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Re: DC508 HELP with PHOTOS option 7
Hi Miguel,
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Thank you for the Interconnect book. I also looked at page 19-5 TR502 Tracking Generator. This appeared to be duplicate information for what is on page 17-3. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
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Re: Opinions on the 465B
I paid $150 for one about five years ago on Ebay
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Clyde On Tue, Mar 12, 2019, 19:56 KA6UUP <ka6uup@...> wrote:
I have a chance to buy a 465B which seems to work fine |
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2246 no display/odd behavior
Most esteemed,
My 2246 presents with the following symptoms: At power on the fan runs but nothing on the display is visible and none of the front panel button lights illuminate. I can get the front panel to come to life by repeatedly pressing random buttons. Otherwise, it will not come to life on its own no matter how long I let it sit. The screen remains blank, however, no matter what I press. My suspicion is the SMPS. I measured ripple on all the rails. See here: Note that I change the time scale on a few measurements. Assuming I've measured these correctly, does the SMPS seem to be a likely culprit? Or if not, other suggestions on where to diagnose? |
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Re: 2467B geometry
Chuck Harris
Power supply coupling between the amplifiers would most
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certainly have a dynamic component to it. This is purely static in nature. I can move the dot using the H and V position controls, and retrace any line on the screen. I think if the 2467 had all of the adjustments of the 7104 CRT, I would be able to adjust out the problems... Unfortunately, the 2467 connections to the various anodes used in the 7104 are entirely internally connected, bringing out only a single wire (Geometry) to bias 4 or 5 internally connected anodes. -Chuck Harris Ed Breya via Groups.Io wrote: One more thing - what if there's X-Y interaction in the deflection amplifiers, due to coupling via the power supplies? Ed |
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Re: 2467B geometry
Chuck Harris
The 7104 CRT is really nothing like the 2467 CRT.
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The 7104 is like a test bench for CRT adjustments. It has: Horizontal Bowing (Slot) Vertical Linearity (Egg) Geometry (Bowtie) Horizontal Sensitivity (Sides) Shield AVE Plate E Ave Plate E Stigmator Astigmatism Focus And, the MCP input and output. The 2467 has Geometry, Anode1, Astigmatism, Focus, a box lens, and the MCP. The 7104 CRT is about a foot longer than the 2467, so it doesn't need the box lens. I guess when a CRT costs $30K, you try harder... -Chuck Harris Ed Breya via Groups.Io wrote: I'd recommend looking at some 7104s, and comparing them to the 2467s. Don't they both use the same CRT type? If the 7104 appears much better with respect to geometry, then it may be worth looking into the details to see if the associated circuits and adjustments differ. Or, maybe the CRT mounting method and environment can explain some differences in the magnetic fields around the CRT. |
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Re: 577 Curve tracer ringing CRT and noisy step generator
For U380 (installed NEC C1458C) U350 (installed 156-0158 RCA) U305 ((installed 156-0158 RCA) I will be replacing with MC1458P from digikey
As for U360 (installed 1560067-02) this proves to be a more difficult to find IC however I did find VA741TC from the website listed above, if anyone has any advice please let me know. |
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Re: 577 Curve tracer ringing CRT and noisy step generator
The bad IC sockets are due to corrosion plus a design flaw. The sockets in
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question were made by TI and are used very heavily in Tek gear. They contact the IC pins on the narrow edges instead of the broad edges and thus contact area is significantly reduced and more susceptible to corrosion. If you have these sockets and they are showing signs of corrosion/high contact resistance, it is advised to replace them. Dave Casey On Tue, Mar 12, 2019 at 8:55 PM <wilson2115@...> wrote:
/g/TekScopes/photo/86536/3?p=Name,,,20,1,0,0 |
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Re: 577 Curve tracer ringing CRT and noisy step generator
/g/TekScopes/photo/86536/3?p=Name,,,20,1,0,0
I included a diagram of the step generator, check the link above for review I found these socketed IC's on the step generator board U570 Microcircuit Li Low input offset current U530 Microcircuit Li Low input offset current U520 Microcircuit Li Low input offset current U380 Microcircuit Li Operational amplifier U350 Microcircuit Li Dual operational amplifier U360 Microcircuit Li Operational amplifier U430 Microcircuit Di Quad 2-input Pos Excl Gate U268 Microcircuit DI 2 input and or invert gate U270 Microcircuit Di Monostable Mv TTL I am considering replacing the op-amps and keeping the old ones around. When you say bad IC sockets do you mean loose, broken, or corroded pins? Thanks |
