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How ti remove tek 177 Current/div switch (S130)

 

I have a broken tek 177 which I am working on.
The problem seems to be in some ranges of the current/div switch.
I was able to measure all the resistors assembled in this switch and they read as expected.
However, all the readings in the nA range are completely out.
There seems to be a short of some kind affecting these ranges.
I have used A LOT of DEOXIT in this switch at beginning of this troubleshooting.
Is it possible that the is producing this behaviour?
It seems impossible to remove the switch for a closer inspection.
The manual says it is possible to ¡°hold¡± the nut that is ¡°burried¡± inside the unit.
I tried from every position I could imagine without success.
Does anyone was able to remove this switch?
If affirmative, how?
Thanks,
Roger
TDS784A - external LCD VGA monitor is not syncing - 31,250kHz horizontal frequency problem

 

Hello,
I have a TDS784A and an old 10" CTX PanoView 540 LCD monitor. The advantage of that monitor is, that it has the native resolution 640x480, so the display is perfect pixel to pixel, if the instrument is 640x480 too. I use it without problem as external monitor for HP ESA-L1500A spectrum analyzer. But when I connected the monitor to the TDS784A, the monitor begins to blink and does not synchronize. My hypothesis is, that the CTX is a bit old and not pure "multisync" monitor, and it is not able to work with the timings from the Tektronix.

When I tried to find the basic differences between the both VGA signals, I measured the frequencies of horizontal and vertical. The HP uses horizontal freq. 31,440kHz, but the Tektronix uses 31,250kHz. When I looked to different supported timing tables for the monitors, I was not able to find the 640x480 31,250kHz horizontal frequency mode. I tried to look in the EIA 343A, but I was not able to find this information there, neither a possibility to change the timing of the VGA output on the Tektronix similarly, like it was done on the old VGA cards with multisync output.
Has anybody met with this problem and found a solution, how to adjust both VGA source and display device in case of such problems?
Best regards,
Vojtech, OK1VAW, Prague.
Re: Service Manual for a 5223 w/ Opt. 10

 

On Sat, Feb 26, 2022 at 03:30 PM, zenith5106 wrote:

H?kan,

Having _just_ referenced a much smaller bit of Tek doc that you transcribed a while ago, I'll drop in here to say it's marvelous that you have such a deep library combined with willingness to put effort into sharing parts of it that wouldn't otherwise be readily available. Thanks.

-Paul
Re: Service Manual for a 5223 w/ Opt. 10

 

Thank you H?kan. The non-option 10 manual is also quite thick, and I fully expect that the option 10 version adds a substantial amount of additional material.

I¡¯m a bit intimidated by this scope. The diagnostic flow chart looks nothing like what I have come to expect based on analog scopes of the 70s and 80s. It seems to jump right into the digital section, rather than spending any time verifying power rails and such. My scope is not showing any traces, and that sounded like a simple diagnostic process (based on my previous experience with 400- and 7000-series scopes), but I¡¯m starting to have a doubt.

¡ª Jeff Dutky
Re: 7B50 with External Single Sweep?

 

Clark,

Thanks so much for that link. I have not seen that one before. Downloaded a copy to my Tektronix folder.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Clark Foley" <clarkfoley@...>
To: "tekscopes" <[email protected]>
Sent: Saturday, February 26, 2022 8:00:24 PM
Subject: Re: [TekScopes] 7B50 with External Single Sweep?
Barry,
Take a look here. A15 is described as an output from the plugin. It indicates
the SingleSweep status of the plugin.
Re: 7B50 with External Single Sweep?

 

Barry,
Take a look here. A15 is described as an output from the plugin. It indicates the SingleSweep status of the plugin.

Re: Opinion on 'scope selection

 

Hi Harvey,
Yes, special components can pose an issue.

Lots to think about.
TNX,John

On Friday, February 25, 2022, 03:49:39 PM EST, Harvey White <madyn@...> wrote:

Don't forget parts units for things like HV transformers, power
supplies, custom ICs CRTs, FP hardware.

