Date   
Re: Tek 7603 Followed Me Home

Dave Daniel
 

This is obvious, but make sure that the fuse is installed and of the correct rating.

DaveD

On 9/9/2018 9:22 AM, Robert Hay wrote:
So far no plugins and the light isn't lit.  I'll check it.

Bob.


On 9/8/2018 7:43 PM, Robert Hay wrote:
I have seen this Tek 7603 scope sitting on the table at the Tek Country store for at least three years.  I have tried to power it up and twist some knobs several times over the years with no response.  They have been asking $35 for it and I noticed today there are about 5-6 price stickers stacked up under the current one.

I have been thinking a 7603 would fit into my ensemble if I clear space for it by giving another scope to the Tek Museum. So, I asked if they would take $25 for it and they did.  So, here it sits with the covers off and the power supply hanging out the back.  It doesn't do nut-tin when powered up.

The main fuse, the fuse on the regulator board and the one on the power supply board above the caps are good. I checked the power supply voltages on the regulator board with the following results:

Volt        VDC      VAC
130       114          11
50            44           5
5            4.396       0.25
15           13.2        1.4
-15         -13.17      1.3
-50          -44          4.8

Unregulated Voltages

50           66            0.16
-50        -52              13
15           24              0.04
-15       -24               0.1
5           12.4             0.05

Seems to be discrepancies between the ripple on the corresponding regulated and unregulated supplies which I don't understand.

The 130 volt supply is partly made up from the 50 volt supply and the voltage on the emitter of Q850 should add about 40 volts but I measure 10.8 volts DC there.  Maybe I see it now, if the 50v supply is at 44 volts there is no way the emitter of Q850 can get to 40 v.

I appreciate any ideas from folks especially those who have been thru a 7603 before.  Haven't had a chance to research the archive but will do that before doing more troubleshooting.  I can't take another scope to the Tek Museum until I know we can bring this one back to service.

Bob.






Re: Tek 7603 Followed Me Home

Chuck Harris
 

No plugins, and the scope will do nothing.
The little green lights burn out all of the
time.

The manual tells you everything you need to
know about power supply diagnosis. It is
expecting that you will make DC measurements
with a DVM, and ripple measurements with another
scope, set to LINE trigger, and sweep at 5ms/div.

In this mode, ripple will be stationary.

The really high frequency glitches on the power
can be ignored, but the 60Hz and 120Hz ripple
are important, as are the general noise level.

The unregulated outputs are not critical as
to value, but do need to be close. They are
not especially critical as to ripple, expect
high values. Their purpose is to feed regulators.

They will vary greatly depending on your mains
voltage, and the mains setting of the scope.

The 7603 has a linear power supply. All of the
regulators are referenced to the -50V regulated
supply. You show it way off, everything else will
be off proportionately. Fix it first. Don't just
adjust it, fix it.

-Chuck Harris

Robert Hay wrote:

So far no plugins and the light isn't lit. I'll check it.

Bob.


On 9/8/2018 7:43 PM, Robert Hay wrote:
I have seen this Tek 7603 scope sitting on the table at the Tek Country store for
at least three years. I have tried to power it up and twist some knobs several
times over the years with no response. They have been asking $35 for it and I
noticed today there are about 5-6 price stickers stacked up under the current one.

I have been thinking a 7603 would fit into my ensemble if I clear space for it by
giving another scope to the Tek Museum. So, I asked if they would take $25 for it
and they did. So, here it sits with the covers off and the power supply hanging
out the back. It doesn't do nut-tin when powered up.

The main fuse, the fuse on the regulator board and the one on the power supply
board above the caps are good. I checked the power supply voltages on the regulator
board with the following results:

Volt VDC VAC
130 114 11
50 44 5
5 4.396 0.25
15 13.2 1.4
-15 -13.17 1.3
-50 -44 4.8

Unregulated Voltages

50 66 0.16
-50 -52 13
15 24 0.04
-15 -24 0.1
5 12.4 0.05

Seems to be discrepancies between the ripple on the corresponding regulated and
unregulated supplies which I don't understand.

