Re: Tek 4654M; No Trace, No +5V, No +95V; Help
With the 32v supply at 30v, the +/-5v readings make perfect sense as the reference
for those two regulators is the 32v supply. [30/32x 5] = 4.68v Check the DC and AC
voltages across C721. You should see around 50vdc there.
With equipment this old it is not uncommon to find multiple
failures of aluminum electrolytic capacitors which often dry out with age.
This is not true for tantalum types, however, they do not have the same age related
failure mechanism.
There won't be any +95 volts until you have 50v at C558.
Dave
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On Sat, Aug 29, 2020 at 07:07 AM, Harrison wrote:
I checked F558 and to my surprise it was blown. I know I had checked it
numerous times and it was okay. It must have blown during one of my probing
expeditions. I noted with or without F558 the unit powers up and CRT
illumination and power on light work. I lifted the outer lead of C558 and it
read 8.34 micro Farad (an in spec reading).
I was thinking of staying out of the scope for a bit and spending more time in
the manual rereading the circuit theory and operation theory. I say that
because I am confused and going in circles. After replacing C741 I had a
solid 32V, +5V and -5V at the TPs. The 95 TP read +7.58. As time has passed
those readings are now 30V, +4.7V and -4.9V. The 95V TP reads +7.5V. The
junction between CR582 and C582 reads +7.4V. These readings were all taken
with the same meter. Nothing else was done nor any other components replaced
between the two sets of readings. Monitoring the readings now for a bit it
almost seems like they discharge a bit. I.E. like a capacitor discharging.
I also noticed that immediately after replacing C741 the power on light would
illuminate steady when the power switch was pulled. Now when I pull the power
switch on it seems to blink/flicker once or twice before remaining on steady.
Granted there is a linkage and several mechanical connections that might just
be suffering the ravages of time and this might be expected.
Regardless, I am just Easter egging now and need to get smarter on the
circuits and relationship between them. Don't know where else to go from
here. Plus like I said in my first post I am a mechanical guy with limited
electrical/electronic theory schooling or background. While I read a lot, not
everything sticks.
Anyway, any and all ideas past and future are appreciated. The group has
gotten me this far. I don't know if I am close to the goal line or still off
in left field. Stay safe and healthy. Harrison N1FAM
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Re: Free 6 pin lemo cable and THS720 question
On Sat, Aug 29, 2020 at 07:32 PM, walter shawlee wrote:
TH720 Question: how can you check the battery condition? other than a low
battery message on power up,
I have yet to find any way to check this, no menu brings it up that I can see.
rats....
I assume you mean charge level, not wear-out or old age condition? Charge level can be measured (to a certain degree as voltage per cell) by measuring voltage under load but AFAIK, the THS700-series don't support that as an indication other than by just by switching - or not powering on. Since NiCd cells have a reasonably constant voltage until almost discharged, I usually took 1.05 - 1.1V as a minimum level. The indication possibilities by end-to-end measuring of a battery consisting of more than one cell in series are limited because of unknown differences in charge level. And that's just the start of it... Raymond
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On Fri, Aug 28, 2020 at 08:26 PM, Dallas Smith wrote:
The file was over 30mb's before the OCR conversion, now its 11mb's, My ABBYY
OCR software is very efficient. I think the file should be added rather than
replaced.
I think two of them are larger than 200 MB. I've reduced many Tek manuals that were over 200 MB to 30 - MB with hardly any loss of quality. If you send me an unlocked version of one of those, I'll see what "dual-layer" OCR'ing does. Raymond
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On Sat, Aug 29, 2020 at 05:44 PM, Dallas Smith wrote:
This process does not make the PDF a OCR version but just searchable The page
images do not change, it just provide information ti make the PDF searchable?
That's my preferred method: The OCR part is a separate "invisible" layer. Raymond
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Re: Free 6 pin lemo cable and THS720 question
On Sat, Aug 29, 2020 at 09:04 PM, Mark Huffstutter wrote:
I think the 6 pin Lemo cable was used to connect the TR-502 Tracking Generator
To a 7L13, Walter. I remember reading a post by Dennis too.