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Re: Tek Blue Paint at Stuff Day
What a shame there is no "Stuff Day" in the UK :-(
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On 13/03/2019 00:06, walter shawlee wrote:
Just a note that I will have a few new cans of Tek blue spray paint (the exact stuff) |
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Tek Blue Paint at Stuff Day
walter shawlee
Just a note that I will have a few new cans of Tek blue spray paint (the exact stuff)
at our upcoming Stuff Day event at Sphere (april 13th). Maybe somebody can drive a few cans back for others? it can't be shipped by air, so only ground transport is possible. what anightmare it was to buy orignally. Lots of great Tek 300 series portables will also be at Stuff Day, and you can browse the Tek and hp knob drawers for that weird knob you really need. way too many to photograph and list on line, and of course, the knobs have no numbers on them... there's also tons of original printed manuals by the pound. stuff day: all the best, walter walter2 -at- sphere.bc.ca sphere research corp. |
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Re: Tek Blue Paint - the story goes on ... :-)
Dave I have stripped a lot of Tektronix scopes. First, never use oven cleaner. I have used it on motorcycle parts and it is highly corrosive to aluminum. Second, aircraft stripper is not necessary either. I always have used the lightweight paint stripper from the hardware store which has worked just fine. If you want to see pictures of just some of my repaints take a look at my google photos.
John. |
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Re: 2467B geometry
I'd recommend looking at some 7104s, and comparing them to the 2467s. Don't they both use the same CRT type? If the 7104 appears much better with respect to geometry, then it may be worth looking into the details to see if the associated circuits and adjustments differ. Or, maybe the CRT mounting method and environment can explain some differences in the magnetic fields around the CRT.
Ed |
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Re: 577 Curve tracer ringing CRT and noisy step generator
Having repaired several of these, apart from PSU problems (low value caps, o/c diodes etc), most problems are with the really bad IC sockets, which in worst case you will need to replace. Other than that the op-amps can be just weird, many faults can be cured by replacements. I had one that had uncurable glitches on the trace and added 0.1uF caps across the power rails right on some of the logic chip power pins, can't remember which, sorry. One had a collector transformer breaking down, eventually burned out, not fun. That was fine until collector volts turned up...........then arcing.
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Re: 2467B geometry
Chuck Harris
Hi Jon,
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There is no optical zoom on this camera/phone. The electronic zoom just reduces the pixel count without changing the "size" of the finished picture as described in the meta data. If I thought is was majorly important I would have brought out my Nikon D3... it isn't. Everything you need to know can be seen by observing how the trace weaves in and out of the graticule lines. There is no Geometry setting that will make the center line better. It is bowed even more upwards with the Geometry control in more clockwise positions. It could be a bad CRT. It doesn't look like the scope has been hit hard on any surface. I didn't have to straighten the metal case at all... no dents, no scratches. There is a slight ding on the left side of the CRT bezel, above the intensity control. But, I have no idea of the history of this scope. It clearly has undergone several repairs, or attempts at repairs. New attenuators, new U800, new Zaxis hybrid, and new trigger hybrid, as I recall. For all I know, the reason the scope shows no signs of being dropped, is because the previous owner replaced all of the broken parts (attenuator, CRT, case, bezel...). -Chuck Harris Jean-Paul wrote: Chuck: UGH! I understand your frustration. This is the best setting of GEOM = full CCW? The 4 I have are either 100% or just slightly off grid. Only the 2467B is noticable. |
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Re: Looking for Sony-Tektronix 318 Logic Analyser Operator's Guide
To all who responded on this topic:
H?kan Hintze (he proves to be an open treasure pit again!) sent me a scan of the 318|338 operator's manual. I will upload it to TekWiki (another invaluable resource) tonight or tomorrow so it will be available for all. Thanks to all who responded! Raymond |
John Williams
Raymond Domp Frank