The 130 volt supply is partly made up from the 50 volt supply and the voltage on
the emitter of Q850 should add about 40 volts but I measure 10.8 volts DC there.
Maybe I see it now, if the 50v supply is at 44 volts there is no way the emitter of
Q850 can get to 40 v.

I appreciate any ideas from folks especially those who have been thru a 7603
before. Haven't had a chance to research the archive but will do that before doing
more troubleshooting. I can't take another scope to the Tek Museum until I know we
can bring this one back to service.

Bob.








Re: Tek 7603 Followed Me Home

bobh@joba.com
 

Chuck & Dave,

The fuses are good.  The jumper for 120/240 is there but not connected on one end.  I think this is correct since the three position plug seems to also parallel the windings for 120v.

I had tried a 7A22 & a 7B50 but the 7B50 is probably bad so I replaced it with a 7B53A and I now have some lights on the plug-ins and graticle light.  No trace, but moving the trigger knob does cause the trigger light to flicker as expected.

I can't work on it again until this evening.  I'll re-check the voltages and check the ripple(s) with another scope.

Bob.

On 9/9/2018 7:36 AM, Chuck Harris wrote:
No plugins, and the scope will do nothing.
The little green lights burn out all of the
time.

The manual tells you everything you need to
know about power supply diagnosis. It is
expecting that you will make DC measurements
with a DVM, and ripple measurements with another
scope, set to LINE trigger, and sweep at 5ms/div.

In this mode, ripple will be stationary.

The really high frequency glitches on the power
can be ignored, but the 60Hz and 120Hz ripple
are important, as are the general noise level.

The unregulated outputs are not critical as
to value, but do need to be close. They are
not especially critical as to ripple, expect
high values. Their purpose is to feed regulators.

They will vary greatly depending on your mains
voltage, and the mains setting of the scope.

The 7603 has a linear power supply. All of the
regulators are referenced to the -50V regulated
supply. You show it way off, everything else will
be off proportionately. Fix it first. Don't just
adjust it, fix it.

-Chuck Harris

Robert Hay wrote:
So far no plugins and the light isn't lit. I'll check it.

Bob.


On 9/8/2018 7:43 PM, Robert Hay wrote:
I have seen this Tek 7603 scope sitting on the table at the Tek Country store for
at least three years. I have tried to power it up and twist some knobs several
times over the years with no response. They have been asking $35 for it and I
noticed today there are about 5-6 price stickers stacked up under the current one.

I have been thinking a 7603 would fit into my ensemble if I clear space for it by
giving another scope to the Tek Museum. So, I asked if they would take $25 for it
and they did. So, here it sits with the covers off and the power supply hanging
out the back. It doesn't do nut-tin when powered up.

The main fuse, the fuse on the regulator board and the one on the power supply
board above the caps are good. I checked the power supply voltages on the regulator
board with the following results:

Volt VDC VAC
130 114 11
50 44 5
5 4.396 0.25
15 13.2 1.4
-15 -13.17 1.3
-50 -44 4.8

Unregulated Voltages

50 66 0.16
-50 -52 13
15 24 0.04
-15 -24 0.1
5 12.4 0.05

Seems to be discrepancies between the ripple on the corresponding regulated and
unregulated supplies which I don't understand.

The 130 volt supply is partly made up from the 50 volt supply and the voltage on
the emitter of Q850 should add about 40 volts but I measure 10.8 volts DC there.
Maybe I see it now, if the 50v supply is at 44 volts there is no way the emitter of
Q850 can get to 40 v.

I appreciate any ideas from folks especially those who have been thru a 7603
before. Haven't had a chance to research the archive but will do that before doing
more troubleshooting. I can't take another scope to the Tek Museum until I know we
can bring this one back to service.

Bob.







Re: Tek 7603 Followed Me Home

John Griessen
 

On 9/9/18 10:11 AM, Robert Hay wrote:
I'll re-check the voltages
50 and -50 being actual 44 and -44 is the big clue.

