Date   

Re: A slightly sick SG505

 

Hi Eric,
I can't help you directly but you might be interested in a SG505 I inherited that is incomplete. It probably came from the Tek Country Store. I have no use for it but you might be able to use it as a "parts mule" or for locating the problem with your SG505 by substituting parts from this one.

It is missing the Output Level rotary switch, Source R switch, and Intermod Test Sig pushbutton. All of the other front panel pushbuttons and knobs are there including the Frequency dial and that very interesting pot it turns. All of the ICs, transistors, caps, transformers, fuses, and even a small lightbulb appear to be there.
There are two 1" high standoffs about 2/3 0f the way towards the back of the plugin that may have held a small PC board (just a guess). Whatever they were holding is gone.

If you are interested please contact me off list at dennis at ridesoft dot com.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Eric
Sent: Wednesday, January 29, 2020 7:03 PM
To: TekScopes@groups.io
Subject: [TekScopes] A slightly sick SG505

I am hoping the wonderful minds here can help me with a sick SG505. The main output is working and the distortion is good. They Sync output is not working correctly. I have checked U1300 and Q1300 and 1301 off the board and they seem to be behaving like they should. For U 1300 the resistance between pins 4 and 5 goes down when power is applied to pin 1 and 2 with a bench power supply. I can see signal at the base of Q1301 but the signal seems to die in the optoisolater probing 5 or 4 with a scope shows dc only. Q1301 and 1300 both pass a diode test off the board as transistors of their respective types. I suspect U1300 but what is odd it seemed to work off the board. Not sure what I am missing.





--
Dennis Tillman W7PF
TekScopes Moderator


Re: Did something happen to Yahoo Groups Today?

Mlynch001
 

On Wed, Jan 29, 2020 at 09:04 PM, Dennis Tillman W7PF wrote:


For what it's worth I am still the administrator of the Yahoo TekScopes
Group.
About 1 or 2 times a week I get a notice that someone wants to join the
Yahoo TekScopes group and I redirect them to us.

I also receive a notice whenever someone leaves the Yahoo TekScopes group.
Normally there are a few of them per week.
But yesterday I got 11 of them within 2 hours which is extremely unusual.

Is anyone aware of something that happened on Yahoo that would explain this?

Dennis Tillman W7PF
Dennis,

I have been getting some e-mail about Yahoo Groups deleting files and closing down recently. Perhaps this has prompted people to leave the Yahoo group? I suppose I get these messages because I am a member here?

Just a guess.

Michael

--
Michael Lynch
Dardanelle, AR


Did something happen to Yahoo Groups Today?

 

For what it's worth I am still the administrator of the Yahoo TekScopes
Group.
About 1 or 2 times a week I get a notice that someone wants to join the
Yahoo TekScopes group and I redirect them to us.

I also receive a notice whenever someone leaves the Yahoo TekScopes group.
Normally there are a few of them per week.
But yesterday I got 11 of them within 2 hours which is extremely unusual.

Is anyone aware of something that happened on Yahoo that would explain this?

Dennis Tillman W7PF


A slightly sick SG505

Eric
 

I am hoping the wonderful minds here can help me with a sick SG505. The main output is working and the distortion is good. They Sync output is not working correctly. I have checked U1300 and Q1300 and 1301 off the board and they seem to be behaving like they should. For U 1300 the resistance between pins 4 and 5 goes down when power is applied to pin 1 and 2 with a bench power supply. I can see signal at the base of Q1301 but the signal seems to die in the optoisolater probing 5 or 4 with a scope shows dc only. Q1301 and 1300 both pass a diode test off the board as transistors of their respective types. I suspect U1300 but what is odd it seemed to work off the board. Not sure what I am missing.


Re: Where have all the Schematics Gone?

Brad Thompson
 

Dave Brown wrote on 1/29/2020 8:36 PM:

One of those turned up on the local club trading table a year or so back- working order- dunno who took it but could ask around in case they found a manual.(assuming you still have it?- most unlikely I guess!)
73
Dave, ZL3FJ

Hello, Dave--
Thanks for thinking of me. The SWOB went to the Happy Recycling Ground some years ago. I
replaced all of the filter caps before then but it had many more problems.
BTW, that beast weighed approximately 100 pounds.

73--

Brad  AA1IP


Re: Where have all the Schematics Gone?

