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Re: Recreating an old board for the 7854
Well, actress Barbara Feldon is still alive? evidently.? ?She's 88, though, so not nearly as hot as she was in Get Smart.? ? ? ?Jim?Sent from my Verizon, Samsung Galaxy smartphone
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-------- Original message --------From: Clark Foley <clarkfoley@...> Date: 7/20/21 12:49 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] Recreating an old board for the 7854 Where is Agent 99 when you need her!
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Re: Recreating an old board for the 7854
You guys aren't as Smart as you think you are!? ? ? ? ? ? Jim Ford?Sent from my Verizon, Samsung Galaxy smartphone
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-------- Original message --------From: Tom Lee <tomlee@...> Date: 7/20/21 12:17 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] Recreating an old board for the 7854 Missed it by that much.Sent from my iThing, so please forgive typos and brevity.> On Jul 20, 2021, at 12:13 PM, Clark Foley <clarkfoley@...> wrote:> > ?Would you believe octal latches? Sorry about that, Chief.> > > > >
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Re: Recreating an old board for the 7854
Thanks for all the help.
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I have about 80% finished with the schematic. I need to find a replacement for the 2N5769 The documentation says this was a "Switching Transistor" but it does not say the switching frequency. But that is the next hurdle that needs to be cleared. I will post the schematic and the board layout when it is finished to make sure I did not make any errors. Also need to get the pin outs for P190. At the moment P190 looks like it is the board edge connector. All advise is welcome and thanks in advance. -----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Raymond Domp Frank Sent: Tuesday, July 20, 2021 3:28 PM To: [email protected] Subject: Re: [TekScopes] Recreating an old board for the 7854 On Tue, Jul 20, 2021 at 09:12 PM, Clark Foley wrote: Since we're at it: It's not 8 latches: There are 8 D-type flip-flops in a '374. Latches pass the input with one control level (the output follows the input, no clock involved) and latch their input value with the control at the other level, much like an analog sample and hold. Compare 7475 (quad latch). The '374 uses a clock to transfer the data at the D-inputs to the complementary outputs. Raymond |
Re: Recreating an old board for the 7854
On Tue, Jul 20, 2021 at 09:12 PM, Clark Foley wrote:
Since we're at it: It's not 8 latches: There are 8 D-type flip-flops in a '374. Latches pass the input with one control level (the output follows the input, no clock involved) and latch their input value with the control at the other level, much like an analog sample and hold. Compare 7475 (quad latch). The '374 uses a clock to transfer the data at the D-inputs to the complementary outputs. Raymond |
Re: Replace/Repair TM 500 Module Side Panel Latch
I have purchased TM500 plugins from reputable sellers (eg. Stewarts of Reading, Telford Electronics) and from less well-known purveyors on eBay and have found several broken latches of this type. The common "fix" seems to be to use a bit of some kind or insulated wire to wrap around the engaging parts. Since the casual observer will have no idea of this "fix" when the plug-in is in a power mainframe and in use, I can't see any problem with it. Of course, if someone were to manufacture facsimiles of the original latches and sell them at pocket-money prices, then I would be interested, but not at something like $50 each - that may be justifiable, but it is not economic, in my opinion. Others with deeper pockets may (and are welcome to) disagree.