Chuck was saying you probably have a very much changed component contributing
the the +44 and -44 regulated voltages, so some individual component volt level measurements are next to do.

Them both being the same 44V suggests some protection feature of the circuit is kicking in because some
filter caps are too leaky, but not shorted or open yet.
Look for bad caps there after the regulator.

The -52 for unregulated 50 is not likely enough headroom to regulate to 50V, so that is suspect also.
Look for bad caps there before the regulator.

7S12 Extender.

William Himbert
 

Hello Everyone:

I've recently purchased a nice 7S12 (with S-52 and S-6) from a seller, which worked fine when he had it but somehow in shipping (or slightly thereafter when I powered it up in my 7904) has acquired a strange problem affecting both the horizontal and vertical deflection. Is there anybody out there that would be able to sell or loan me a 7S12 internal card extender to assist in the diagnosis work when I am ready to get started? (I have to exhaust some basic testing first, along with building another mainframe extender as I only have one now.)

I searched the group for this kind of problem, and I only found one reference to someone who had a problem with both the horizontal and vertical deflection, but nobody responded to their call for help. Interestingly, the front panel SWEEP OUT seems to have a proper ramp (0-10V) and the horizontal card test points look like the right wave-forms according to the service manual, but on the scope screen I can only get 4 divisions of display maximum. All other plug-ins work in the same slots with no problem. At one point I improved the vertical a bit by re-seating all of the components on the vertical board, but then later while diagnosing the horizontal problem I lost most of the vertical deflection again, and the DC OFFSET no longer re-positions the beam up and down. Very odd!

Originally I was thinking that the only thing that could affect both the H and V deflection would be a power rail, but this seems unlikely so far as all of the internal voltages seem ok.

Regards,
Bill

Re: Tek 7603 Followed Me Home

Chuck Harris
 

My guess would be the -50V unregulated supply's
filter capacitor is no longer any good.

His VAC readings are certainly Vrms as read by his
DVM, so they are 2 x 1.4Vp-p, or in other words, he
has: 13Vrms x 2.8Vp-p/Vrms, or 36Vp-p ripple on a 50V
unregulated supply. No way that can work!

-Chuck Harris

John Griessen wrote:

On 9/9/18 10:11 AM, Robert Hay wrote:
I'll re-check the voltages
50 and -50 being actual 44 and -44 is the big clue.

Chuck was saying you probably have a very much changed component contributing
the the +44 and -44 regulated voltages, so some individual component volt level
measurements are next to do.

Them both being the same 44V suggests some protection feature of the circuit is
kicking in because some
filter caps are too leaky, but not shorted or open yet.
Look for bad caps there after the regulator.

The -52 for unregulated 50 is not likely enough headroom to regulate to 50V, so that
is suspect also.
Look for bad caps there before the regulator.



Re: 7S12 Extender.

Craig Sawyers <c.sawyers@...>
 

I've recently purchased a nice 7S12 (with S-52 and S-6) from a seller, which worked fine when he had
it
but somehow in shipping (or slightly thereafter when I powered it up in my 7904) has acquired a
strange problem affecting both the horizontal and vertical deflection. Is there anybody out there
that
would be able to sell or loan me a 7S12 internal card extender to assist in the diagnosis work when
I am
ready to get started? (I have to exhaust some basic testing first, along with building another
mainframe extender as I only have one now.)
I think you need to tell people where on the planet you are.

Craig

Re: Tek 7603 Followed Me Home

John Griessen
 

On 9/9/18 11:57 AM, Chuck Harris wrote:
His VAC readings are certainly Vrms as read by his
DVM, so they are 2 x 1.4Vp-p, or in other words, he
has: 13Vrms x 2.8Vp-p/Vrms, or 36Vp-p ripple on a 50V
unregulated supply. No way that can work!
Oh, yeah, missed that DVM VAC reading. Must be a little air capacitance in a dried out can!
Really suggests caps needing replacing.

Re: 7S12 Extender.