Glenn Little
 

I bought a number of 2 GHz amplifiers at a hamfest.
I called the customer service number for the company.
The person in customer service sent me the checkout info.
When that package arrived, I called back about schematics.
He said that they had none.
I asked if he wanted schematics and he replied to the affirmative.
It took about a month of on and off time to generate the schematics.
When I emailed them to him and called to see if he had received them, he asked what I intended to use the amplifier for.
I told him amateur radio.
He then told me what circuits to disable and how to disable them to eliminate the pre distortion.
He was really helpful just crippled by lack of documentation.

Glenn

On 1/29/2020 6:26 PM, KeepIt SimpleStupid via Groups.Io wrote:
I called tech support for a Nuvo NV-MI1 mute interface for a doorbell and phone  https://www.legrand.us/nuvo/audio-video/brackets-accessories/accessories/mi1.aspx

I asked how it worked and what the output was.
The tech support guy was flabbergasted that he had no information on the device.In fact, he even asked me if they made it.


On Wednesday, January 29, 2020, 3:09:32 PM EST, David Kuhn <daveyk021@...> wrote:
I agree. At GE Inspection Technologies, the same thing happened after GE
purchased us.  Even our Sales Representatives with their own authorized
service departments could not get schematics.  Then the factory repair
service became a profit center and part prices went through the roof.
Well, GEIT is not more.  What is left of the company is a shell of itself.
The US Plant in Pennsylvania shut down, production moved between Southern
Ireland and Slovakia.  Service, without the experienced techs to the
Houston, TX area.  Now their name changed (GEIT is no more) and their
product offering a ghost of what it used to be.  Meanwhile, their
competitors are going great guns.

As far as Chinese Scopes. Siglent is quite good.  Even their 200MHz economy
scopes are very good and beautiful and inexpensive.  The displays are
outstanding!  The only reason I keep purchasing 20+ year old TDS3000
series scopes in the ability to set the mid reference levels when measuring
pulses.  In the UT industry, the pulse widths are measure at the 90%
reference levels verses the standard 50%.  I was in email with Siglents
tech support and engineering for a year.  They understood what I needed.
New firmware releases would come and still not that ability.  The best they
ever did was show a Python example of reading the waveform in and then I
could "calculate" the width at 90%. I was so frustrated. I do write a lot
of support code in VBA and VB6 that perhaps I could have done that, but I
could not make heads or tails out of their code example.  I really think it
was pure subterfuge.  I gave up and relegated the Siglent as a back-up;
this year, I will not even get it calibrated.  If they ever gave me the
ability to set the mid reference levels to whatever I wanted them to be, a
$700 brand new Siglent could easily replace a brand new $10K+++ Tektronix
TDS3000C series, or even used TDS3000 series.

On Sun, Jan 26, 2020 at 6:33 PM Dennis Tillman W7PF <@Dennis_Tillman_W7pF>
wrote:

Message #163848
Sent: Sunday, January 26, 2020 9:20 AM
Subject: Re: [TekScopes] 11801 questions - funny fan noise and light

Ragnar asks:  Are there any schematics on these [11801] boxes to be found?

By the 1960s Tek's Service Manuals (SM) were the finest in the industry.
They were a major selling point for Tek products. They were specifically
designed to give you all the information necessary to fix the instrument.
With the SM it was relatively inexpensive to maintain Tek instruments in
calibrated condition for a long time after they were purchased. The longer
those instruments could be maintained in good condition the lower the Total
Cost of Ownership (TCO) for the company that owned it. Eventually someone
would realize that the SMs were adversely affecting sales. With such good
SMs no one was in a hurry to buy new instruments from Tek when it was easy
to keep their old instruments calibrated and working perfectly.

In the mid-1980s someone in management did realize that Tek could make more
money by NOT including schematics in their service manuals. By the time the
11000 series of scopes appeared in 1986 schematics were banned from the
Service Manuals for new products. As far as I know there are no schematics
available anywhere for the 11K scopes. I tried on one occasion to get the
set for an 11K scope from someone at Tek but they were unable to locate
them. Since then Tek has tightly controlled the schematics for all of the
11K scopes and probably all other products as well. If a schematic set were
ever to escape from Tek's "clutches" and be released "into the wild" for a
supported product then returning it to the factory for repair would not be
the only way to get it fixed.

The disappearance of the schematics from Tek's service manuals was
impossible to miss when it happened. It occurred during a period in the
latter half of the 1980s when Tek was struggling financially with layoffs,
spin-offs, and decreased earnings almost every quarter.

When a product support department is a Cost Center the company recognizes
that good support is an intrinsic cost of producing a good product. The
company can charge more for its products because of the superior support
provided for them. The cost associated with providing this support is
recouped indirectly by a higher price the customer will pay for a
well-supported product.

