Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- TekScopes
- Messages
Search
|
Re: - Early Telequipment 'Scope
Hi Ken,
toggle quoted message
Show quoted text
I would be interested if nobody nearer to you pops up - bit of a drive from Eastern Anglia. Does it have its case by any chance? Mine does not and I'm trying to re-create one based on a very tiny, badly scanned image from a copy of a 1957 Wireless World, and struggling! All I can deduce at the moment is that it may have been constructed more like the single '5-sided box' design of the later S51 than the three piece 'clam shell' design of the face-lifted S31 because it is missing all the fixing holes it would need to hold the base part of that on. I would really appreciate a pic! All the best, Adrian On 6/21/2018 1:35 PM, Ken wrote:
Hi Adrian and group, |
|
Re: Tek 465 no display
Albert and LolPol,
Thank you for your input. Somehow i missed this download. I found LV test points and values in section 6 of this manual. I'll report my findings this weekend when i have some time to get back to testing....maybe sooner. The monsoon season here has started and my 4 hectares eats up allot of my free time in the lab, but green is beautiful compared to dry brown winters at our 1200 m elevation. I also found allot of info in the charts and schematics in the last part of the 465 late .pdf. The display troubleshooting will be of help hopefully once i verify my LV test points. I dont have a HV probe for my VOM and don't have the source here for the appropriate resistors to build an appropriate voltage divider, so I'm hoping the solution is something in the LV circuit. Is there a source for pdf or other format files of the foldout pages in unchopped original layout? It would make reading them much easier. I guess that I could print/splice/tape the ones i need.... Thanks again! I feel the cloud lifting! Russ |
|
Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
On Thu, Jun 21, 2018 at 09:37 am, machineguy59 wrote:
OUCH!! Yahoo email to groups.io lost context. So here is the message again. Menahem, Thanks for the information. I was not clear in expressing my concern. I will clarify my problem. The A5 boards I have suffered severe electrolyte damage. One of them (my current project) lost three pads and two traces to the etching of spilled electrolyte. I replace these pads with pads cut from foil and glued to the board with CW2500 epoxy. You can see an example of this process here: Although my hand cut pads are not as perfect as his machine cut pads. I get pretty close. Also, my hand cut traces are not as narrow as original. I will try to post pictures of my work next time I have the scope opened up. I did not take "before" pictures. Its tedious but it works and saves the board without using jumper wires or gluing parts to the board. My concern is that CW2500 epoxy is great stuff but still not as good as original for strength. The weight of a leaded part leveraged by the leads would very likely wrench my replacement pads from the board. |
|
Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Menahem,Thanks for the information.? I was not clear in expressing my concern.? I will clarify my problem.? The A5 boards I have suffered severe electrolyte damage.? One of them (my current project) lost three pads and two traces to the etching of spilled electrolyte.? I replace these pads with pads cut from foil and glued to the board with CW2500 epoxy.? You can see an example of this process here:??PCB solder pad repair & corrosion clean up - The epoxy method ?
