Date   
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:


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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.


Re: TDS210, schematic and parts required.

Graham Butcher
 

Maybe I'm not explaining myself fully here, but I doubt that many large corporations will be bothered about getting the equipment serviced, far quicker to buy a new one so the analogy of corporations seeking to get access the the schematics is not one that I was portraying or could envisage happening.

None of those examples remove the need for the lifting of releasing the required information once a product ceases production, many companies actually pride themselves on having archives of data on their older products and many of us of made use of them in the past and I seriously doubt if their decision to play fair with hobbyists etc has had any negative impact on their company wellbeing .

Students and young hobbyists have limited resources and so information is vital to them and it is these very people who could be in the large corporations in a few years time, making the decision of which to buy and any such corporation that then allows purchasing to for the cheapest option is doing themselves a great disservice as buyers will not be aware of the reasons why the person requested xyz and in many cases will have zero knowledge pf the product and its use anyway and by replacing it with a cheap abc could well backfire on them big time when abc cannot do what xyz could and that was one of the reasons they requested in the 1st instance.

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

Gary Robert Bosworth
 

There was a plug-in for the 7104 1GHz scope. I can't remember the model
number right now, but I own one. It was single channel and drove the
vertical plates directly to give the fastest possible response. It was not
widely publicized that you had to make several very complex modifications
inside the oscilloscope for the plug-in to function at all. Needless to
say, it was a waste of my money.

On Sun, Sep 9, 2018 at 5:40 PM ditter2 via Groups.Io <ditter2=
yahoo.com@groups.io> wrote:

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



--
Gary Robert Bosworth
@grbosworth
Tel: 310-317-2247

Re: Tek 7603 Followed Me Home

bobh@joba.com
 

Yup, DMM916 meter readings.  My day was spent taking out of town guests up the Columbia Gorge.  Will try to dig further into it tomorrow.  Seems like the load from the plugins help stabilize some of the voltages but the -50 is not right.

Bob.

On 9/9/2018 9:57 AM, Chuck Harris wrote:
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: telequipment s54a trace too low on y

james.simpson54@frontier.com
 

It's a solid state scope. I just uploaded the manual to the files section. It is titled s54aoscilloscope that has the schematics for the unit. I was hoping someone may have already done a repir on this or a similar unit

Re: Bringing up a Tek 555 dual-beam scope

ditter2
 

I have restored over two dozen 500 series tube scopes, both plug-in and monolithic, including one 555.
My technique differs from Rajesh's quite a bit. I have a variac, but usually do not use it, rather, I just plug it in and flip the power switch. The variac is of limited use with the models which include the time delay for the plate supplies, which include the 555. Other than the power supply, the rest of the scope will get hit with the full voltages when the relay clicks.

I am not a big fan of blindly recaping instruments. Anytime you touch a soldering iron to one of these old beauties, you risk damaging something. Almost always the insulation on the wire retracts, exposing more bare wire. Of these many scopes I have restored, I have only had to replace an electrolytic on two of them (also had this in one "modern" scope - 5103).

Testing the HV electrolytic caps with a C meter is in accurate due to the low voltage. The values will generally read much lower when excited with a few volts. Also, measuring ESR is questionable, because it is difficult to know what the values should be in these old caps. The best way to assert the performance of these old caps is to measure the peak to peak ripple and the ripple valley, using a differential amplifier with an offset mode (7A13 or type W). As long as you more voltage in the valley than the saturation voltage of the regulator tube, the cap is doing its job. (you may want to make these tests with a variac set to the low line voltage for the transformer tap you are using.)

True, the "bumble bee" caps in the signal path will likely be bad and need replaced, but there is no danger in turning on the scope with these in the scope if they are bad, and troubleshooting to find them is usually fairly easy.

I do remove the covers before I power up to scope the first time to check for smoke. If you see smoke, resist the urge to immediately turn off the power. The larger carbon comp resistors need several seconds of giving off smoke before they burn or even discolor. But the value may change considerably when they over heat. I had this happen a couple of times, and found it very difficult to find the specific resistor to troubleshoot because I did not let it burn long enough.

I do wash all my scopes that i restore, but I don't wash them before initial power unless they are very dirty - layers of dust. But I do clean the CRT HV circuits - usually with compressed air.

Do check the fan mechanically to be sure the bearings allow it to turn freely, the blades clear, and for models that use them, the rubber shock mounts are still intact. Often they are not. You can find a direct replacement for these from McMaster-Carr.

I always turn the focus knob to the stop and intensity down before initial power up. I have had a few scopes with problems in the CRT grid circuit that resulted in high beam current even with the intensity turned down, and if the CRT was focused, the phosphor would likely be burned.