When a product support department is a Profit Center it is expected to
generate revenue for a company by charging for support. This change will
help a struggling company's bottom line for a few years - which was
probably
why Tek chose to do it in 1986 - but eventually it will result in a loss of
customers and greater competition. In other words, this will come back to
bite you one day. Presumably the manager who is credited for this great
idea
will also know he has a few years to find a job elsewhere before the real
damage he has done becomes apparent to the board.

Why did Tek remove the schematics?
*  Without schematics Tek products have to be returned to the factory or
nearest repair center for repair. This is inconvenient for the customer
because travel time back and forth can be greater than the repair time. It
is dangerous because the instrument can be damaged in transit. It is
expensive to crate up and ship a large, heavy instrument. In addition,
since
the factory has a monopoly on repairs, they can charge more than the
customer's in-house repair department costs. This increases the customers
TCO. Tek makes money but it is at the expense of the customer who
eventually
will realize that Tek products are becoming as expensive to own as other
similar products from HP, LeCroy, etc..
*  More importantly, without schematics, Tek can arbitrarily shorten the
useful lifetime of their products by declaring a product obsolete and
ending
the repair service for it each time they introduce a new product that
improves on the old one. By no longer providing repair service for obsolete
products customers can be pressured to purchase the new replacement the
next
time their existing instrument breaks. Tek makes more money by selling new
products to replace the old ones they will no longer repair. The customer's
TCO goes up a lot in this scenario.

Each time the TCO goes up for the customer it encourages him to look at
competitive products and even low cost products from places like China
which
do not have the engineering excellence Tek is (was?) famous for. By making
support a Profit Center Tek makes more money in the short term but loses
customers in the long term when they purchase competitive products with a
lower TCO. In the very long term Tek loses the low end segment of the
market
to new competitors who see an opportunity to enter it with 1) products that
are cheaper than Tek can make, and 2) products the customer can justify
buying because they understand it was meant to be recycled rather than
repaired when it eventually breaks. The TCO is irrelevant for throw away
products.

In the very long term, supporting customers with a Profit Center model,
will
drive customers to reputable competitors with similar products that offer
them a choice of in-house support vs. Tek Profit Center support. Some
customers will realize they have another choice - buy an inexpensive
throw-away instrument for 1/4 to 1/3 of the price Tek charges. This creates
more competition at the low end of the marketplace where the profit margin
has eroded so deeply that Tek is no longer competitive.

Dennis Tillman W7PF








--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"


Re: Where have all the Schematics Gone?

Dave Brown
 

One of those turned up on the local club trading table a year or so back- working order- dunno who took it but could ask around in case they found a manual.(assuming you still have it?- most unlikely I guess!)
73
Dave, ZL3FJ

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Brad Thompson
Sent: Thursday, January 30, 2020 14:17
To: TekScopes@groups.io
Subject: Re: [TekScopes] Where have all the Schematics Gone?

Hello--

Quite a few years ago, I purchased for $5.00 a used Rohde & Schwarz SWOB Polyskop III instrument which comprised a vacuum-tube era sweep generator and a CRT display. IIRC, it was used as an alignment scope and a SNA of sorts. As might be assumed from the low purchase price, it came with a few problems.

I contacted R&S about obtaining a schematic and a service manual. Their asking price was $500.00; after explaining the 100:1 ratio between the manual and purchase price, I politely declined the purchase.

73--
Brad AA1IP


Re: debugging TM500 modules

Steph L
 

I also use a self contained TM502 power module for TM5xx repairs.

It is mounted on a rectangular piece of plywood for full length support, together with (short) timber rails either side to hold the repair in place and not stress PCB socket(s).

It has a rectangular hole in the base for underside adjustments, probing etc.

Steph


Re: Where have all the Schematics Gone?

Brad Thompson
 

Hello--

Quite a few years ago, I purchased for $5.00 a used Rohde & Schwarz SWOB Polyskop III
instrument which comprised a vacuum-tube era sweep generator and a CRT display. IIRC,
it was used as an alignment scope and a SNA of sorts. As might be assumed from the low
purchase price, it came with a few problems.

I contacted R&S about obtaining a schematic and a service manual. Their
asking price was $500.00; after explaining the 100:1 ratio between
the manual and purchase price, I politely declined the purchase.