Dave Daniel
 

Somewhere I have an extender for these plug-ins. I forget the part number for the extender . I’d be happy to loan it to you if I can find it; I just moved from Colorado back to Florida and haven’t unpacked everything yet.

DaveD

Sent from a small flat thingy

On Sep 9, 2018, at 12:49, William Himbert via Groups.Io <wah_1003=yahoo.com@groups.io> wrote:

Hello Everyone:

I've recently purchased a nice 7S12 (with S-52 and S-6) from a seller, which worked fine when he had it but somehow in shipping (or slightly thereafter when I powered it up in my 7904) has acquired a strange problem affecting both the horizontal and vertical deflection. Is there anybody out there that would be able to sell or loan me a 7S12 internal card extender to assist in the diagnosis work when I am ready to get started? (I have to exhaust some basic testing first, along with building another mainframe extender as I only have one now.)

I searched the group for this kind of problem, and I only found one reference to someone who had a problem with both the horizontal and vertical deflection, but nobody responded to their call for help. Interestingly, the front panel SWEEP OUT seems to have a proper ramp (0-10V) and the horizontal card test points look like the right wave-forms according to the service manual, but on the scope screen I can only get 4 divisions of display maximum. All other plug-ins work in the same slots with no problem. At one point I improved the vertical a bit by re-seating all of the components on the vertical board, but then later while diagnosing the horizontal problem I lost most of the vertical deflection again, and the DC OFFSET no longer re-positions the beam up and down. Very odd!

Originally I was thinking that the only thing that could affect both the H and V deflection would be a power rail, but this seems unlikely so far as all of the internal voltages seem ok.

Regards,
Bill


514AD in Dayton, Ohio

Kurt Rosenfeld
 

wtb - Tek R7603 in Canada

Lawrence Glaister
 

I would like to buy a standard model 7603 or preferably an R7603 (rack mount model). Shipping these is not a pleasant experience, but might be possible if I can locate one on this side of the border. I am located on Vancouver Island (western Canada). Anyone trying to relocate stuff to a good home?

cheers
Lawrence VE7IT
Nanoose Bay BC

Re: 7S12 Extender.

William Himbert
 

I am in Eastern Pennsylvania. I can send my address off group.

Re: 067-0587-01 Calibrator Fixture

Tomas Alori
 
Edited

I dont have another mainframe but I tried the calibrator on the horizontal slots with a timebase on the vertical slots and I dont see the decrease in separation when I increase the repetition rate. So it seems that the problem is somewhere in the vertical circuitry of the mainframe.

I cant see how this could be a bandwidth problem since I calculated a bandwidth of around 280Mhz on both vertical slots when using the pulse/risetime function. Also the gain function is pretty low frequency with a 1Mhz repetition rate. So it doesnt seem to be a bandwidth problem as far as I know. I guess it could be more of a frequency response problem?

I forgot to try your first suggestion (watching for changes in the observable rise time). I will try soon, but hopefully the information in this post can help. Thanks.

Re: 7K series - Conceptual question - what is the _least_ useful 7000 plugin?

ditter2
 

I assume you are talking about today's market, where these are available surplus, many at a fraction of the original price.

In this case I would say the single channel amplifiers, such as the 7A16. Why give up a full slot for a single channel, when a 7A26 gives two channels at the same performance.

- Steve

Re: Welcome to TekScopes@groups.io

Jeff Pederson
 

Tek 475 proper operation (detailed) of freq select switches A-B delayed.
I have to repair the "music box" sweep selector switch, and align the cam stop on the back half. As near as I can tell, the cam stop prevents the b delayed, from being pulled out at some point for 2 or 3 positions. I can only assume it is at the last 2 positions at the far right.
I purchased this unit not working, and someone was into it before me.
Thanks in advance.