7904, 7103, 2430A, and TDS540A on the bench.? 2430A is mostly backup,
7103 is just in case.? work gets split between the 7904 and the TDS540A
depending on rep rate and what I need to do.

(and my wife does gourds, weaving, knitting and the like.? Has two rooms
for it.? I get no complaints)

OP?

Harvey

On 2/25/2022 3:39 PM, ¸é±ð²Ô¨¦±ð wrote:
scopes take up very little room until......the collection grows past 3
and you get into the big beauties.....unfortunately I agree you do
need 2....(especially when they are just two channel os why I have
more than 4...)...and no matter eventually you will need? a spare to
do a repair to the other.......

So the question is what does your wife like/collect? something to
consider.....potential "bribe" LOL
¸é±ð²Ô¨¦±ð



On 2/25/22 12:22 PM, Harvey White wrote:
Remember, two oscilloscopes is why your car has a spare tire.

Harvey


On 2/25/2022 3:04 PM, druid_noibn via groups.io wrote:
? Hi Paul,
Good points - yes the 453 looks to be a bit easier on the repair
side, and I de recall which end of a soldering iron to pick up. Even
better, two scopes...for repair and a back-up....my wife will kill me.

Kind regards,John

???? On Friday, February 25, 2022, 12:44:57 PM EST, Paul Amaranth
<paul@...> wrote:
? ? The 453 is easy to repair too, although the screen is small.?
Nice selection to choose from and most have good service manuals
available.

Try to get at least 2.? You need a scope to fix a scope :-)

On February 25, 2022 12:13:57 PM EST, "David C. Partridge"
<david.partridge@...> wrote:
From the point of view of ease of repair, the 465B wins.
D.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of
druid_noibn via groups.io
Sent: 25 February 2022 16:56
To: [email protected]; [email protected]
Subject: Re: [TekScopes] Opinion on 'scope selection

Hi,
It seems that there is a preference for the 2465A - I'll get that one
warmed upi soon.
Thanks,John

On Friday, February 25, 2022, 11:25:14 AM EST, satbeginner
<castellcorunas@...> wrote:

2465A (= 4ch, 350MHz) would be my choice.

















!DSPAM:62190e63113268432110409!
Re: Opinion on 'scope selection

 

Hi Dave,
OK - with hand-on-heart and a confession...I have stuff everywhere!? Heck, I have no idea why my wife puts up with me (we've know each other >50yrs).? The plan is to get a "shop" and reduce my collection of toys.? So, you are right, it is the plan.

Great idea - there are a lot of "fake" ZOOM backgrounds - I'll claim that is what it is....now outside of my "work" or if there is a visitor...OK, no visitors....I'm learning. ?

Kind regards,John

On Friday, February 25, 2022, 04:46:19 PM EST, Dave Voorhis <voorhis@...> wrote:

Sorry for veering off-topic, but I have a room for my hobbies and my other half has a room for hers. The rest of the house is ours.

It works delightfully for both of us.

My room is also my work-from-home office. On several occasions, I've reached for something behind me on a Zoom or Teams call, and someone will almost inevitably exclaim, "I thought that was some sort of fake background!? You mean all that stuff is _real_!?"

I think it looks great in my man-cave, but I can appreciate that it wouldn't be appropriate outside of it.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of ¸é±ð²Ô¨¦±ð
Sent: 25 February 2022 20:39
To: [email protected]
Subject: Re: [TekScopes] Opinion on 'scope selection

scopes take up very little room until......the collection grows past 3 and you get into the big beauties.....unfortunately I agree you do need 2....(especially when they are just two channel os why I have more than 4...)...and no matter eventually you will need? a spare to do a repair to the other.......

So the question is what does your wife like/collect? something to consider.....potential "bribe" LOL ¸é±ð²Ô¨¦±ð
Re: Opinion on 'scope selection

 

Hi ¸é±ð²Ô¨¦±ð,
I like the way you think...working on it....