That cable has Lemo connectors on both sides. Raymond
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Re: Free 6 pin lemo cable and THS720 question
I think the 6 pin Lemo cable was used to connect the TR-502 Tracking Generator
To a 7L13, Walter. I remember reading a post by Dennis too.
Mark
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of walter shawlee Sent: Saturday, August 29, 2020 10:32 AM To: [email protected]Subject: [TekScopes] Free 6 pin lemo cable and THS720 question if anybody can use one,, I found another new 6 pin Lemo circular connector to tinned end cable from Tek, 20" long. I believe Dennis said these were used to link to the TR50x style tracking generators, but not sure why one end is open. In any case, free to anybody that can use it (not me), can ship in a cheap padded envelope anywhere. TH720 Question: how can you check the battery condition? other than a low battery message on power up, I have yet to find any way to check this, no menu brings it up that I can see. rats.... all the best, walter
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The electronics shop in the physics lab where I once worked just used the outer part of a BNC cable connector (removed from a connector which had had its inner portion's fingers
messed up). It works well enough if you make sure the torque is applied mostly to the panel and not to the "tool". You shouldn't apply much torque to the two posts which engage the tool
anyway. You can even use a good connector, still attached to a cable.
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Re: Tek 4654M; No Trace, No +5V, No +95V; Help
On 8/29/2020 10:07 AM, Harrison wrote: I checked F558 and to my surprise it was blown. I know I had checked it numerous times and it was okay. It must have blown during one of my probing expeditions. I noted with or without F558 the unit powers up and CRT illumination and power on light work. I lifted the outer lead of C558 and it read 8.34 micro Farad (an in spec reading).
I was thinking of staying out of the scope for a bit and spending more time in the manual rereading the circuit theory and operation theory. I say that because I am confused and going in circles. After replacing C741 I had a solid 32V, +5V and -5V at the TPs. The 95 TP read +7.58. As time has passed those readings are now 30V, +4.7V and -4.9V. The 95V TP reads +7.5V. The junction between CR582 and C582 reads +7.4V. These readings were all taken with the same meter. Nothing else was done nor any other components replaced between the two sets of readings. Monitoring the readings now for a bit it almost seems like they discharge a bit. I.E. like a capacitor discharging.
I also noticed that immediately after replacing C741 the power on light would illuminate steady when the power switch was pulled. Now when I pull the power switch on it seems to blink/flicker once or twice before remaining on steady. Granted there is a linkage and several mechanical connections that might just be suffering the ravages of time and this might be expected.
Regardless, I am just Easter egging now and need to get smarter on the circuits and relationship between them. Don't know where else to go from here. Plus like I said in my first post I am a mechanical guy with limited electrical/electronic theory schooling or background. While I read a lot, not everything sticks.
Anyway, any and all ideas past and future are appreciated. The group has gotten me this far. I don't know if I am close to the goal line or still off in left field. Stay safe and healthy. Harrison N1FAM
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Bruce, I wouldn't mind owning one of those BNC wrenches, but the link you gave doesn't ship to the UK. There is one on eBay which looks the same, but the shipping to the UK puts the cost up by an to around twice the selling-price. You say that there are "many different ones available or you can make your own..just a hole and a slot" but I can't find any others. I would also think that while making your own looks fairly easy, you probably need access to a metal-working lathe.
Colin.
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Bruce Atwood Sent: 22 August 2020 05:57 To: [email protected]Subject: Re: [TekScopes] 7A26 CH2 Readout Use a "BNC Wrench" to hold or tighten the BNC connector. There are many different ones available or you can make your own..just a hole and a slot. Here is one that looks well made but a bit pricey. I have not used this one and I'm not associated with them.
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Free 6 pin lemo cable and THS720 question
if anybody can use one,, I found another new 6 pin Lemo circular connector to tinned end cable from Tek, 20" long.