73--
Brad  AA1IP


Re: 56 pins (TM500/5000 and 5000 series scope plug-ins) and 76 pins (7000 series scope plug-ins) connectors

Harvey White
 

Other than connecting to the appropriate power connections for that slot, the remaining pins in TM500 are dedicated to internal signals, often per plugin.  The idea is that if you wished to have a dedicated rack for TM500 equipment in a certain configuration (triggers wired to this, signals coming from that, etc), the front panel connections were duplicated enough that you could put particular plugins in dedicated slots, wire them on the back panel, and avoid all of the front panel connections.  From that point, you'd need only the connections to the device under test and whatever outputs you needed to outside the case.  Connections to a device under test could also be made with a dedicated connector on the back panel.

Harvey

On 1/29/2020 5:35 PM, Ke-Fong Lin wrote:
For TM500/5000, they are basically only power rails, along with with ECB to power transistors. I guess the plug-in specific top pins are not so much needed for repair.
In particular, some power pins are duplicates, for example, the 4 common return pins for 8V/11VDC for instance, a single 22 AWG wire will do.

For the 7000 series plug-ins, there's just too many pins and are almost all used.
So I plan to use some ribbon cable, with may be some individual wires for power (i.e. +/- 50 & 15 VDC), and some coaxial wires for the signal pins.
These are readily available at Farnell and Mouser.
I've not much experience in RF signals, but I guess that with coax on the "critical" signal pins, that should be sufficient for <= 100MHz, maybe even calibrating.




Re: Where have all the Schematics Gone?

KeepIt SimpleStupid
 

I called tech support for a Nuvo NV-MI1 mute interface for a doorbell and phone  https://www.legrand.us/nuvo/audio-video/brackets-accessories/accessories/mi1.aspx

I asked how it worked and what the output was.
The tech support guy was flabbergasted that he had no information on the device.In fact, he even asked me if they made it.

On Wednesday, January 29, 2020, 3:09:32 PM EST, David Kuhn <daveyk021@...> wrote:

I agree. At GE Inspection Technologies, the same thing happened after GE
purchased us.  Even our Sales Representatives with their own authorized
service departments could not get schematics.  Then the factory repair
service became a profit center and part prices went through the roof.
Well, GEIT is not more.  What is left of the company is a shell of itself.
The US Plant in Pennsylvania shut down, production moved between Southern
Ireland and Slovakia.  Service, without the experienced techs to the
Houston, TX area.  Now their name changed (GEIT is no more) and their
product offering a ghost of what it used to be.  Meanwhile, their
competitors are going great guns.

As far as Chinese Scopes. Siglent is quite good.  Even their 200MHz economy
scopes are very good and beautiful and inexpensive.  The displays are
outstanding!  The only reason I keep purchasing 20+ year old TDS3000
series scopes in the ability to set the mid reference levels when measuring
pulses.  In the UT industry, the pulse widths are measure at the 90%
reference levels verses the standard 50%.  I was in email with Siglents
tech support and engineering for a year.  They understood what I needed.
New firmware releases would come and still not that ability.  The best they
ever did was show a Python example of reading the waveform in and then I
could "calculate" the width at 90%. I was so frustrated. I do write a lot
of support code in VBA and VB6 that perhaps I could have done that, but I
could not make heads or tails out of their code example.  I really think it
was pure subterfuge.  I gave up and relegated the Siglent as a back-up;
this year, I will not even get it calibrated.  If they ever gave me the
ability to set the mid reference levels to whatever I wanted them to be, a
$700 brand new Siglent could easily replace a brand new $10K+++ Tektronix
TDS3000C series, or even used TDS3000 series.

On Sun, Jan 26, 2020 at 6:33 PM Dennis Tillman W7PF <@Dennis_Tillman_W7pF>
wrote:

Message #163848
Sent: Sunday, January 26, 2020 9:20 AM
Subject: Re: [TekScopes] 11801 questions - funny fan noise and light

Ragnar asks:  Are there any schematics on these [11801] boxes to be found?

By the 1960s Tek's Service Manuals (SM) were the finest in the industry.
They were a major selling point for Tek products. They were specifically
designed to give you all the information necessary to fix the instrument.
With the SM it was relatively inexpensive to maintain Tek instruments in
calibrated condition for a long time after they were purchased. The longer
those instruments could be maintained in good condition the lower the Total
Cost of Ownership (TCO) for the company that owned it. Eventually someone
would realize that the SMs were adversely affecting sales. With such good
SMs no one was in a hurry to buy new instruments from Tek when it was easy
to keep their old instruments calibrated and working perfectly.