Kind regards,John

On Friday, February 25, 2022, 03:39:08 PM EST, ¸é±ð²Ô¨¦±ð <k6fsb.1@...> wrote:

scopes take up very little room until......the collection grows past 3
and you get into the big beauties.....unfortunately I agree you do need
2....(especially when they are just two channel os why I have more than
4...)...and no matter eventually you will need? a spare to do a repair
to the other.......

So the question is what does your wife like/collect? something to
consider.....potential "bribe" LOL
¸é±ð²Ô¨¦±ð



On 2/25/22 12:22 PM, Harvey White wrote:
Remember, two oscilloscopes is why your car has a spare tire.

Harvey


On 2/25/2022 3:04 PM, druid_noibn via groups.io wrote:
? Hi Paul,
Good points - yes the 453 looks to be a bit easier on the repair
side, and I de recall which end of a soldering iron to pick up. Even
better, two scopes...for repair and a back-up....my wife will kill me.

Kind regards,John

???? On Friday, February 25, 2022, 12:44:57 PM EST, Paul Amaranth
<paul@...> wrote:
? ? The 453 is easy to repair too, although the screen is small.?
Nice selection to choose from and most have good service manuals
available.

Try to get at least 2.? You need a scope to fix a scope :-)

On February 25, 2022 12:13:57 PM EST, "David C. Partridge"
<david.partridge@...> wrote:
From the point of view of ease of repair, the 465B wins.
D.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of
druid_noibn via groups.io
Sent: 25 February 2022 16:56
To: [email protected]; [email protected]
Subject: Re: [TekScopes] Opinion on 'scope selection

Hi,
It seems that there is a preference for the 2465A - I'll get that one
warmed upi soon.
Thanks,John

On Friday, February 25, 2022, 11:25:14 AM EST, satbeginner
<castellcorunas@...> wrote:

2465A (= 4ch, 350MHz) would be my choice.

















!DSPAM:62190e63113268432110409!
Re: Opinion on 'scope selection

 

Hi Tom,
Had a hiccup here...
I am not yet up-to-date with the different flavors of the 2465 - learning a lot from the replies - THANKS!

Kind regards,John

On Friday, February 25, 2022, 03:24:21 PM EST, TomC <tomc@...> wrote:

The 2465 doesn't have a battery backup, unlike the 2465A and B. So you don't
have to worry about a battery that has failed, or is about to.

The two scopes on my bench are the 2465 and a 7904.

Tom


On 2/25/2022 7:38 AM, druid_noibn via groups.io wrote:
An opinion please.? A friend is offing me a choice of one of his Tek scopes: 453, 465B, 2236, 2246, 2445, 2445B, 2465, 2465A, and a THS730A.? His plan is to sell-off the inventory¡­he has a lot of ¡°stuff¡± and we have retirement.

We all know that a working ¡°A¡± is far better than a non-working ¡°B¡± and I have not evaluated the items yet but would like an opinion or two on which would be a ¡°preferred¡± for an experienced hobbyist.

Kind regards,
John
Re: Opinion on 'scope selection

 

Hi Harvey,
Most excellent....FYI, my Dodge Caravan didn't come with a spare...<smile>...I wish it did.

Tnx,John

On Friday, February 25, 2022, 03:22:36 PM EST, Harvey White <madyn@...> wrote:

Remember, two oscilloscopes is why your car has a spare tire.

Harvey


On 2/25/2022 3:04 PM, druid_noibn via groups.io wrote:
? Hi Paul,
Good points - yes the 453 looks to be a bit easier on the repair side, and I de recall which end of a soldering iron to pick up.? Even better, two scopes...for repair and a back-up....my wife will kill me.

Kind regards,John

? ? ? On Friday, February 25, 2022, 12:44:57 PM EST, Paul Amaranth <paul@...> wrote:
?
? The 453 is easy to repair too, although the screen is small.? Nice selection to choose from and most have good service manuals available.