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Colin. -----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Jeff Dutky Sent: 20 July 2021 19:36 To: [email protected] Subject: Re: [TekScopes] Replace/Repair TM 500 Module Side Panel Latch Cory, I have no experience replacing the latch, but I have a side cover that looks exactly like yours, where the latch seems to have broken internally: the slotted side rotates, but the latch side does not. I also have a TM500 "toolbox" with a solid cover and a similar latch mechanism. The latch seems to be made of two parts, the latch side and the slotted side, which snap together on a central shaft. I would expect that you could push the center shaft out of the latch side with a small screwdriver or punch, but I haven't tried this. If your latch is broken like mine, however, you don't have much to lose by experimentation (nor do I, so I will see what I can achieve). One solution would be to simply glue to the two halves of the latch together, maybe by dripping some epoxy down the hole on the latch side. This would be a fairly permanent fix (you would not be able to take the latch apart again without some amount of destruction) but I imagine a permanent fix is kind of what you are looking for. -- Jeff Dutky |
Re: Looking for data on 9-pin Vacuum time delay relays used in old Tek-scopes
These can still be found as NOS on eBay. I bought a 6NO45T, a couple months back for around $10, for a Tek 551 I'm restoring. Turned out I didn't really need it. The main open-air PS relay that the timer triggers was sticky and had dirty contacts.
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Re: Recreating an old board for the 7854
Missed it by that much.
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Sent from my iThing, so please forgive typos and brevity. On Jul 20, 2021, at 12:13 PM, Clark Foley <clarkfoley@...> wrote: |
Re: Replace/Repair TM 500 Module Side Panel Latch
Cory,
I have no experience replacing the latch, but I have a side cover that looks exactly like yours, where the latch seems to have broken internally: the slotted side rotates, but the latch side does not. I also have a TM500 "toolbox" with a solid cover and a similar latch mechanism. The latch seems to be made of two parts, the latch side and the slotted side, which snap together on a central shaft. I would expect that you could push the center shaft out of the latch side with a small screwdriver or punch, but I haven't tried this. If your latch is broken like mine, however, you don't have much to lose by experimentation (nor do I, so I will see what I can achieve). One solution would be to simply glue to the two halves of the latch together, maybe by dripping some epoxy down the hole on the latch side. This would be a fairly permanent fix (you would not be able to take the latch apart again without some amount of destruction) but I imagine a permanent fix is kind of what you are looking for. -- Jeff Dutky |
Re: AA 501A Parts, DM 501A Probes
Likely no surprise to most if not all, Sphere in Canada has the AA 501A parts I need, with some caveats: the knob is a dark grey type rather than light grey as originally fitted (no big deal there), and the side panel is missing the 1/4 turn latches. I have a separate thread I started about tips for removing or repairing those, or if there are possibly replacements available.
Anyway, just wanted to follow up. Thanks again for all the helpful info! Cory Oace |
Re: Recreating an old board for the 7854
There is an early prototype of that fixture. It allows the analog scope to function without any other digital cards. The prototype is a subset of 067-0912-00. It is pictured on Kurt R¡¯s tekwiki page for the 067-0912-00 fixture. It allows selecting Vert and Horiz display modes. It reduces the 7854 to a 7804N. Contact Dennis Tillman. I gave him a board a couple of years ago. He made an offer to this group to have a few made but nobody was interested at that time.
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Re: Replace/Repair TM 500 Module Side Panel Latch
On Tue, Jul 20, 2021 at 07:01 PM, sweetbeats wrote:
/g/TekScopes/album?id=266281 Raymond |
Replace/Repair TM 500 Module Side Panel Latch
Greetings!