toggle quoted message
Show quoted text
| | | | | | | | | | | PCB solder pad repair & corrosion clean up - The epoxy method This is a demonstration of a PCB repair which involves repairing damaged surface mount solder pads as well as cl... | | | Although my hand cut pads are not as perfect as his machine cut pads.? I get pretty close.? Also, my hand cut traces are not as narrow as original.? I did not take "before" pictures.? Its tedious but it works and saves the board without using jumper wires or gluing parts to the board.? My concern is that CW2500 epoxy is great stuff but still not as good as original for strength.? The weight of a leaded part leveraged by the leads would very likely wrench my replacement pads from the board.? I will try to post pictures of my work next time I have the scope opened up. On ?Thursday?, ?June? ?21?, ?2018? ?05?:?15?:?13? ?AM? ?CDT, M Yachad <yachadm@...> wrote:
Ron "I don't think the repair pads will do well with a leaded cap hanging on it." I have done many PCB repairs, replacing the SMD components with Leaded. See here: /g/TekScopes/album?id=60615 This is of a Bose Music system - CD-Control PCB - before and after. There is very little vertical clearance, so they lay horizontal. The SMD pads are more than large enough to accommodate the soldered leads, and as long as the soldering is kept to the same standards as for SMD caps (less than 2 secs, at 270¡ãC), there is no danger of lifting the pads. This is my standard way of working with SMD PCB's now; same process on all the TV T-Con PCB's which I work on (TV PSU PCB's are still Through-Hole). I find it super-reliable, even if it won't win any aesthetics awards, and have not experienced any comebacks at all, on any of the hundreds of SMD PCB's which I have overhauled in this way. |
|
Speaking of capacitor problems - it's not always their fault
With all this capacitor talk, I thought I'd relate a recent experience in patching up a consumer item. When I took the shot CRT from that AT5005 SA recently discussed here, to drop off at the recycling place, I noticed a guy lugging a medium sized LCD TV out of his car. I was going to offer help in chucking it in the bin, but instead said I could take it - it looked pretty decent as a possible spare TV. He said it had a problem with the sound. So, it went into my truck instead of to certain destruction. With stuff like this, I can take a quick shot at fixing, but if no good, I'll strip out some parts, and it ends up with the same fate on my next trip to recycling.
I powered it up, and quickly found that the "trouble with the sound" was that the volume level insisted on going to maximum, regardless of pushing the buttons on the small local control panel on the side. No other functions worked - it was locked up because the volume up button seemed to be stuck. I figured that a cap leaked somewhere and faulted the control interface. I opened it up and found the insides quite clean, and there were no obvious signs of problems with any of the usual suspects - the Al electrolytic caps. In fact, there are none on the little button board, or anywhere around the uP periphery that could be blamed for messing up the button signals. I pulled the button board, and it seemed OK - the buttons all had good snap action. The only thing a little weird was the solder mask looked kind of flakey, so maybe there was some leakage. I was going to try washing it, but decided to first make some resistance measurements for before and after comparison. I was shocked to find that the real problem was the buttons themselves. Five out of the seven had various low resistances in their "open" state - some so low that the R didn't even change when pushed. I have never seen a problem in one of these kind of buttons before, that wasn't an obvious mechanical failure. Fortunately, I had some of the right kind in stock, so did the replacements, put it all back together, and voila, it all worked - sound too. The lesson here is that it's not necessarily always or only cap problems. I was lucky on this one, because if there were any cap problems too, it could have led to a wild goose chase fooling around with them, only to ultimately encounter the button issue. After exhausting most of my patience on caps, I likely would have assumed it was still cap juice somewhere, rather than closely looking at those buttons, and the unit would have been tossed. Ed |
|
Re: - Early Telequipment 'Scope
Hi Adrian and group,
I have an early S31 model (also pre-facelift) which I would like to give away to anyone who is interested. I also have the full, original manual with it - including parts lists, voltages and schematics. The oscilloscope basically works, producing a dispayed waveform from the CAL signal, but there are some issues with X and Y shift range and timebase linearity. The serial number on the chassis appears to 810 and the number on the transformer is 68810. This would have to be by collection only - location West Yorkshire, UK. Let me know if you are interested. Ken. |
|
I've decided what last Tek equipment I want to restore.
I've decided what last Tek equipment I want to restore. They are the
components that made up a S3100 series tester. That would complete my full circle from when I worked on Tektronix test systems starting in 1974. The S3100 is made up of the R230, R568, 3T6, 3S6. And then for programming the R240/241. If you had more money than anybody else there was even a drum memory the R250. If you have or know somebody that has any of the buff they're willing to sell trade donate etc please let me know. I am located in Portland Oregon USA. -pete |
|
FS: 17 lb. Power Transformer for Tek 545A
Over on the Facebook Vintage Electronics Group, a group member has posted that he has a transformer for a Tek 545A. Here's the text of his post. I have purchased 3 items from this seller before and he is very trustworthy.
