From your experience, did I re-connect something wrong (maybe
a connector backwards?), or did one of the boards go bad? I
wasn't having any other issues before other than the display
jumping. The manual says TEST 05 FAIL 24 is ADD Main Board -
Positive Level is not Positive Enough. I didn't touch the High
Voltage Power supply or the board that's underneath the
O'scope, originally I only removed the 2 boards from inside
and the one on the side with the NVRAM battery. Any help would
be greatly appreciated!
Thanks,
George
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Re: Tektronix 2465A CT issues
Merci!!
Sent from my T-Mobile 5G Device
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-------- Original message -------- From: "Froggie the Gremlin via groups.io" <jonpaul@...> Date: 8/30/24 1:56 PM (GMT-08:00) Subject: Re: [TekScopes2] Tektronix 2465A CT issues
More....test 05 fail 24 applies a mains low voltage sine to the trigger hybrid input The fail certainly indicates a mistake in connection probably at CT option board or failed trigger hybrid. See manual for test fail codes. Notice that the options are in a separate service manual Also the 2465A is different than the 2465B Finally see the A5 board type TH or SMD check for leaking SMD lit ICs and dead RAM backup battery. Bon chance Jon
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Re: Tektronix 2465A CT issues
More....test 05 fail 24 applies a mains low voltage sine to the trigger hybrid input
The fail certainly indicates a mistake in connection probably at CT option board or failed trigger hybrid.
See manual for test fail codes.
Notice that the options are in a separate service manual
Also the 2465A is different than the 2465B
Finally see the A5 board type TH or SMD check for leaking SMD lit ICs and dead RAM backup battery.
Bon chance
Jon
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Re: Tektronix 2465A CT issues
Bonjour monsieur
Have many 2465/7/A/B some with CTT.
Recommend
1/ post photos not video of symptoms, boards, etc
2/ post on both tekscopes2 and tekscopes, not the same
3/ get complete service manual for the exact type, options and serial number rangs, see W140, bama , etc.
Artech published excellent hard copies of the Tektronix manual
4/ follow trouble shoot flow chart
5 / see equipment list for full CAL
6/ check cables at edge of main board that connect at lower corners of CTT option board, easily overlooked
Bon chance
Jon
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Tektronix 2465A CT issues
I posted this on the EEVBlog's gigantic thread but have gotten no replies, hopefully I'll get some hits here:
Hi all,
I'm also a "happy" owner of a 2465A CT. I was having issues with the display jumping all over the place:
https://youtu.be/g6iKEVwqY9M
So I took it apart to recap the boards, but then I decided to put it together so I could get the CAL constants before recaping the boards, however, now I get an error message and no traces and the LEDS above the display (LOCK-SRQ-REM) don't light up:
https://youtu.be/q4gS29u1FuY?si=lmVH3ULfq2Pwa76U
From your experience, did I re-connect something wrong (maybe a connector backwards?), or did one of the boards go bad? I wasn't having any other issues before other than the display jumping. The manual says TEST 05 FAIL 24 is ADD Main Board - Positive Level is not Positive Enough. I didn't touch the High Voltage Power supply or the board that's underneath the O'scope, originally I only removed the 2 boards from inside and the one on the side with the NVRAM battery. Any help would be greatly appreciated!
Thanks,
George
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-------- Forwarded Message --------
With the shutting down of analog TV, is
there any use for a 1405 other than for parts?
Has any one converted on to a general purpose tracking
generator?
Thanks
Glenn
--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI, FRA, NRA-LM ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
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Re: water splashed on face of scope (TDS754C)
Morning (UK time)
At Tek in the UK, at the old Harpenden site in the late 70's, we used to jet-wash 'scopes (the older 500 series, and some 400 series.? With an industrial detergent/water mix, then rinse with the same washer filled with plain clean water.
The tool was more like a large bore paint sprayer, compressed air would draw the fluid from the cup, and expel it as high speed liquid and foam, or just aerated water.? A choice of sash brushes were used on the front panel to remove suborn dirt.
You'd be amazed at the amount of dirt and other crud that would come out!? Some of the kit was believed to be used underground, from the name of the customer.
Then, they were left in a drying oven heated to something like 40'C with passive ventilation for a week at least.
The 500 series usually needed the fan motor bearings (and some rotary switches) re-lubing, plus the filter mesh replacing if it fell to pieces during it's prior removal and wash (no bad thing.) The 400's just left to dry, and maybe a few switches dosed with a small amount of IPA or similar solvent, NOT "Switch Cleaner".? I don't recall any issue with damaging any pot's or transformers, and certainly to my knowledge, no CRT's were damaged.
Most of the older 'scopes would then power up (if not actually "Faulty") and many even worked to specification after warmup.
In those days, we'd do a full performance check* and re-calibration "Adjustment" to get best performance anyway, none of this modern faff just check if it's "in spec'", rubber stamp a document stick another sticker over the old ones and out the door with it, that happens these days.
(* Recording the results before and after cal', if the customer wanted, for extra ? or $.)
Electronics is remarkably tolerant to water, so long as it is not powered up at the time, and any dirt/residue that accumulates in low spots doesn't affect anything HV or RF related.? But, it has to be thoroughly dried out of course before power is re-applied later..
Regards to All.
Dave B.? Ex Tektronix UK.? (Harpenden, later Maidenhead.)
--
Created on and sent from a Unix like PC running and using free and open source software:
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Re: water splashed on face of scope (TDS754C)
I routinely run boards through the dishwasher, including many boards from these TDS scopes and have yet to kill one.
Latest run was an old Asus motherboard (with ISA slots for NI GPIB cards to get a TDS cal PC up and running)
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If it was clean water and there was no power applied, it'll be fine once it's dry.
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I would open the case, remove the front bezel and control panel and dry with a clean rag and also a gentle blast of compressed air if available.
Then let it sit for a couple days in the shaded sun and breeze to dry out.
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It'll be a good chance ro blow all the dust out, give the front of the CRT a good clean and replace the Rifa and low ESR capacitors on the PSU board that always fail. :)
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Jared.
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Burt K6OQK
Eric Boyle
Richard
Froggie the Gremlin
Jared Cabot