On Friday, September 7, 2018, 9:04:12 PM PDT, TekScopes@groups.io Group Moderators <TekScopes+owner@groups.io> wrote:


Hello,

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The TekScopes@groups.io Moderator

telequipment s54a trace too low on y

james.simpson54@frontier.com
 

This is my post on another forum, this forum popped up when I googled a different search term. I'm hoping someone here may know what the exact problem is.
I have a s54a and it was working properly when I used it about a year (?) ago, but today when I tried to use it the waveform is way to "low" in the y positioning on the screen The only way i can get it to center is to turn the voltage variable knob to the extreme counter clockwise (to be properly calibrated this knob is supposed to be fully clockwise) and then turning the y positioning knob and vernier knob to their extremes, but with the voltage variable knob now being NOT in it's calibration position the waveform voltage measurement is not accurate. I have the manual for it but I can't find anything about an adjustment for the y position other than the knobs on the front panel. I was wondering if anyone knows if there is an adjustment inside the unit for the y positioning and also wondering if anyone knows of an actual service manual for the unit? I'm kind of thinking many of the S series of scopes may have the same y positioning adjustment somewhere inside the unit. I like using it even though I don't use it much. I wanted to use it today to calibrate my super cricket transistor checker but because of that y positioning problem I had to use a different scope. On the plus side the super cricket was pretty much spot on, there was another calibration on it using a amp meter and then making adjustments to put the needle at the proper number and that was pretty close also, but I really prefer using the telequipment scope. Thanks in advance.
On the other forum it has been suggested not to seek an adjustment but a bad component, but I was thinking if ,say a capacitor, has drifted some in value that making an adjustment to compensate for it would be ok, but I'm not sure about that. I have no experience repairing scopes and I really need a service manual that gives pretty good instructions and troubleshooting tips to make a repair of something like an old radio shack shortwave receiver, for an example.I have the manual for this scope , which I believe they call an instruction/service manual but it doesn't really go into troubleshooting.

Re: TDS210, schematic and parts required.

Graham Butcher
 

Dave, while the points you raise may or may not be justified with regard to the releasing of schematics and detailed service manuals etc, the fact still remains that somewhere along the line these were produced and yes, I can accept that they were probably in PDF format, for their own internal and external appointed service engineers. Therefore it is not difficult for these to be made available online for subsequent downloading by anyone requiring them, especially once the product reaches the end of its production run which the TDS210 series had done many years ago.

What these large corporations need to understand is that from today's hobbyists, there are going to be a large number of tomorrows decision makers in other large corporations and their experiences today, will almost certainly colour their decisions when they have to decide whether they commit their corporations to buying large quantities of brand X or Y at the next upgrade to their equipment.

If brand X has the air of arrogance about them and is not forthcoming in customer support but brand Y does, its clear where that person's decision is going to be skewed towards is it?

Graham
________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Artekmedia <manuals@...>
Sent: 07 September 2018 19:49
To: TekScopes@groups.io
Subject: Re: [TekScopes] TDS210, schematic and parts required.

Graham et all

While I appreciate the frustration at no longer being able to get
schematics for the newer gear don't flatter yourself that as "hobbiest"
that any large equipment corporation really cares whether you buy a new
piece of gear or not. You (and I) as hobbiest living off the dumpster
dregs are such a small portion of the total market as to not be
relevant. The evolution of the loss of schematics in newer gear/manuals
was an evolutionary process, driven by many factors;

1) The "real" cost of printing a new service manual is much higher than
you might expect and goes way beyond the hourly cost of the copy and
printing room hourly employee. By the time you figure the buyers time to
buy supplies, inventory carrying cost, overhead costs (FICA Taxes,
health insurance, 401K contribution, vacation, sick leave, a piece of
the copy room persons boss, and his boss and his bosses boss, HR
person,etc ) the activity based costs for a 300 page page service manual
can easily go beyond $250-$500 per copy. At $300 you would unlikely be
willing to pay for a service manual for your TDS210 even if I could show
you that is what it costs to produce it in today's dollars This is a
very big reason why we don't at ArtekManuals produce hard copies of
manuals we already have scanned, most people will live with a PDF for
$15 before they will pay even a $100 for a good paper copy. The
economics of this is why a large percentage of the guys who were
printing xerox copies 5 years ago (Manuals Plus, Your Manual Source,
Etc) have hung up their aprons, they could make enough margin to cover
the OH costs of just the warehouse alone let alone "production costs.