I believe Dennis said these were used to link to the TR50x style tracking generators, but not sure why one end is open.
In any case, free to anybody that can use it (not me), can ship in a cheap padded envelope anywhere.
TH720 Question: how can you check the battery condition? other than a low battery message on power up,
I have yet to find any way to check this, no menu brings it up that I can see. rats....
all the best,
walter
|
That's a slippery slope- you eventually end up with more than could possibly need or use.? Ask me how I know... ;-)
-Dave
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On Saturday, August 29, 2020, 09:09:38 AM PDT, Stephen <stephen.nabet@...> wrote: On Sat, Aug 29, 2020 at 04:50 AM, Timothy W. Koeth wrote:
Hi All,
Being the proud owner of three 556's, (and four 555s), I can give you some
historical info, $25 (2010) and $200 (2012), both were functions and
extremely clean and populated with plugins, the third a little dusty, but
operational and had the P11 CRT (2017) $50, it also had plugins.
It does come down to how badly you "need" one.? Generally those parting
with the 556 want to make sure they go to a good home as well as make a few
$$$.? I'd say no more than $200 for a clean working 556.
Hope this helps,
Tim
Tim, Thanks for the info. I don¡¯t ¡°need¡± one at all.? I have more than enough scopes for my actual needs.? I just think it looks cool. This particular model is also quite rare in Europe, and prices are usually a bit higher than in the U.S. This one is not particularly ¡°clean¡± physically, but that can be cleaned quite easily, I guess.? If it¡¯s electrically sound, that¡¯s what matters most.? It is, however, on the high side price wise.? And only comes with 2x1A1 plugins. Am I trying to convince myself??? Hmmm ?
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On Sat, Aug 29, 2020 at 04:50 AM, Timothy W. Koeth wrote:
Hi All,
Being the proud owner of three 556's, (and four 555s), I can give you some
historical info, $25 (2010) and $200 (2012), both were functions and
extremely clean and populated with plugins, the third a little dusty, but
operational and had the P11 CRT (2017) $50, it also had plugins.
It does come down to how badly you "need" one. Generally those parting
with the 556 want to make sure they go to a good home as well as make a few
$$$. I'd say no more than $200 for a clean working 556.
Hope this helps,
Tim
Tim, Thanks for the info. I don¡¯t ¡°need¡± one at all. I have more than enough scopes for my actual needs. I just think it looks cool. This particular model is also quite rare in Europe, and prices are usually a bit higher than in the U.S. This one is not particularly ¡°clean¡± physically, but that can be cleaned quite easily, I guess. If it¡¯s electrically sound, that¡¯s what matters most. It is, however, on the high side price wise. And only comes with 2x1A1 plugins. Am I trying to convince myself?? Hmmm ?
|
Hi All, Being the proud owner of three 556's, (and four 555s), I can give you some historical info, $25 (2010) and $200 (2012), both were functions and extremely clean and populated with plugins, the third a little dusty, but operational and had the P11 CRT (2017) $50, it also had plugins. It does come down to how badly you "need" one. Generally those parting with the 556 want to make sure they go to a good home as well as make a few $$$. I'd say no more than $200 for a clean working 556. Hope this helps, Tim Dr. Timothy Koeth Assistant Professor Material Science & Engineering Institute for Research in Electronics and Applied Physics University of Maryland 301-405-4952 (office) 609-577-8790 (cell) radiation.umd.edu Amateur radio call sign K0ETH "K-zero-ETH" (formerly N2LPN) On Thu, Aug 27, 2020 at 12:13 PM Colin Herbert via groups.io <colingherbert= [email protected]> wrote: Have you checked Barrytech?
OK, this entry is a bit out-of-date, but this can be a useful source of
info on Tek prices.
Colin.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of
Raymond Domp Frank
Sent: 27 August 2020 16:59
To: [email protected]
Subject: Re: [TekScopes] Type 556
On Thu, Aug 27, 2020 at 05:48 PM, Stephen wrote:
Whaooo! No, I didn¡¯t realize that at all!!
