Re: Bunch of FREE vintage test equipment in NH (USA)
Posting deleted by its author. (9:30 AM)
Roy Morgan
K1LKY Western Mass
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On Sep 27, 2020, at 3:51 AM, Jay Walling via groups.io <jayw_comark@...> wrote:
?
No affiliation. Good luck!
Jay
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Re: 547 Repair - how do you locate where parts are located on ceramic strips?
On Sun, Sep 27, 2020 at 02:39 AM, Dave Wise wrote:
Perhaps you (Raymond) are thinking of TO-105 and TO-106, another early plastic
package using an epoxy-capped ceramic header which put the leads in a circle a
la TO-5 and TO-18, respectively.
I should have explained that I meant the coplanar TO-92 leads came bent that way in some cases, just outside the package. Of course, being European, we mostly used BCxxx and BFxxx (Pro-Electron) devices. None of that 2N3904 etc. stuff... We encountered very few TO-105/106 devices, mostly Fairchild but they were uncommon and hardly if ever available in component shops. I'm sure most devices that looked like those (ceramic header with epoxy top) were uL 914 RTL dual NOR gates.... - also Fairchild of course. That was 1965-1970... Raymond
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Re: Tek 7854 intermittent issues
I *THINK* that you can safely power the scope without the digital boards installed. but I never tried that.
Does anyone know if it's OK to do that? I can't think of any potential nasties except possibly an insanely bright spot in the centre of the CRT causing screen burn which you can mitigate by disconnecting one of the vertical deflection leads from the CRT which will put the trace off screen.
I know there's a test board that you can install to make it operate as an analogue 'scope, but I don't have one. Did anyone ever do Gerber files for that board?
David
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Nick Corvid Sent: 27 September 2020 05:01 To: [email protected]Subject: Re: [TekScopes] Tek 7854 intermittent issues I was measuring the -5 off one of the pins off the motherboard leading to the digitizer board, I can see what's going on with TP92 and see if it's the same. Also I guess I'll pull all the cards again and get access to the digital supply board and check all the caps.
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Re: FS: Tektronix DPO4104 1GHz 5GS/s 4CH
THIS IS A SCAM !!!!
Not only that. They are now also getting back claiming to be the FBI
via a fake address info@.... They say the man behind it has
been arrested and they want to compesate you with a silly amount of money,
BUT you need to pay an 'insurance fee' of $400 to get your money !
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Bunch of FREE vintage test equipment in NH (USA)
No affiliation. Good luck!
Jay
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Re: Tek 7854 intermittent issues
I was measuring the -5 off one of the pins off the motherboard leading to the digitizer board, I can see what's going on with TP92 and see if it's the same. Also I guess I'll pull all the cards again and get access to the digital supply board and check all the caps.
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Re: 547 Repair - how do you locate where parts are located on ceramic strips?
The 2N2207 has a case style that became obsolete later, a metal cylinder with coplanar leads. Holding the transistor so the leads point down and the ones that are close together on the left, it's E-B--C. Collector is distant from the others. Some transistors in this case style brought out the case to a fourth lead. Those are E-B-case--C. They shielded C from B quite well, for neutralized common-emitter RF amplifiers. TO-92: holding it with the flat facing you and leads down, most transistors with 2Nxxx JEDEC numbers are E-B-C, while most BCxxx Pro-Electron's are C-B-E. (And most Asian 2Sxxx are E-C-B. Never a dull moment!) TO-92, and TO-98 ("plastic circular bottom with flat side on top section") parts always have coplanar leads. Perhaps you (Raymond) are thinking of TO-105 and TO-106, another early plastic package using an epoxy-capped ceramic header which put the leads in a circle a la TO-5 and TO-18, respectively. TO-92 won the race because it's cheaper to make. Stamped lead frame, attach die, wire bond, jig it into the mold, inject, cut the lead joins and you're done. Dave Wise ________________________________________ From: [email protected] < [email protected]> on behalf of Raymond Domp Frank via groups.io <hewpatek@...> Sent: Saturday, September 26, 2020 5:15 PM To: [email protected]Subject: Re: [TekScopes] 547 Repair - how do you locate where parts are located on ceramic strips? On Sun, Sep 27, 2020 at 01:29 AM, Chuck Harris wrote:
For future reference, there are only a very small handful of ways nonpower
transistors of that era were leaded:
Plastic
-------
---
/EBC\ TO92 Plastic
\.../
---
(ECB) plastic circular bottom with flat side on top section
Metal Can
---------
(EBS C) Metal can w/wo case = S
B
(E C) Metal can w/wo emitter tab
//
B
(E C) Metal can with emitter tab and case = S
//S
And that is it.