Try to get at least 2.? You need a scope to fix a scope :-)

On February 25, 2022 12:13:57 PM EST, "David C. Partridge" <david.partridge@...> wrote:
From the point of view of ease of repair, the 465B wins.
D.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of
druid_noibn via groups.io
Sent: 25 February 2022 16:56
To: [email protected]; [email protected]
Subject: Re: [TekScopes] Opinion on 'scope selection

Hi,
It seems that there is a preference for the 2465A - I'll get that one
warmed upi soon.
Thanks,John

On Friday, February 25, 2022, 11:25:14 AM EST, satbeginner
<castellcorunas@...> wrote:

2465A (= 4ch, 350MHz) would be my choice.





? ?












!DSPAM:62190e63113268432110409!
Re: Opinion on 'scope selection

 

Hi Brad,
Don't plan on climbing ladders and the like - but the point of portability might be a consideration to negotiate for a second scope...e.g., the THS730A...as a back-up of course.

Did not consider data capture...hmmmm

Tnx OM,John

On Friday, February 25, 2022, 03:17:56 PM EST, Brad Thompson <brad.thompsonaa1ip@...> wrote:


On 2/25/2022 11:06 AM, Dave Voorhis wrote:
Speaking as a collector, with a collection that started in 2016 with a 475 (I'm not counting a forgettable modern DSO) and has since grown to twenty oscilloscopes and curve tracers, I suggest attempting to obtain all of them. ?

But assuming only one...
Hello--

A couple of questions: will you need to tote the scope

up ladders or many flights of stairs? That argues for lower weight and
smaller size.

Also, scopes with built-in data capture are convenient, but make sure
that you can find a

utility that runs? on your personal computer of choice.

73--

Brad? AA1IP




-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of druid_noibn via groups.io
Sent: 25 February 2022 15:38
To: [email protected]
Subject: [TekScopes] Opinion on 'scope selection

An opinion please.? A friend is offing me a choice of one of his Tek scopes: 453, 465B, 2236, 2246, 2445, 2445B, 2465, 2465A, and a THS730A.? His plan is to sell-off the inventory¡­he has a lot of ¡°stuff¡± and we have retirement.

We all know that a working ¡°A¡± is far better than a non-working ¡°B¡± and I have not evaluated the items yet but would like an opinion or two on which would be a ¡°preferred¡± for an experienced hobbyist.

Kind regards,
John
Re: Service Manual for a 5223 w/ Opt. 10

 

On Sat, Feb 26, 2022 at 07:01 AM, Jeff Dutky wrote:


Does anyone have a service manual for the 5223 Opt. 10
I have it and I have started to scan it. It is quite a thick one with a lot of fold out pages so it'll take a day or two.
I'll let you know when it's done.
/H?kan
Re: Cleaning 7A26 contacts

 

Hi Karin,

As with several Tek models, the 7A26 attenuator has polyphenylene oxide (PPO) boards. Aside from its low melting temp, it is sensitive to certain common solvents. I use isopropyl alcohol to clean attenuator contacts. It works well, it's cheaper than Deoxit, and is well tolerated by PCB materials. And it's even officially recommended by Tek.

-- Cheers,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070

On 2/26/2022 10:26, Karin Johnson wrote:
I am servicing a 7A26 and have a question about using DEOXIT D100 on the attenuator sping leaf contacts. In the 7A26 service manual there is a statement as follows:
"Do not apply any solvent containing ketones, esters,or halogenated hydrocarbons."

The MSDS safety sheet for D100 has a statement about the odor (ie:("Ehtereal / hydrocarbon odor").

Given the word "hydrocarbon odor" in the MSDS sheet, I am wondering if DEOXIT D100 is safe to use
on the circuit board containing the spring leaf switches????
Any suggestions????
Karin Anne Johnson
Palm Harbor, FL
Re: Cleaning 7A26 contacts

 

The attenuators in TEK plug-ins are super sensitive, some of the PCB substrate is polysolfone

99% Isopropyl alcohol may be the only approved wash.