Does anybody have any experience removing or repairing the 1/4 turn latches found on the side panels of some TM 500 modules, or are there replacements available? I added a new album titled TM 500 Side Panel Latch with a picture of the part I¡¯m talking about¡not sure how to link that here¡apologies. Cory Oace |
Re: FIXED! Shock Mount Replacement for Type D and Type H 500-series plugins (was [TekScopes] Another interesting Tektronix web site)
UPDATE
Looks like you get the same hollow-ball shock mounts in any of the following DJI RC copter ¡°Zenmuse¡± camera mount parts kits: Part 42 for H3-3D; Part 3 for H4-3D; and Part 7 for Z15. They are for sale (multiple sellers) at ebay and Amazon. These contain four to eight of the part you want and are cheaper than direct-sourcing the Barry Controls 275-1N, which is around $10 each. Dave Wise From: [email protected] [mailto:[email protected]] On Behalf Of Dave Wise via groups.io Sent: Thursday, July 15, 2021 4:29 PM To: [email protected] Subject: FIXED! Shock Mount Replacement for Type D and Type H 500-series plugins (was [TekScopes] Another interesting Tektronix web site) FIXED! "DJI ZH3-3D Damping Rubber Set (Part 42)", less than $10 at ebay. This is four bags of four different isolators, for an RC helicopter camera mount, one of DJI¡¯s ¡°Zenmuse¡± series. The ridged ones are too soft. The ball shaped ones (two bags, gray marked "A40" and white "30") are, as far as I can tell, *perfect* drop-in replacements. From my repair notes: These are 348-0007-00. 348-0087-00 plus 361-0113-00 (used in 1A6 and 1A7) might work too. One of the three replaced way back when is now severely crazed. Bad batch of rubber? I tried Julian Bunn's fan mount rejuvenation procedure (see "Another interesting Tektronix web site" at Tekscopes at groups.io). Soak in olive oil 1/2 hour, boil in water 5 minutes. No effect, must be a different rubber. Original part 348-0007-00 is a hollow rubber ball approx 15mm dia across equator, with a 12mm OD flange at each end. Rubber is about 1.5mm thick. Neck OD 9mm, neck to neck 11mm. Clearance hole for #8 screw. Chassis holes are 5/16" (8mm). Dave Wise From: David Wise Sent: Monday, June 21, 2021 5:12 PM To: [email protected] Subject: RE: [TekScopes] Another interesting Tektronix web site Maybe 275-1N or 7110-0.5 or 7110-1.0 . The latter can be had for $8 each at <> . Dave Wise From: [email protected] [mailto:[email protected]] On Behalf Of stevenhorii via groups.io Sent: Monday, June 21, 2021 3:52 PM To: [email protected] Subject: Re: [TekScopes] Another interesting Tektronix web site All on this thread, There are Barry mounts which come in various sizes and damping abilities: <> Scroll down the pages of this distributor¡¯s Web site until you get to ¡°Ball mount series¡± which sounds like what you are looking for. I have no conflict of interest with this company. I have seen Barry mounts used quite a bit in various pieces of equipment when isolation from vibration is important. Steve Horii On Mon, Jun 21, 2021 at 14:34 Dave Wise <david_wise@...> wrote: Thank you, Daniel, for your research and ideas. |
Re: Working on the HV Section of a 533A
I use a TC-201 with 700F screwdriver tip. You want mass more than temperature. Silver-bearing solder. In and out quick. Careful not to wedge the tip in the slot, it will break it.
FWIW, Dave Wise From: [email protected] [mailto:[email protected]] On Behalf Of ¸é±ð²Ô¨¦±ð via groups.io Sent: Tuesday, July 20, 2021 8:22 AM To: [email protected] Subject: Re: [TekScopes] Working on the HV Section of a 533A Jeff- working on older parts the oxide on the leads impedes "solder-ability", so just a gentle cleaning. scotch-brite(red/green/grey), I use whatever is nearby (green/grey at the bench). Re the tips they do go bad with time/use I would run with the screwdriver, the long conical generally does not have the mass to do fast transfer of heat. it is not so much the temp ( to a point) as is the quick heat/in&out, try the 800 it may work but beware of burning the rosin. too much heat is just as bad as not enough. Those high temps were not allowed ( and for good reason) to be found in the rework area or at our engineering benches the govt oversight would have a fit, I caused enough grief with procedures that got things done and fixed properly before my ECN could be approved. I hid most of my unapproved tools 99% of the time. I like the Weller gun for tip interchangeability and one could shape the tip as needed. they are not ESD safe! as you know every tool has its applications and limitations. ( they are inexpensive now days ~$5 used at garage sales etc...best one has nuts to hold the tips but beware of stripped threads...they kept making modifications to the attachment point until it worked poorly ) ¸é±ð²Ô¨¦±ð On 7/20/21 12:15 AM, Jeff Dutky wrote: ¸é±ð²Ô¨¦±ð, |