Text mode makes layout a bit confusing, on my screen at least, especially for the plastics. One might add the layouts are all bottom view. Some TO-92's have a triangular lead configuration like the metal cans TO-5, TO-39, TO-72. Bottom/top view distinction is clear for the cases with emitter tabs and irrelevant for the linear arrangements. By far the most common cases were TO-5, TO-39, TO-72 and TO-92. The flat side of the latter corresponds with the "empty" area on the metal cans' pin layout, leading to the same CBE-arrangement, which is why I considered that the "standard" arrangement. Raymond
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Re: 547 Repair - how do you locate where parts are located on ceramic strips?
On Sun, Sep 27, 2020 at 01:29 AM, Chuck Harris wrote:
For future reference, there are only a very small handful of ways nonpower
transistors of that era were leaded:
Plastic
-------
---
/EBC\ TO92 Plastic
\.../
---
(ECB) plastic circular bottom with flat side on top section
Metal Can
---------
(EBS C) Metal can w/wo case = S
B
(E C) Metal can w/wo emitter tab
//
B
(E C) Metal can with emitter tab and case = S
//S
And that is it.
Text mode makes layout a bit confusing, on my screen at least, especially for the plastics. One might add the layouts are all bottom view. Some TO-92's have a triangular lead configuration like the metal cans TO-5, TO-39, TO-72. Bottom/top view distinction is clear for the cases with emitter tabs and irrelevant for the linear arrangements. By far the most common cases were TO-5, TO-39, TO-72 and TO-92. The flat side of the latter corresponds with the "empty" area on the metal cans' pin layout, leading to the same CBE-arrangement, which is why I considered that the "standard" arrangement. Raymond
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Re: 547 Repair - how do you locate where parts are located on ceramic strips?
The scoundrels!
I guess they hadn't started that tradition yet when the 545B and 547
were made.
For future reference, there are only a very small handful of ways nonpower
transistors of that era were leaded:
Plastic
-------
---
/EBC\ TO92 Plastic
\.../
---
(ECB) plastic circular bottom with flat side on top section
Metal Can
---------
(EBS C) Metal can w/wo case = S
B
(E C) Metal can w/wo emitter tab
//
B
(E C) Metal can with emitter tab and case = S
//S
And that is it.
Grayson Evans wrote:
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HA! Thanks Chuck, I went through my 547 manual, front to back, and I don't see it anywhere,
but I answered my own questions, I found a 2207 that I could see the socket clear enough and traced it out.
THen I replace the 2207's with BC556's and it works! So i guess I got the pin outs right for a change.
Thanks,
Grayson Evans
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Re: 547 Repair - how do you locate where parts are located on ceramic strips?
HA! Thanks Chuck, I went through my 547 manual, front to back, and I don't see it anywhere,
but I answered my own questions, I found a 2207 that I could see the socket clear enough and traced it out.
THen I replace the 2207's with BC556's and it works! So i guess I got the pin outs right for a change.
Thanks,
Grayson Evans
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Re: 547 Repair - how do you locate where parts are located on ceramic strips?
Hello Dave,
I answered my previous questions from earlier today. I found a 2N2207 that I COULD see the connections and traced it out.
So I replaced Q173 and Q184 with BC556 and bingo, fixed the unblanking problem. I haven't paralleled C170 yet, but will do that next.
Thanks for your help and the rest of the guys on this board!
Grayson
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Tek 485 Knob--B Time/Div and Delay Time 366-1385-00
Hi folks,
I've been unable to chase down this knob for my 485. It's 366-1385-00. Similar to other knobs for this purpose, but with a "skirt" at the base, without which, it's more difficult to tell what the setting is due to large parallax. Not urgent, as mine works with part of the skirt broken off, but the aesthetics are lousy. Any help?
Also, I'd like to find seven of the 366-0215-02 lever switch knobs for the same scope. Again, of course it works without them, but I'd like the scope better if the levers wore mittens!