That is huge!! How much would it go for?
It consumes about the same power as its predecessor, the 555. Come to
think of it, you need both: The 555 is impressively tall, the 556 is
impressively wide.
I have no idea what it'd sell for. Some would pay a lot to get one, others
would for getting rid of theirs.
A friend of mine bought one complete a few years ago for a few hundred
euros.
Have a look at
Be prepared to become addicted and move to a bigger house.
Raymond
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Tgerbi,
Here's my ABBYY example of the 2445 manual section that you scanned,
Tektronix Serial/Model No.
Component No. Part No. Eft Dscont
Name & Description
Mfr
Code Mfr Part Number
A3R1063 313-0202-00 RES.,FXD,CMPSN:2K OHM,5%,0.25W 01121 CB2025
A3R1064 315-0202-00 RES.,FXD,CMPSN:2K OHM,5%,0.25W 01121 CB2025
A3R1065 315-0124-00 RES.,FXD,CMPSN:120K OHM,5Z,0.25W 01121 CB1245
A3R1066 315-0202-00 RES.,FXD,CMPSN:2K OHM,5Z,0.25W 01121 CB2025
A3R1067 315-0682-00 RES.,FXD,CMPSN:6.8K OHM,5Z,0.25W 01121 CB6825
A3R1068 315-0202-00 RES.,FXD,CMPSN:2K OHM,5Z,0.25W 01121 CB2025
I also have a Tektronix's 7A26 example that I could send you. This manual was scanned as image into a PDF, not searchable. Processed the manual with ABBYY to make it searchable. This process does not make the PDF a OCR version but just searchable The page images do not change, it just provide information ti make the PDF searchable? Send me your email address and I will send them to you. The total size is 20.61mb's for both files.
Dallas
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Re: Right to Repair - Re: [TekScopes] Digital scope with CRT
When it comes to safes, like lock pick sets, there is a very real fear that less than honest folks will use the information for less than legal purposes.
Now ask me about TE manufactures who keep their circuits to themselves to, as you mentioned, protect their rice bowls.
The safe folks are so guarded that to get the info on changing the combo on my fathers safe I had to provide death certificates, copies of their wills, and the court letter acknowledging I was the admin for the estate. Too much, I just kept the old combo.
Regards,
Stephen Hanselman
Datagate Systems, LLC
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On Aug 29, 2020, at 07:22, Harrison <buma7@...> wrote:
?I've followed this topic with interest for a while now. I am not at the electronic level, circuit wise that most of you are. I have had a furnace controller go out over the years and unfortunately just had them replaced. My background and forte is mechanical. I did have a similar experience is the lock smith field. I purchased a "lot" (7 or 8) file safes at a DRMO (Defense Reutilization Marketing Office) auction. Some had the Sargent combination tumbler on them. I tried to get information on line at different forums and ran into all kinds of resistance of how "only certified lock smiths can do this work", or the information is not to be shared out side the industry insiders, etc. etc. This was in spite of that there is a great deal of on-line data out there. Anyway, I never got much help from the industry and finally got things open and repaired using on-line data and trial and error. I think it was a case of "protecting the rice bowl" or "you are just not smart enough, or as smart as me" attitude. Take care, stay safe and healthy. Harrison
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Re: Right to Repair - Re: [TekScopes] Digital scope with CRT
I've followed this topic with interest for a while now. I am not at the electronic level, circuit wise that most of you are. I have had a furnace controller go out over the years and unfortunately just had them replaced. My background and forte is mechanical. I did have a similar experience is the lock smith field. I purchased a "lot" (7 or 8) file safes at a DRMO (Defense Reutilization Marketing Office) auction. Some had the Sargent combination tumbler on them. I tried to get information on line at different forums and ran into all kinds of resistance of how "only certified lock smiths can do this work", or the information is not to be shared out side the industry insiders, etc. etc. This was in spite of that there is a great deal of on-line data out there. Anyway, I never got much help from the industry and finally got things open and repaired using on-line data and trial and error. I think it was a case of "protecting the rice bowl" or "you are just not smart enough, or as smart as me" attitude. Take care, stay safe and healthy. Harrison
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Re: Tek 4654M; No Trace, No +5V, No +95V; Help
I checked F558 and to my surprise it was blown. I know I had checked it numerous times and it was okay. It must have blown during one of my probing expeditions. I noted with or without F558 the unit powers up and CRT illumination and power on light work. I lifted the outer lead of C558 and it read 8.34 micro Farad (an in spec reading).
