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Re: 576 shaft repair
The advantage of my heat shrink solution is it is non-conductive. The two ends of the shaft don't meet inside the heat shrink because the original broken flexible coupler prevented them from doing that in the first place. In addition Tek used plastic shafts for this kind of thing so those were non-conductive to begin with and they get inserted into the ends of the heat shrink tubing and held in place with the bead of epoxy.
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Hobby shops sell lengths of plastic rod that have enough flexibility that they can sometimes do away with the flexible coupler in the first place. They are easy to cut to length. I find all sorts of interesting materials in hobby shops that can be repurposed to repair parts of Tek equipment. They are a fascinating place to browse around in these days. Parts are generally inexpensive as well. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
Re: 576 shaft repair
Helge Kyndbo
tor. 18. apr. 2019 kl. 10.43 skrev David C. Partridge <
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david.partridge@...>: IIRC some flexible couplers in the 576 have the be insulating up to the |
Re: 576 shaft repair
IIRC some flexible couplers in the 576 have the be insulating up to the full voltage output of the 576.
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I know that because I needed to replace one and luckily Hakan Hintze had one on stock. David -----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Dennis Tillman W7PF Sent: 18 April 2019 03:41 To: [email protected] Subject: Re: [TekScopes] 576 shaft repair Hi Neil, I had a slightly different problem but I think this might work for you. But first, companies like McMaster-Carr () sell flexible couplers that can be substituted for the broken ones you have. If they don't have one that will work for you try what I did next: What I have done in the past is taken a piece of heat shrink tubing that is a close fit before shrinking. It should be long enough so about a half inch of heat shrink is on the shaft on each side of where the coupler used to be. I put a dab of epoxy all the way around each end of heat shrink and then insert the heat shrink onto the two shafts. With a heat gun I shrink the tubing. When the epoxy dries it is glued to each end of the shaft. The small section of heat shrink tubing in the middle where the coupler used to be should be nice and flexible and act like the coupler did. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
Re: 576 shaft repair
Hi Neil,
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I had a slightly different problem but I think this might work for you. But first, companies like McMaster-Carr () sell flexible couplers that can be substituted for the broken ones you have. If they don't have one that will work for you try what I did next: What I have done in the past is taken a piece of heat shrink tubing that is a close fit before shrinking. It should be long enough so about a half inch of heat shrink is on the shaft on each side of where the coupler used to be. I put a dab of epoxy all the way around each end of heat shrink and then insert the heat shrink onto the two shafts. With a heat gun I shrink the tubing. When the epoxy dries it is glued to each end of the shaft. The small section of heat shrink tubing in the middle where the coupler used to be should be nice and flexible and act like the coupler did. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
Re: 576 shaft repair
Dan Cordova
I can 3D print a part from ABS plastic.
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However, I will need either a CAD file or the part itself to measure dimensions and then create a .stl file.? Lately, I've been using Fusion 360. ?You can get a free download. ?A 3 year license is available to students and educators. ?I can also use SolidWorks. ? Thanks, Dan On Wednesday, April 17, 2019, 6:18:28 PM PDT, groups@... <groups@...> wrote:
Apologies if this has come up before! I have a 576, and the plastic couplers for the Intensity and Focus knobs are, of course, broken. They look fairly hard to find, so I'm wondering what the best option is - has anyone 3D printed replacements, for example? There's also a video where a 577 has a similar repair accomplished with plastic tubing (). One other thing - I've seen CRC 5-56 mentioned as the recommendation for cleaning switches, but it no longer seems to be available - instead replaced by CRC 05005. Is that an acceptable substitute, or should I use something else? Thanks, Neil |
Re: Absurdly simple way to get contact cleaner into some Tek pots
Hi Dave,
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Most pots are not waterproof but they are "sealed". They are intentionally designed to be assembled in such a way that they keep atmospheric borne contaminants out. At the same time they are quite configurable in myriad different ways. Some time ago I came up with my own variation on an article I first read in TekScopes, about how each of the field offices sprayed each scope that came in for calibration and repair with deionized water and then baked it overnight. What I was doing was totally immersing problematic plugins in Isopropyl alcohol. I left them in it for s while to allow the alcohol to soak into everything and loosen up dust and debris. While immersed I would brush the components on the circuit board to free up any dirt and particles that had attached themselves to the board. I would also routinely turn all the pots, dials, and knobs, and push all the switches. I only stopped because it was a hassle filtering the dirt and debris out of the Isopropyl after words (I used filter paper when I should have used a Buchner Funnel). Eventually the Isopropyl accumulates dissolved contaminants which I removed with a laboratory hot plate and a distillation apparatus). That works real well but it is also a hassle. Cleaning plugins this way worked extremely well. I only ever had a problem once when I discovered the numbers inside the 7T11 Sweep Range knob floating in the Isopropyl. To this day I have no idea why they came off. From that point forward I removed that knob from all 7T11s before bathing them. The point of bring up my way of cleaning plugins was to let you know the isopropyl did get into all of the Tek pots. I know this because there were no noisy pots on my plugins after they got Isopropyl baths. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
Re: Tek 1480C waveform monitor vs oscope
On Wed, 17 Apr 2019 17:12:06 -0700, you wrote:
At the time I was doing that, it would have been wonderful. I had some home-built equipment that I used. I may have been the first to transmit color on the Baltimore Maryland ATV repeater. That being said, I do agree with your assessment, that and perhaps the corresponding color burst monitor would be quite good. Ditto with a test generator that if needed, could supply signals to everything (tek 1910, for example). If you never do video, however..... Harvey
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Re: Absurdly simple way to get contact cleaner into some Tek pots
Hi Gary,
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The contact cleaner I was using is MG Chemical's "Super Contact Cleaner with poly phenyl ether". It is in a pressurized can and it comes with a 6" long tube nozzle which goes all the way into the screw hole of the pot. The briefest squirt deposits contact cleaner in the main chamber of the pot. If it is a ganged pot the blowback from the squirt will deposit contact cleaner in the ganged pot as well. Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
Re: More Complete List of Concept Series and Measurements Concepts Books
What site are you and Roy referring to? Please include context (we aren't mind readers) so we don't have to guess.