Thanks,
Bruce
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Re: 465B Horizontal Trace Issues - Help requested
All I can convey is what I've learned from decades of fixing scopes (I own almost 200 of them, and perhaps a dozen or so 465/465B and related models). By far the most common sources of trouble are the two that I've mentioned: Flaky contacts (which afflict pretty much all vintage electronics), and tantalum capacitors. Sure, other things go wrong, too, but those two dominate by far, so I spend a little time exploring those first before moving on down the list.
Tek seems to have purchased a bad (and large) batch of tantalum caps in that era, so when I see a failure on the output side of the PS, I no longer spend a lot of time checking. It's much faster to replace the tants on the afflicted rail(s). There are not that many, thank goodness, and they are easy to access and replace. If I see a problem on the input side, it's easy enough to see if there are failed rectifiers or a bad primary cap. The latter are a bit of a PITA to replace (certainly compared to tants), but still readily doable. But you aren't having a problem with the primary side of the PS, and it isn't even clear that you have a PS problem of any kind.
I share your disdain for shotgunning. However the problem here is that you appear to lack the necessary instrumentation to perform more detailed investigations, and you are also reluctant to disassemble things much. That severely limits what you can accomplish. It's hard to advise you how to proceed, given the overly constrained set of steps you are willing/able to take. So, I'll limit my comments to what I would do, and you are free to ignore my advice, whether for taste, or lack of tools.
Put the scope in x-y mode (to bypass all the sweep generator circuits) and drive both x and y with the calibration source on the front panel (it's just a handy signal source). If you still see width compression there, the problem is downstream of the sweep generator. If you no longer see width compression, then the problem lies before the deflection amplifier.
Wherever the problem lies, I would use Deoxit (don't flood; a little will do a lot) on all connectors to/from the horizontal circuitry, and the pushbutton switches (these have often been a source of maddening problems for me). If the first step revealed a problem with the sweep generator, note that I have also sprayed Deoxit on the contact fingers of the sweep speed knob, despite warnings that it may be a bad idea (I have never done so on the vertical attenuator fingers, though, where the danger of affecting the transient response is much higher). Like you, the prospect of disassembling the whole thing to do it the factory-recommended way (sliding strips of paper soaked in IPA between each contact pair) seems unattractive. I do it anyway, and have not had any problems. Of course, I have the luxury of many spare scopes, so you may have a different tolerance for gambling. Proceed at your own risk.
I would reseat all ICs on the relevant boards, and carefully inspect all pins and socket contacts in doing so. Depending on the environment in which the scope was used/stored, weird corrosion can occur. Carefully clean any contacts that look dodgy.
If none of the foregoing fixes things, I would monitor the power supply voltages and watch for dips (problems from spikes are rare). I long ago jimmied up a simple comparator-and-latch gizmo that does the watching for me. Set the lower voltage limit (e.g., 20% below nominal; you're not looking for tiny effects here), hook it up to the rail in question, and go watch Netflix. If the supply ever dips below the set threshold, an LED illuminates (and stays on), letting you know that that rail is flaky. Replace tantalum. Repeat. You can monitor several rails simultaneously; the monitoring circuit is simple to build.
Or just replace the tants on the board(s) in question. It won't take much time.
Good luck. The 465B is a nice scope, and well worth fixing up.
--Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
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On 9/26/2020 13:00, gary@... wrote: Moving or jiggling the time base switch (Time/Div and Delay Time switch) has no effect on the problem. I have not cleaned it as it is difficult to get to, even after lifting the DM44 module.
Regarding the tantalum caps, I have read that these can be problematic, but not ready to start replacing parts that may not be related to the problem. However, I do restoration of 30-50 year old audio gear, and replacement of electrolytic caps is pretty much the starting point, so I understand replacing caps that simply due to age, are likely to be bad, marginal, or will go bad soon. However due to the complexity of the 465B, I am reluctant to take this apart unless there is a goal (finding my problem - something specific to check and either identify or rule out) -- perhaps that is too much to expect.
However, the reason I am asking for your time and tapping the experience and wisdom on this group, is to proceed based on that wisdom, rather than blindly. If that experience indicates that I should start by replacing certain caps (e.g. the electrolytics in the PS, and some/all tantalums), then I will gather up the gumption to do so - and will need to ask more questions. But taking on this task and then finding I still have the compression problem, while giving me a more "stable" scope, does not really fix the problem. I would rather find/fix the problem, and then with the knowledge that my scope does not have a major deficiency, address the (potential) issue of the caps. Is this thinking backwards?