2) Next with the influx of custom IC's, 256pin gull wing packages and
finally ball grid arrays the ability to repair a modern board goes
beyond the talent of most all but a few of we mere mortals with our
weller solder guns.

3) Then there was the case for protecting intellectual property. While
not as big a factor in today's world, reverse engineering back in the
90's when this trend started was certainly aided by the full schematics.

You couple all of the above together plus a few more things and everyone
in the meeting room where this was being discussed 30 years ago slammed
their palm against the foreheads, muttered "duhhhh" under their breath
and agreed to get out of the manual business.

Tried to work on your own car lately???? A dont forget to stop off on
the way home from work tonight and buy the guy who runs the local TV
repair shop a beer ...Oh wait you stopped taking your TV to the shop 30
years ago too and he went out of business

Flame suit on :-P

Dave
manuals@...

On 9/7/2018 2:06 PM, Graham Butcher wrote:
Oh, so they are doing an "Apple" on us then eh, denying us the right to repair our own property, I can understand it if its within warranty but once its no longer covered by warranty then we should have the right to be able to repair ourselves or take to someone who can repair it paying through the nose for it. Not only that but these things are now 30 years old and they don't to repair them, they want us to buy a new model from them, grrr

Graham
________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of David Kuhn <Daveyk021@...>
Sent: 07 September 2018 14:01
To: TekScopes@groups.io
Subject: Re: [TekScopes] TDS210, schematic and parts required.

No schematics because Tek wants all the service business for themselves,
and like Germans, think that no one in the world is smart enough to
understand their designs in order to service them themselves.

One Tek, or other manufacturers, stop service repair support for a product,
they should release the schematics.

I would love to have the schematics for a Agilent 11723B. They were almost
going to send me copies with an NDA, but at last minute said they would
evaluate it for only $300. Then they would decide witch board to replace.
(Sigh)

Dave

On Thu, Sep 6, 2018 at 1:12 PM Graham Butcher <
graham.l.n.butcher@...> wrote:

Yes I did try there and thats where I downloaded the user and service
manuals but it has no schematics (in fact it has a request just below the
tag for the manuals requesting schematics to be uploaded) It also of course
does not provide any linkage or reference to spare parts unless I missed
something?

Graham







--
Dave
Manuals@...
www.ArtekManuals.com<http://www.ArtekManuals.com>

Re: 310A scope : serial number oddity ? Ideas ?

ditter2
 

As for the BNC versus UHF connectors on your unit, they may have been upgraded. Tek offered a mod kit for several of the tub instruments to convert to BNC connectors. You can probably get a good idea of the manufacturing date by looking at the date codes of the large electrolytic caps. Most have a date code of the form xx-yy or xxyy, where xx is the week of the year, and yy is the last two digits of the year. As this was a rather high volume production model, it is reasonable to assume that the scope was manufactured with 2-4 months from the component date codes.

Many tubes also have date codes. Of course some may have been replaced, but quite often the majority of tubes in these old instruments are the original. To be sure, check several tubes and see if the date codes are the same or within a couple of weeks of each other.

- Steve

Re: TDS210, schematic and parts required.

Harvey White
 

On Mon, 10 Sep 2018 00:47:49 +0000, you wrote:

Dave, while the points you raise may or may not be justified with regard to the releasing of schematics and detailed service manuals etc, the fact still remains that somewhere along the line these were produced and yes, I can accept that they were probably in PDF format, for their own internal and external appointed service engineers. Therefore it is not difficult for these to be made available online for subsequent downloading by anyone requiring them, especially once the product reaches the end of its production run which the TDS210 series had done many years ago.
True enough. When out of service life, it's not going to be
reasonable that Tek will service it.

And that's not a problem.

You're expected to toss it, and go buy another, better, far more
expensive model. You're a big company with a multi-million dollar
test equipment budget.