Text of post: This beast is Tek part no. 120-120, the power transformer for the 545A 'scope. It weighs 17 pounds, has 12 secondary windings, and other than scratches on the case looks unused. I got it a few years ago when I was thinking about building a beefy audio power amp. Combined, the four high-voltage windings will supply more than 650 volts and run cool at 400 mA. It has seven 6.3 VAC windings, two rated at 8 amps, one at 6 amps, two at 4 amps, one at 1 amp and one with no rating I can find. I've checked all windings and they're good. I want to pass it along to somebody who will make use of it. I paid something like $45, as I recall. I'll sell it for $20 plus shipping. It will fit into a medium Flat Rate Box ($13.65), for a total of $33.65. Add a buck if paying by PayPal. Pickup in the Maryland suburbs of Washington DC would be fine. I'll include a table that calls out all the windings by lug number, voltage based on the 545A schematic, resistance, estimate current and power rating, and estimated loss. |
|
Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Ron
"I don't think the repair pads will do well with a leaded cap hanging on it." I have done many PCB repairs, replacing the SMD components with Leaded. See here: /g/TekScopes/album?id=60615 This is of a Bose Music system - CD-Control PCB - before and after. There is very little vertical clearance, so they lay horizontal. The SMD pads are more than large enough to accommodate the soldered leads, and as long as the soldering is kept to the same standards as for SMD caps (less than 2 secs, at 270¡ãC), there is no danger of lifting the pads. This is my standard way of working with SMD PCB's now; same process on all the TV T-Con PCB's which I work on (TV PSU PCB's are still Through-Hole). I find it super-reliable, even if it won't win any aesthetics awards, and have not experienced any comebacks at all, on any of the hundreds of SMD PCB's which I have overhauled in this way. |
|
Re: Tek 465 no display
Hi Russ,
toggle quoted message
Show quoted text
You may have overlooked my message #149053 saying "You probably downloaded more manuals now (as indicated by Dennis) if you hadn't done so already. Note that you need the manual corresponding to your S/N, below or above B250000, though the later manual shows more voltage and waveform details which may or may not be applicable to the earlier version. The requirements for regulated voltages are always in the first steps of a calibration procedure; same here. It's difficult to find the proper pages in the pdfs compared to paper manuals. Strange enough the tab "Adjustment Locations 1" in my late manual shows arrows pointing to all LV test points whereas these are missing (except +55 V) in some or all pdfs Fig. 8-19. You might consult Fig. 8-18, pdf page 236 in "tektronix_465_oscilloscope_full_sm.pdf"." You'll have to do with the available B25-up manual. There may be some minor changes in your B317000 'scope which are not yet shown in that manual, but for the present purpose don't bother about that. As said the LV requirements are always in the calibration section, here pdf page 78 of "tektronix_465_oscilloscope_full_sm.pdf". The test point locations are shown (very vaguely) in the board layout I mentioned, Fig. 8-18. Note also that the table of board grid locations below the figure. Mostly theseTPs are indicated at the board itself with description or number, like "+15V" or "TP1234". Albert On Wed, Jun 20, 2018 at 05:44 pm, <musicamex@...> wrote:
|
|
Re: 2430a power indicator lamp
At 10:08 PM 6/20/2018, Dave Casey wrote:
I don't recall it having a lamp; I thought it just has a mechanism on theThat is a Schadow switch (the line is now owned by ITT), often seen incorrectly spelt as "Shadow" switch. Dale H. Cook, Radio Contract Engineer, Roanoke/Lynchburg, VA |
|
Re: Tek 1502 Handle: How is the Blue Plastic Cap Removed?
Thank you both for your thoughts and efforts.