Thanks to all for your patience and advice.
Gary
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Re: 547 Repair - how do you locate where parts are located on ceramic strips?
Tektronix usually puts the transistor pin-outs in the
front of the maintenance section... You know, all of that
stuff that nobody reads.
-Chuck Harris
Grayson Evans wrote:
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Hello Dave,
I order several BC566's to replace the 2N2207. Do you have any idea what the pin-out is on the 2N2207. I have searched the internet but can't find a data sheet on the 2207. i assume on of the leads is the case, I can't even see the back of the sockets due their being right under the parts on the ceramic strips.
Thanks !
Grayson
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Re: 547 Repair - how do you locate where parts are located on ceramic strips?
Hello Dave,
I order several BC566's to replace the 2N2207. Do you have any idea what the pin-out is on the 2N2207. I have searched the internet but can't find a data sheet on the 2207. i assume on of the leads is the case, I can't even see the back of the sockets due their being right under the parts on the ceramic strips.
Thanks !
Grayson
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Re: 465B Horizontal Trace Issues - Help requested
Moving or jiggling the time base switch (Time/Div and Delay Time switch) has no effect on the problem. I have not cleaned it as it is difficult to get to, even after lifting the DM44 module.
Regarding the tantalum caps, I have read that these can be problematic, but not ready to start replacing parts that may not be related to the problem. However, I do restoration of 30-50 year old audio gear, and replacement of electrolytic caps is pretty much the starting point, so I understand replacing caps that simply due to age, are likely to be bad, marginal, or will go bad soon. However due to the complexity of the 465B, I am reluctant to take this apart unless there is a goal (finding my problem - something specific to check and either identify or rule out) -- perhaps that is too much to expect.
However, the reason I am asking for your time and tapping the experience and wisdom on this group, is to proceed based on that wisdom, rather than blindly. If that experience indicates that I should start by replacing certain caps (e.g. the electrolytics in the PS, and some/all tantalums), then I will gather up the gumption to do so - and will need to ask more questions. But taking on this task and then finding I still have the compression problem, while giving me a more "stable" scope, does not really fix the problem. I would rather find/fix the problem, and then with the knowledge that my scope does not have a major deficiency, address the (potential) issue of the caps. Is this thinking backwards?
Thanks to all for your patience and advice.
Gary
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Re: TDS5/6/700 application software packages?
If anyone does find them, I would offer a reminder to please upload
copies to Didier's archive site. I can make them available at my end as
well, once they're located.
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On 26-Sep-20 12:41, EricJ via groups.io wrote: Never have seen the disks available anywhere but sure would like to get my
hands on them.
--Eric
On Fri, Sep 25, 2020, 11:55 AM Siggi <siggi@...> wrote:
Hey y'all,
I've always been curious to see the applications that were available for my
TDS784D back in the day. Have any of you even seen these applications, or
know where I might find them?
In the datasheet on Tek's website, the applications are described thusly:
--
---
Bruce Lane, ARS KC7GR
kyrrin (at) bluefeathertech dot com
"Quando Omni Flunkus Moritati" (Red Green)
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Re: TDS5/6/700 application software packages?
Never have seen the disks available anywhere but sure would like to get my
hands on them.
--Eric
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On Fri, Sep 25, 2020, 11:55 AM Siggi <siggi@...> wrote: Hey y'all,
I've always been curious to see the applications that were available for my
TDS784D back in the day. Have any of you even seen these applications, or
know where I might find them?
In the datasheet on Tek's website, the applications are described thusly:
"Application Software Packages
These Java based application packages reduce the cost, time and complexity
common to many application-specific test procedures. These
application-specific capabilities are easily installed via floppy disks and
require a hard disk drive (Option HD or Option 2M).
TDSPWR1 gives designers interested in power consumption applications the
ability to automatically calculate True Power, Apparent Power, Power
Factor, Instantaneous Power and Energy to eliminate manual calculations.
TDSJIT1V2 performs a suite of jitter measurements with unprecedented
accuracy on single-shot waveforms. Jitter information can be displayed as
statistics, histograms, time trends or jitter spectrums.
This software makes timing measurements by providing statistics on
specific, fully time-correlated data and clock edges. It also performs
automated AC timing measurements on all parameters in single-shot
acquisitions.