I was thinking of staying out of the scope for a bit and spending more time in the manual rereading the circuit theory and operation theory. I say that because I am confused and going in circles. After replacing C741 I had a solid 32V, +5V and -5V at the TPs. The 95 TP read +7.58. As time has passed those readings are now 30V, +4.7V and -4.9V. The 95V TP reads +7.5V. The junction between CR582 and C582 reads +7.4V. These readings were all taken with the same meter. Nothing else was done nor any other components replaced between the two sets of readings. Monitoring the readings now for a bit it almost seems like they discharge a bit. I.E. like a capacitor discharging.
I also noticed that immediately after replacing C741 the power on light would illuminate steady when the power switch was pulled. Now when I pull the power switch on it seems to blink/flicker once or twice before remaining on steady. Granted there is a linkage and several mechanical connections that might just be suffering the ravages of time and this might be expected.
Regardless, I am just Easter egging now and need to get smarter on the circuits and relationship between them. Don't know where else to go from here. Plus like I said in my first post I am a mechanical guy with limited electrical/electronic theory schooling or background. While I read a lot, not everything sticks.
Anyway, any and all ideas past and future are appreciated. The group has gotten me this far. I don't know if I am close to the goal line or still off in left field. Stay safe and healthy. Harrison N1FAM
|
Re: Tek 7854 intermittent issues
Hi Nick,
The error is probably indicating that insufficient horizontal waveform positions were filled during acquisition. Do you also have the calculator keyboard? If so, you can set the display in "dots" mode in stead of the default "vector" mode. I guess you will see some very large horizontal gaps in the dot pattern; the slowly up going line in your second photo is merely an interpolation line (vector) between 2 dots at the end points of that line. Similar for the large horizontal line. It could, as suggested by Dave, be a power supply problem.
Are the other issues only present in digital mode or also in analog mode?
Albert
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Re: Tek 7854 intermittent issues
Check the power supplies for level and ripple. It looks like you have a
mostly digital problem, and the digital side is more susceptible to noisy
supplies than the analog.
Dave Casey
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On Fri, Aug 28, 2020, 5:06 PM Nick Corvid <awsomedrack@...> wrote: I recently got a Tektronix 7854 in seemingly great condition from a
surplus lot. On it's first power on it functioned absolutely perfect, but
now in following uses it has started to be plagued with strange
intermittent issues (No trace, no saw-tooth, no intensity control, Cal
signal wildly out of spec, ect.) but all of these issues generally subside
after a short while making it difficult to nail down the cause. Currently
the issue that is causing the most issues is the fact that the digital
acquisitions are no longer working properly when only a few days ago they
were. Now if I do a single shot acquisition it produces an error and no
saved waveform, meanwhile if I get an averaged acquisition it will still
error out but save a mangled waveform. All this is while the analog side
seems to be just fine (at the moment)
Here is a photo of the same waveform (produced by the cal. out) , both
live and average 10 digital.
Analog :
/g/TekScopes/photo/252782/0?p=Created,,,20,2,0,0
Digital :
/g/TekScopes/photo/252782/1?p=Created,,,20,2,0,0
Does anyone have any suggestions on what is wrong? I am happy to solder in
new parts if they can be had. (please don't say the tek IC's, please I beg
of you)
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Raymond Domp Frank
Mark Huffstutter
David C. Partridge