toggle quoted message
Show quoted text
Yes it is item #30, but the hole is larger than bolt #31. Bolt #31 directly compresses the washer #32. Since there is considerable compressive force exerted by the bolt, this avoids that force compressing plastic. I initially expected completely removing the bolt would allow the hinge to simply fall apart so I could see what was inside.? But the hinge remains intact. Then I expected the cap to be snap on, but my deliberately gentle attempts to prise it off don't move it in the slightest. I expect it probably is snap on, but given the plastic's age I'm worried that a hidden nib (etc) would break rather than deform. On 21/06/18 02:39, Artekmedia wrote:
Looking at the service manual, Figure 1, Exploded View in the mechanical parts section, if we are talking about item #30 the view shows that the bolt is all that holds it on |
|
Re: 2430a power indicator lamp
I don't recall it having a lamp; I thought it just has a mechanism on the
toggle quoted message
Show quoted text
button that exposes a bright green/yellow disc when the button is depressed. Dave Casey On Wed, Jun 20, 2018, 8:00 PM Dewey Wyatt <kn4wddewey@...> wrote:
anyone here ever replaced a 2430a indicator light? I cannot find it in the |
|
Re: Tek 1502 Handle: How is the Blue Plastic Cap Removed?
Looking at the service manual, Figure 1, Exploded View in the mechanical parts section, if we are talking about item #30 the view shows that the bolt is all that holds it on
toggle quoted message
Show quoted text
-DC manuals@... On 6/20/2018 9:13 PM, Merchison Burke via Groups.Io wrote:
If you loosen the hex-head screw in the centre of the cap, does the cap loosen? --
Dave Manuals@... www.ArtekManuals.com |
|
Re: Tek 465 no display
There is a hint in the "spec": "(It can't be used for measuring the AC power converted from a DC power with an inverter)"
toggle quoted message
Show quoted text
Inverter often means square wave or modified square wave rather than sine wave voltage. A true RMS measuring meter won't care. Also notice the total lack of an accuracy specification. And what about power factor? Dave On Wed, Jun 20, 2018 at 12:45 pm, Ed Breya wrote:
|
|
Re: Tek 1502 Handle: How is the Blue Plastic Cap Removed?
If you loosen the hex-head screw in the centre of the cap, does the cap loosen?
Does the cap look like a snap-on cap? On 2018-Jun-20 5:25 PM, Tom Gardner wrote: On 20/06/18 22:12, Raymond Domp Frank wrote:On Wed, Jun 20, 2018 at 01:40 pm, Tom Gardner wrote:It would have helped if I had noted why I wanted to remove the cap!So what is the right technique for removing the cap?Sorry, I didn't read your question, although I quoted it... Are you sure that by completely removing the bolt, you can't pull off the handle and then remove the cap "from the inside"? --- This email has been checked for viruses by AVG. |
|
Re: Tek 465 no display
Lol pol,
Thanks for the reply. Do you know where I can find a list of the lv test points and what they should read? After all of the hv warnings and having learned the hard way about hv working on tube amps, i dont want to smoke my remaining hair or my Fluke's fuses at best. If I had been inside of more than one scope[this one] and had a network of electronically competent amigos and parts at my disposal, I might not feel so overwhelmed with this repair. If you only had worked on classic hand wired tube amps and the next step was pulling the cover off a non functioning complexity like I have on the bench, you would understand how this seems to me. As an ex chemist and a charter member of 999 i am confident that i can learn how to fix this. But so far what I have downloaded from the manuals archives isn't fitting the bill by itself. Thanks, Russ |
|
Re: Tek 465 no display
The fan requires the 15V rail to be working. I'm betting your LV test points are off. The 465 I just repaired was missing the 5V the 15V and the -8V the high voltage requires that those be working so hence no CRT, the 55V and the 110V were fine. As soon as I got those working the fan started and the CRT fired up. May not be the same for you but its worth checking the LV test points. Good luck
Hi all, thanks for the replies. My sn is B 317000. But i am not having much luck in finding the downloads for this later version. The scope has several small eylet tabs on the boards labeled TP followed by a number. It would be handy if there were a page identifying the testpoints and giving a range for acceptable values. Or for example, LV circuit test points, values and troubleshooting implications for out of range values. Any help finding this info would be greatly appreciated. I will do the current measurement on the 120v input, perhaps on my off time this weekend, but as i mentioned, the power button does light the power on light and a few other lights on the front panel, and there is power to and through both fuses but there does not appear to be a filament glow inside the CRT and the fan doesn't turn on (temp activated?). Thanks, Russ |
Dale H. Cook
to navigate to use esc to dismiss