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Dennis Tillman W7PF -----Original Message----- -- Dennis Tillman W7PF TekScopes Moderator |
Re: FOLLOWUP RE: [TekScopes] If you own a 7854 READ THIS
Very late to the party (as usual...) I just had a thought I wanted to throw out there.
My best understanding of the data sheet is that the 555 contact form is really just the 500 contacts with two bends in them in the right place. The difference between the -201 and -202 mounting options appears to be that the 202 has mounting lugs with holes in them, and 201 has no lugs. In other words, for someone who enjoyed this kind of mechanical work... making a little jig to put the bends in the right places in the pins, and cutting off the mounting lugs neat and tidy, probably wouldn't be terribly difficult to do. On the other hand, for someone who doesn't do that kind of thing or doesn't like it or otherwise objects... maybe not! The 346-080-500-202 parts are non-stocked, but apparently can be obtained with a certain amount of patience and effort; I think DigiKey wanted a 25 piece minimum order, Mouser seems okay with an order of 1. |
576 shaft repair
Apologies if this has come up before! I have a 576, and the plastic couplers for the Intensity and Focus knobs are, of course, broken. They look fairly hard to find, so I'm wondering what the best option is - has anyone 3D printed replacements, for example? There's also a video where a 577 has a similar repair accomplished with plastic tubing ().
One other thing - I've seen CRC 5-56 mentioned as the recommendation for cleaning switches, but it no longer seems to be available - instead replaced by CRC 05005. Is that an acceptable substitute, or should I use something else? Thanks, Neil |
Re: Tek 1480C waveform monitor vs oscope
It might also be of use to the small sub-group of radio amateurs that do TV.
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John On 4/17/2019 7:55 AM, Harvey White wrote:
On Wed, 17 Apr 2019 07:06:19 -0700, you wrote:I have been given this tool. I have a Tek 2246A and a Hitachi scope already. What can I do with this that I can't with the other scopes? I have never done anything with video nor intend to. Also, the trace is hiding deep lower left of CRT. Can't get it out of there.If you're doing anything with baseband video, such as CCTV cameras for |
Re: 475A : excessive jitter on delayed sweep
99.44 % sure the mark on a Ta cap is the positive terminal.? If it is in backwards it will say so loudly.
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Regards On 4/17/2019 7:23 AM, Alberto I2PHD wrote:
On 2019-04-16 16:35, Alberto I2PHD wrote:There is a suspect tantalum capacitor, which I did not replace, namelyProblem fixed. I replaced that suspect capacitor with a 4.7uF, 100V electrolytic, and now the delay time after which the B sweep starts is rock stable... |
Re: Absurdly simple way to get contact cleaner into some Tek pots
I have never seen any noticeable lingering effects from electronic cleaning
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solvents on the resistive elements. Most electronic cleaning agents evaporate and leave no residue. Even the solvents that leave a slight oily surface seem to have no effect on the value of the resistor element. Gary On Wed, Apr 17, 2019 at 9:43 AM tom jobe <tomjobe@...> wrote:
This has been a very interesting thread on how to clean potentiometers, --
Gary Robert Bosworth grbosworth@... Tel: 310-317-2247 |
Re: Absurdly simple way to get contact cleaner into some Tek pots
ironcoder@... wrote on 4/17/2019 1:26 PM:
Yes Gary, I ruined a pot years ago from carelessness. I am very very cautious now. You want to drill the outer cover but not let the drill enter into the pot itself at all.Hello-- Another pot-related problem arises in older equipment (e.g., antique radios) when a tin-plated outer steel shell sprouts tin whiskers: Dislodged whiskers inside the pot can cause crackling intermittents. 73-- Brad? AA1IP |
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