What these large corporations need to understand is that from today's hobbyists, there are going to be a large number of tomorrows decision makers in other large corporations and their experiences today, will almost certainly colour their decisions when they have to decide whether they commit their corporations to buying large quantities of brand X or Y at the next upgrade to their equipment.
That actually is likely not a concern to the people making the
decisions. The likely scenario is this:

You're a big company, your jobs are determined by this quarter's
profits, not next years, not five years from now.

You are a new engineer/hobbiest. You don't get a say in who buys
what, you're too junior a member. If you do have a say, then it's
likely your a startup with not enough money to be important.

You're an older engineer where someone might pay attention to you,
somewhat. You specify a piece of equipment. Purchasing says it's too
expensive and rejects it, or finds another with "equivalent" specs. If
you do get your purchase approved, then good for you.

You're a hobbiest: You don't have any money. You're not going to buy
a 7000 dollar tektronix scope that performs only slightly better than
what you could buy for one tenth the cost.

Add in the difficulty of repairing a scope that is three boards (one
power supply) has all BGA chips that are all custom which need some
rather interesting equipment to replace even IF you can find the
chips, well.

We don't need clips to repair the equipment, all we do is either
return it, or swap boards with the manufacturer.

There's a generation of corporate types for whom loyalty is buying the
latest one in 30 days, further out than that is not important.

Perhaps this is a bit too cynical, for which, I would most happily be
proven wrong...

Note now that I'm talking the behavior of corporations, and not
individuals.

The TDS series has/had somewhat of a lack of data available, so you
have to be creative and hope that it works (yes, I have one that isn't
working).

Harvey




If brand X has the air of arrogance about them and is not forthcoming in customer support but brand Y does, its clear where that person's decision is going to be skewed towards is it?

Graham
________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Artekmedia <manuals@...>
Sent: 07 September 2018 19:49
To: TekScopes@groups.io
Subject: Re: [TekScopes] TDS210, schematic and parts required.

Graham et all

While I appreciate the frustration at no longer being able to get
schematics for the newer gear don't flatter yourself that as "hobbiest"
that any large equipment corporation really cares whether you buy a new
piece of gear or not. You (and I) as hobbiest living off the dumpster
dregs are such a small portion of the total market as to not be
relevant. The evolution of the loss of schematics in newer gear/manuals
was an evolutionary process, driven by many factors;

1) The "real" cost of printing a new service manual is much higher than
you might expect and goes way beyond the hourly cost of the copy and
printing room hourly employee. By the time you figure the buyers time to
buy supplies, inventory carrying cost, overhead costs (FICA Taxes,
health insurance, 401K contribution, vacation, sick leave, a piece of
the copy room persons boss, and his boss and his bosses boss, HR
person,etc ) the activity based costs for a 300 page page service manual
can easily go beyond $250-$500 per copy. At $300 you would unlikely be
willing to pay for a service manual for your TDS210 even if I could show
you that is what it costs to produce it in today's dollars This is a
very big reason why we don't at ArtekManuals produce hard copies of
manuals we already have scanned, most people will live with a PDF for
$15 before they will pay even a $100 for a good paper copy. The
economics of this is why a large percentage of the guys who were
printing xerox copies 5 years ago (Manuals Plus, Your Manual Source,
Etc) have hung up their aprons, they could make enough margin to cover
the OH costs of just the warehouse alone let alone "production costs.

2) Next with the influx of custom IC's, 256pin gull wing packages and
finally ball grid arrays the ability to repair a modern board goes
beyond the talent of most all but a few of we mere mortals with our
weller solder guns.

3) Then there was the case for protecting intellectual property. While
not as big a factor in today's world, reverse engineering back in the
90's when this trend started was certainly aided by the full schematics.

You couple all of the above together plus a few more things and everyone
in the meeting room where this was being discussed 30 years ago slammed
their palm against the foreheads, muttered "duhhhh" under their breath
and agreed to get out of the manual business.

Tried to work on your own car lately???? A dont forget to stop off on
the way home from work tonight and buy the guy who runs the local TV
repair shop a beer ...Oh wait you stopped taking your TV to the shop 30
years ago too and he went out of business

Flame suit on :-P

Dave
manuals@...