Shorted tubes will damage the scope, but they are rare. If you do remove tubes to test them, do so one at a time or keep track of the location each came from. It is not a good idea to swap tube locations, although they are the same type. Many of the adjustments in the scope account for differences in tube operation, so swapping them will likely put more of the circuits out of adjustment.. But you may want to verify the tubes are in the correct locations. I only had this happen once with a type CA plug-in. Someone had removed all the tubes and put them back in, but only matching the lead count (7 or 9 pin) and not that the correct tube type is in the correct location. Quite a bit of damage was done to the plug-in and even one of the power supplies in the test scope when I powered it up.

- Steve

Re: 7K series - Conceptual question - What's the 3rd most useful plugin

 

Hi Scott,

I have to disagree about the 7M13. It is nowhere near the bottom of my list.
I use the 7M13 frequently. It is very useful, particularly in a 4 slot
scope, for documenting odd test conditions for future reference when I take
scope pictures (which I do very often).

I am aware that I am probably an exception when it comes to the kinds of
things I measure and document. With my extensive collection of plugins some
of my "fun" comes from taking advantage of every instrument and plugin Tek
has given us.

The 7M11 is one I use very little but I have used it on occasion. In my
opinion its biggest drawback is the 175pS risetime. I wish there was an
equivalent with risetime faster than the S-6 (<= 30pS) and S-4 (<=25pS)
sampling heads. Then it would be handy for delaying signals so the 7T11
could trigger on them in sequential mode.

The 7A17 is still at the bottom of my list since I haven't found any use for
it so far in spite of it offering a very easy way to connect a signal to a
7K mainframe. I bought a 7A17 in 1977 when I bought my 7704A / 7A26 / 7B80 /
7B85 so I could use it as an inexpensive 3rd channel and fill what would
otherwise be an empty slot.

Over the years some possible ideas I toyed with for the 7A17 were as:

* A 2 channel multiplier. I later discovered that the 7A26 is a better
candidate as a 2 channel multiplier since both channels are already in the
plugin with all the attenuators and support circuitry. It might be as simple
as connecting the two output channels through an analog multiplier IC just
before they reach toe back connector.

* A logarithmic amplifier. When I started working with spectrum analyzers I
learned they already display spectral energy on a log scale and I lost
interest in that idea.

* A constant amplitude amplifier. The constant amplitude idea came out of
the annoyance of constantly adjusting the volts/div knob to keep a trace on
the screen in some measurement situations. It would work like an automatic
volume control does to hold the amplitude constant. You could choose an
incoming signal to occupy 1, 2, 3...7 or 8 divisions with a simple 8
position rotary switch. As the signal amplitude changed the amplitude on the
screen would remain constant but the readout would update to show how many
volts/div each division represented (within a few percent). I think this
idea is quite possible. Steve Ditter pointed out a combination DVM and
on-screen readout IC that Tek makes that should be able to display volts/Div
on the screen with an accuracy of a few percent. Thanks to Steve I was able
to buy a couple of these off Ebay at bargain prices a few years ago.

Dennis Tillman W7PF

-----Original Message-----
From: Scott McGrath
Sent: Saturday, September 08, 2018 6:38 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7K series - Conceptual question - What's the 3rd
most useful plugin

I think the vote for least useful plug in needs to be for the 7M13, which
allowed you to place text on the screen.

The 7M11 - may be a close second as its a dual 75 ns delay line which uses
the scope only for power

Content by Scott
Typos by Siri



--
Dennis Tillman W7PF
TekScopes Moderator

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

 

Hi Gary,

I replied about this plugin you are referring to the other day. Here again are my relevant comments:

-----Original Message-----
From: Dennis Tillman W7PF
Sent: Friday, September 07, 2018 8:22 PM
Subject: Re: [TekScopes] 7K series - Conceptual question - What's the 3rd most useful plugin

<snip>

The 7A21N would be a close tie for the 7A17. It was in the catalogs from
1972 until 1979. It was used with the 500MHz 7904 when the 7904 was the fastest 7000 scope. It boosted the bandwidth to over 1GHz by going direct to the 8cm x 10 cm CRT's deflection plates. The combined sensitivity was 4V/Div or 2V/Div differential. It was the only way to get to 1GHz until 1979 other than the 519. It sure was a lot better than a 519 (10V/cm) with a tiny 2cm x 6cm screen. I did use the 7A21N for several weeks more as an experiment than anything else. When the 7104 was introduced in 1979 it made the 7A21 obsolete.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Gary
Robert Bosworth
Sent: Sunday, September 09, 2018 7:31 PM
To: TekScopes@groups io <TekScopes@groups.io>
Subject: Re: [TekScopes] 7K series - Conceptual question - what is the
_least_ useful 7000 plugin?

There was a plug-in for the 7104 1GHz scope. I can't remember the model
number right now, but I own one. It was single channel and drove the
vertical plates directly to give the fastest possible response. It was
not widely publicized that you had to make several very complex
modifications inside the oscilloscope for the plug-in to function at all.
Needless to say, it was a waste of my money.