Deoxit, contact cleaners, almost anything else sill damages the plug-in

Jon
Re: Have I blown up my scope??

 

Earlier I wrote...

It's tempting to do a re-cap on the basis that "I might as well do it while it's out of the 'scope", especially as these PSU's are not the easiest to extract from the chassis and disassemble to work on but I am not sure I would rush into a blanket replacement of the existing caps unless you know that there is a problem.
I should have known better, I suppose, than to tempt fate :)

The 10?F 100V caps looked and measured OK and I left them in situ, the two 180?F caps for the +/- 15V unregulated lines had high ESR (strictly one ended up with infinite ESR as one of its leads fell out when removing it from the PCB), the 250?F caps decoupling the 5V rails measured OK but the bottom red plug was bulging a lot (normal??) so I swapped those, all of the 100?F 25V caps measured absolutely fine as well but I could see evidence of electrolyte leakage around the rubber bung so they all got replaced.

New caps were Nichicon UPW/UPM/UPJ on the inverter board and general purpose Nichicons (UKL's) on the regulator board - apart from C1130 where I used a "high ripple current" part.

So much for "if it ain't broke, don't fix it".

The scary bit will be reassembling it and hoping that it does not go "bang".

--
Paul
Re: sick 7D20

 

Hit right on the spot!

The 0216 and 0032 are identical.
The datasheets for both chips are on TekWiki and they are both M55D amplifiers, as the chip shematic is included, you can see that they are identical in values and process of their silicone.
Thanks for the Tip, it was Gold!

Benedikt
Re: Cleaning 7A26 contacts

 

Karin,
I will send you some information off list.

Zen

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Karin Johnson
Sent: Saturday, February 26, 2022 1:27 PM
To: [email protected]
Subject: [TekScopes] Cleaning 7A26 contacts

I am servicing a 7A26 and have a question about using DEOXIT D100 on the attenuator sping leaf contacts. In the 7A26 service manual there is a statement as follows:
"Do not apply any solvent containing ketones, esters,or halogenated hydrocarbons."

The MSDS safety sheet for D100 has a statement about the odor (ie:("Ehtereal / hydrocarbon odor").

Given the word "hydrocarbon odor" in the MSDS sheet, I am wondering if DEOXIT D100 is safe to use on the circuit board containing the spring leaf switches????
Any suggestions????
Karin Anne Johnson
Palm Harbor, FL
Cleaning 7A26 contacts

 

I am servicing a 7A26 and have a question about using DEOXIT D100 on the attenuator sping leaf contacts. In the 7A26 service manual there is a statement as follows:
"Do not apply any solvent containing ketones, esters,or halogenated hydrocarbons."

The MSDS safety sheet for D100 has a statement about the odor (ie:("Ehtereal / hydrocarbon odor").

Given the word "hydrocarbon odor" in the MSDS sheet, I am wondering if DEOXIT D100 is safe to use
on the circuit board containing the spring leaf switches????
Any suggestions????
Karin Anne Johnson
Palm Harbor, FL
Re: sick 7D20

 

Hi Benedikt ,?I had the same problem for a number of years with the input amp being intermittent , when I finally got time to fix it I could not find a source for the 0216 chip , in desperation I robbed an 0032 amp from an old 7A12 parts unit -- it works a treat and in this case I did not even need to do much regarding calibration afterwards . Maybe it will work for you too .

good luckBrian (UK)

On Saturday, 26 February 2022, 18:08:48 GMT, Benedikt Dienst <bene.dienst@...> wrote:

HI,

I'm repairing a sick 7D20 for a friend and I'm almost finished. Sadly one of the unobtanium input Amplifiers (155-0216-00) has gone bad and neither fleabay nor the canadian connection seems to have any.
Is someone in the group able to help?

regards
Benedikt
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