On 9/7/2018 2:06 PM, Graham Butcher wrote:
Oh, so they are doing an "Apple" on us then eh, denying us the right to repair our own property, I can understand it if its within warranty but once its no longer covered by warranty then we should have the right to be able to repair ourselves or take to someone who can repair it paying through the nose for it. Not only that but these things are now 30 years old and they don't to repair them, they want us to buy a new model from them, grrr

Graham
________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of David Kuhn <Daveyk021@...>
Sent: 07 September 2018 14:01
To: TekScopes@groups.io
Subject: Re: [TekScopes] TDS210, schematic and parts required.

No schematics because Tek wants all the service business for themselves,
and like Germans, think that no one in the world is smart enough to
understand their designs in order to service them themselves.

One Tek, or other manufacturers, stop service repair support for a product,
they should release the schematics.

I would love to have the schematics for a Agilent 11723B. They were almost
going to send me copies with an NDA, but at last minute said they would
evaluate it for only $300. Then they would decide witch board to replace.
(Sigh)

Dave

On Thu, Sep 6, 2018 at 1:12 PM Graham Butcher <
graham.l.n.butcher@...> wrote:

Yes I did try there and thats where I downloaded the user and service
manuals but it has no schematics (in fact it has a request just below the
tag for the manuals requesting schematics to be uploaded) It also of course
does not provide any linkage or reference to spare parts unless I missed
something?

Graham







Re: telequipment s54a trace too low on y

Harvey White
 

On Sun, 09 Sep 2018 13:38:33 -0700, you wrote:

This is my post on another forum, this forum popped up when I googled a different search term. I'm hoping someone here may know what the exact problem is.
I have a s54a and it was working properly when I used it about a year (?) ago, but today when I tried to use it the waveform is way to "low" in the y positioning on the screen The only way i can get it to center is to turn the voltage variable knob to the extreme counter clockwise (to be properly calibrated this knob is supposed to be fully clockwise) and then turning the y positioning knob and vernier knob to their extremes, but with the voltage variable knob now being NOT in it's calibration position the waveform voltage measurement is not accurate. I have the manual for it but I can't find anything about an adjustment for the y position other than the knobs on the front panel. I was wondering if anyone knows if there is an adjustment inside the unit for the y positioning and also wondering if anyone knows of an actual service manual for the unit? I'm kind of thinking many of the S series of scopes may have the same y positioning adjustment somewhere inside the unit. I like using
it even though I don't use it much. I wanted to use it today to calibrate my super cricket transistor checker but because of that y positioning problem I had to use a different scope. On the plus side the super cricket was pretty much spot on, there was another calibration on it using a amp meter and then making adjustments to put the needle at the proper number and that was pretty close also, but I really prefer using the telequipment scope. Thanks in advance.
There are adjustments that keep the trace from moving when the gain
control is changed. However, the amplifier is a balanced amplifier
(generally) so look at the schematic and see if there's a + and -
drive. The voltage on each plate of each tube ought to be the same
when the trace is centered. What you're looking for is an inbalance
between the + drive and the - drive to the plates, where ever it comes
in.

First thing is to either swap tubes + to - in the channel and see if
that changes things. Testing tubes is also a good idea if you can.

It's possible that a coupling or decoupling capacitor can be bad, but
since this is a DC coupled scope, there aren't any decoupling
capacitors, so look for bypass capacitors or weak tubes.

NOTE: mark the tubes and where they are so you can put them back in
the original places as needed. For the sake of your own sanity, swap
only two at a time, then put them back. (don't ask).


Harvey


On the other forum it has been suggested not to seek an adjustment but a bad component, but I was thinking if ,say a capacitor, has drifted some in value that making an adjustment to compensate for it would be ok, but I'm not sure about that. I have no experience repairing scopes and I really need a service manual that gives pretty good instructions and troubleshooting tips to make a repair of something like an old radio shack shortwave receiver, for an example.I have the manual for this scope , which I believe they call an instruction/service manual but it doesn't really go into troubleshooting.