--
Gary Robert Bosworth
@grbosworth
Tel: 310-317-2247



--
Dennis Tillman W7PF
TekScopes Moderator

Re: telequipment s54a trace too low on y

jim <ab7vf@...>
 

I've got a D54 played with it loooong ago ..But First track down and measure the power supply voltages ..There are no special (or any at all) voltage regulator circuits , Just R's and C's Y amp has 75v supply and 16v supply ...If you don't want to clutter up the list, ab7vf at yahoo (dawt) com will work

Jim

On Sunday, September 9, 2018, 7:48:26 PM PDT, james.simpson54@... <james.simpson54@...> wrote:

It's a solid state scope. I just uploaded the manual to the files section. It is titled s54aoscilloscope that has the schematics for the unit. I was hoping someone may have already done a repir on this or a similar unit

Re: telequipment s54a trace too low on y

james.simpson54@frontier.com
 

Thanks. Exactly the type of instruction I need to get started. Unfortunately,when changing tires on my car yesterday I discovered a broken sway bar link. I was going to take it in but I'm unemployed so I figured I'll do it myself. So I have to get that taken care of and then break that scope out again. Thanks again.

Re: Bringing up a Tek 555 dual-beam scope

Dave Wise
 

I agree except to emphasize that plastic-enclosed oiled paper (e.g. "Black Beauty" aka "bumblebee") are always bad and should be replaced. There are several in the Holdoff circuit which slow or prevent sweep, and several in the power supplies which cause sub-normal voltage. Also some in the HV section, one of which will prevent the oscillator from starting.

Another thing to watch for is silver migration on the ceramic terminal strips. Adjacent terminals with a lot of potential difference will migrate and eventually flash over which can ruin the strip. Keep 'em clean.

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of ditter2 via Groups.Io <ditter2=yahoo.com@groups.io>
Sent: Sunday, September 09, 2018 8:20 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Bringing up a Tek 555 dual-beam scope

I have restored over two dozen 500 series tube scopes, both plug-in and monolithic, including one 555.
My technique differs from Rajesh's quite a bit. I have a variac, but usually do not use it, rather, I just plug it

<big snip>

Re: 7K series - Conceptual question - What's the 3rd most useful plugin

fiftythreebuick
 

Scott, I would disagree on the 7M13...

If you need to add a bit of documentation to a scope photo for inclusion in a report or for archival purposes, the 7M13 is absolutely great! I have a couple of them and have used them a lot.

Tom

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

Vincent Trouilliez
 

On Sun, Sep 9, 2018 at 05:51 PM, ditter2 wrote:
[..] 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.
[..] Many tubes also have date codes.

- Steve
Hi Steve,

I didn't want to open up the scope, as I have already a couple scopes I am working on at the moment, spread all over the bench... I wanted to keep the surprise of the 310A for later, when I actually have time to work on it. But.... it would be rude not to reply to you, and it gives me a good excuse to open it up sooner than I planned, so thank you ! LOL ^^

I think the BNC was fitted at the factory... as my scope is a late model it appears, actually so late it might as well be early solid state ! LOL

I had no luck with the tubes... pulled a dozen of them, at random places, from various manufacturers (Brima, Toshiba, Mullard, General Electric), none of them had date codes ! Bummer. Looked at the "cans"... luckily all very easy to access. 5 of them. 4 had date codes on them, all consistent : one was marked "1366", and the others read, in clear, "March 1966". So, end of March 1966 it is !

I am still a bit perplex : how can such a late 310A, have a serial number as low as #1239 ?! Baffles me...

This first peek inside the scope gave me preview of what I can expect when I get round to restoring this puppy... mixed feelings ! :-/
Basically looks brand new inside, even found a couple rubber grommets whose rubber still looks and feels as good as new, still a deep shiny blakc, still supple, and I am not even kidding. How can rubber survive 50+ years this well, no idea. Zero dust, all ceramic strips, components and solder joints, all look sparkling new.

However the big downside is that there is a thin layer of some very fine "powder", must be some oxide, yellow-ish/green-ish in colour, covering just about every single screw, head, thread, electrolytic can backing plate, every pot and trimmer (some have their shaft seized !), as well as all the little "lugs" on the tube sockets, where the anti-vibration copper "clip"/retainer attaches to, whatever it's called.
Boy I will have some fun sorting all this out ! Hopefully there exists some chemical/product that can dissolve all that oxide efficiently/easily... then I will have to remove all the pots to dismantle/open them, to free the shafts and make sure the wipers in them are OK.

Lots of fun ahead ! .....

Kudos to the engineers who managed to cram so much stuff in so little space, it is EXTREMELY tight in there ! :-O
Kudos as well to all the little hands at the factory who were tasked with assembling these things ! They deserve a medal...




Vincent Trouilliez

Re: telequipment s54a trace too low on y

Jim Tibbits
 

well that was a bodge assuming the s54 and d54 had anything in common ...s54 appears to have 105v and 12.5v supplies on the vertical .

"Vertical Amplifier" section on page 8 has check and aligning proceedure

Jim