Re: Working on the HV Section of a 533A
Jeff-
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working on older parts the oxide on the leads impedes "solder-ability", so just a gentle cleaning. scotch-brite(red/green/grey), I use whatever is nearby (green/grey at the bench). Re the tips they do go bad with time/use I would run with the screwdriver, the long conical generally does not have the mass to do fast transfer of heat. it is not so much the temp ( to a point) as is the quick heat/in&out, try the 800 it may work but beware of burning the rosin. too much heat is just as bad as not enough. Those high temps were not allowed ( and for good reason) to be found in the rework area or at our engineering benches the govt oversight would have a fit, I caused enough grief with procedures that got things done and fixed properly before my ECN could be approved. I hid most of my unapproved tools 99% of the time. I like the Weller gun for tip interchangeability and one could shape the tip as needed. they are not ESD safe! as you know every tool has its applications and limitations. ( they are inexpensive now days ~$5 used at garage sales etc...best one has nuts to hold the tips but beware of stripped threads...they kept making modifications to the attachment point until it worked poorly ) ¸é±ð²Ô¨¦±ð On 7/20/21 12:15 AM, Jeff Dutky wrote:
¸é±ð²Ô¨¦±ð, |
Re: Working on the HV Section of a 533A
531/535/541/545 are the first generation of 500-series scope. 533 is second-gen, 533A is third. Black Beauty and Good-All from this era use plastic film insulation just like modern caps. In general they are no more likely to be bad than a modern cap.
That said, some also contain a layer of paper (Sprague trademark ¡°DiFilm¡±), which by now has caused the cap¡¯s Dissipation Factor to increase. In most applications, it doesn¡¯t matter. The 1nF cap that resonates the transformer primary is sensitive to DF however, and a lossy one can prevent oscillation. Something to watch for but not in the ¡°front row¡± of suspects. If you have a bad cap in the HV section, it¡¯s most likely to be one of the 10kV-20kV ¡°doorknobs¡±. Now and then they short-circuit. The ceramic disks Tek used are very high quality, better in some ways than modern caps unless you really shell out the dollars. My 500-series mainframes are still using their original electrolytic caps. If it was my scope, I¡¯d just power the thing up. If you test the electrolytics in-circuit, remove all the tubes first. (Note where each one goes, some are aged/screened/matched.) Otherwise you will ruin some by puncturing the heater-cathode insulation. That¡¯s why Tek uses a time-delay relay. It¡¯s good you¡¯re cleaning the ceramic strips; there are a couple of ¡°sore spots¡± where high potential between adjacent terminals causes silver migration which will eventually arc over and (at the least) ruin the strip. The SNAP! made me jump a foot. Rather than replace the strip (lower left corner of the B sweep chassis, that¡¯s not present in your model), I started an experiment by grinding off the flashed-on silver and painting the spot with corona dope. Not to suppress corona but to forestall further migration. I don¡¯t know if it helps, ask in ten years. Be sure you¡¯re not leaving any conductive residue behind, it will just hurry the strip to its doom sooner. HTH, Dave Wise 535, 535A, 545, 547 From: [email protected] [mailto:[email protected]] On Behalf Of Mark Vincent via groups.io Sent: Monday, July 19, 2021 7:32 PM To: [email protected] Subject: Re: [TekScopes] Working on the HV Section of a 533A Jeff, Brenda is right about the corona dope. Leave those strips in. Clean them to remove dust. I have not seen any of the black beauties any good. These are a wax condenser in a plastic case. I replace them on sight. The Good-all ones I also replace on sight. Replacements I use are Sprague Orange Drops or other high quality ones at 630V, e.g. Panasonic. Radial types work fine to replace axial. Mark |
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