TDSCEM1 performs a suite of automated eye diagram measurements on SONET/SDH
and Fibre Channel standards. These measurements include eye height, eye
width and quality factor.
TDSCPM1 performs automated parametric measurements of pulse amplitude,
spectral power and pulse symmetry to standards requirements. Standards
include ANSI T1.102 and ITU-T G.703."
Siggi
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Re: 465B Horizontal Trace Issues - Help requested
What you have sounds like a classic intermittent.
Thinking of the possibilities, and since the power supply voltages are constant.
1) intermittent contact. That could be a power supply into the board.
2) intermittent contact. That could be a transistor/IC in a socket.
3) intermittent capacitor. Not so likely unless it's in a supply filter, and I'd think once failed, it wouldn't open back up again.
4) intermittent transistor: Generally, they fail and that's that unless somehow they're leaky or noisy.
5) intermittent resistor: Can happen, you'd have to monitor voltages.
6) intermittent Pot: Some of the pots are direct gain or centering controls.
7: Intermittent contact: switches.... x1 x10 gain typically.
Generally, you pull the parts that can be pulled, transistors, that is, and put them back in. Ditto for the connectors.
For the pots, I'd look particularly at the gain adjust pots and look to see what voltages (you could measure with a meter, but even better would be the scope's vertical channel. (which is behaving). If you don't have a horizontal problem (and I'd use your function generator to put in a 1 Khz sine to the horizontal channel. Pick a point where you want to monitor, hook the vertical to there (adjust vertical gain for 45 degree slope), and watch what happens.
If the point you monitor is changing, then the angle of the line won't change, but the vertical and horizontal size will. If the point doesn't change, then the angle will change and the vertical deflection won't.
Mark the position of the gain pots, and tweak them very slightly to see if that solves the problem.
Monitoring is your best option, right after making sure there are not intermittent contacts.
Harvey
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On 9/26/2020 1:56 PM, gary@... wrote: I adjusted the +55V to exactly +55.0, and the other voltages fell in line. I attempted to measure the ripple with the scope, but not sure of the results. At the +110 TP I think i was getting about 15mV, vs. a spec of 20mV. At the lower magnitude voltages the ripple was to small for me to determine a value, but if i had to guess it looked to be lower than spec. Not sure I was set up right, so I measured ripple on a 12v wall wart, as a test, and those measurements seemed to be working.
So let's assume my PS low voltages and ripple are OK, or are at least not so out of wack that I do not need to replace the PS caps - for now.
I am still getting the compressed trace, intermittently.
As far as other equipment, I do not have a function generator, only an audio frequency generator that to up to 100k Hz, and I am in the process of overhauling that. Before I call in favors, I would like to do some more checking.
Anyone have any ideas?
Thanks, Gary
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Re: 465B Horizontal Trace Issues - Help requested
(Sorry if these have already been suggested -- I haven't read the whole thread): Have you tried cleaning the timebase switch contacts? Does jiggling the switch have any effect on what you see?
Also, I have (rarely) encountered self-resetting tantalums. A tant generally fails as a hard, almost superconducting, short, as I'm sure you know. But I've come across a couple that would intermittently short and sort of self-heal before ultimately shorting forever. It's a low probability phenomenon, so I'd only consider it after eliminating the usual suspects.
Good luck!
--Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
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On 9/26/2020 10:56, gary@... wrote: I adjusted the +55V to exactly +55.0, and the other voltages fell in line. I attempted to measure the ripple with the scope, but not sure of the results. At the +110 TP I think i was getting about 15mV, vs. a spec of 20mV. At the lower magnitude voltages the ripple was to small for me to determine a value, but if i had to guess it looked to be lower than spec. Not sure I was set up right, so I measured ripple on a 12v wall wart, as a test, and those measurements seemed to be working.
So let's assume my PS low voltages and ripple are OK, or are at least not so out of wack that I do not need to replace the PS caps - for now.
I am still getting the compressed trace, intermittently.
As far as other equipment, I do not have a function generator, only an audio frequency generator that to up to 100k Hz, and I am in the process of overhauling that. Before I call in favors, I would like to do some more checking.
Anyone have any ideas?
Thanks, Gary
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Raymond Domp Frank
David C. Partridge
Perdad
Bruce Lane