In the mid-1980s someone in management did realize that Tek could make more
money by NOT including schematics in their service manuals. By the time the
11000 series of scopes appeared in 1986 schematics were banned from the
Service Manuals for new products. As far as I know there are no schematics
available anywhere for the 11K scopes. I tried on one occasion to get the
set for an 11K scope from someone at Tek but they were unable to locate
them. Since then Tek has tightly controlled the schematics for all of the
11K scopes and probably all other products as well. If a schematic set were
ever to escape from Tek's "clutches" and be released "into the wild" for a
supported product then returning it to the factory for repair would not be
the only way to get it fixed.

The disappearance of the schematics from Tek's service manuals was
impossible to miss when it happened. It occurred during a period in the
latter half of the 1980s when Tek was struggling financially with layoffs,
spin-offs, and decreased earnings almost every quarter.

When a product support department is a Cost Center the company recognizes
that good support is an intrinsic cost of producing a good product. The
company can charge more for its products because of the superior support
provided for them. The cost associated with providing this support is
recouped indirectly by a higher price the customer will pay for a
well-supported product.

When a product support department is a Profit Center it is expected to
generate revenue for a company by charging for support. This change will
help a struggling company's bottom line for a few years - which was
probably
why Tek chose to do it in 1986 - but eventually it will result in a loss of
customers and greater competition. In other words, this will come back to
bite you one day. Presumably the manager who is credited for this great
idea
will also know he has a few years to find a job elsewhere before the real
damage he has done becomes apparent to the board.

Why did Tek remove the schematics?
*  Without schematics Tek products have to be returned to the factory or
nearest repair center for repair. This is inconvenient for the customer
because travel time back and forth can be greater than the repair time. It
is dangerous because the instrument can be damaged in transit. It is
expensive to crate up and ship a large, heavy instrument. In addition,
since
the factory has a monopoly on repairs, they can charge more than the
customer's in-house repair department costs. This increases the customers
TCO. Tek makes money but it is at the expense of the customer who
eventually
will realize that Tek products are becoming as expensive to own as other
similar products from HP, LeCroy, etc..
*  More importantly, without schematics, Tek can arbitrarily shorten the
useful lifetime of their products by declaring a product obsolete and
ending
the repair service for it each time they introduce a new product that
improves on the old one. By no longer providing repair service for obsolete
products customers can be pressured to purchase the new replacement the
next
time their existing instrument breaks. Tek makes more money by selling new
products to replace the old ones they will no longer repair. The customer's
TCO goes up a lot in this scenario.

Each time the TCO goes up for the customer it encourages him to look at
competitive products and even low cost products from places like China
which
do not have the engineering excellence Tek is (was?) famous for. By making
support a Profit Center Tek makes more money in the short term but loses
customers in the long term when they purchase competitive products with a
lower TCO. In the very long term Tek loses the low end segment of the
market
to new competitors who see an opportunity to enter it with 1) products that
are cheaper than Tek can make, and 2) products the customer can justify
buying because they understand it was meant to be recycled rather than
repaired when it eventually breaks. The TCO is irrelevant for throw away
products.

In the very long term, supporting customers with a Profit Center model,
will
drive customers to reputable competitors with similar products that offer
them a choice of in-house support vs. Tek Profit Center support. Some
customers will realize they have another choice - buy an inexpensive
throw-away instrument for 1/4 to 1/3 of the price Tek charges. This creates
more competition at the low end of the marketplace where the profit margin
has eroded so deeply that Tek is no longer competitive.

Dennis Tillman W7PF







Re: 56 pins (TM500/5000 and 5000 series scope plug-ins) and 76 pins (7000 series scope plug-ins) connectors

Ke-Fong Lin
 

For TM500/5000, they are basically only power rails, along with with ECB to power transistors. I guess the plug-in specific top pins are not so much needed for repair.
In particular, some power pins are duplicates, for example, the 4 common return pins for 8V/11VDC for instance, a single 22 AWG wire will do.

For the 7000 series plug-ins, there's just too many pins and are almost all used.
So I plan to use some ribbon cable, with may be some individual wires for power (i.e. +/- 50 & 15 VDC), and some coaxial wires for the signal pins.
These are readily available at Farnell and Mouser.
I've not much experience in RF signals, but I guess that with coax on the "critical" signal pins, that should be sufficient for <= 100MHz, maybe even calibrating.


Re: TEK514 needs new 5V4G tube

DaveH52
 


Re: 5111 Storage Scope Loss of -30VDC

p mc
 

...oh yeah and...

Did your friend pass on any of the story of how your scope ended up unused for 40 years?

pmc


Re: 5111 Storage Scope Loss of -30VDC

p mc
 

No idea about the "stuff". Nor do I have a 5111 at hand to look at.

Does the scope work with the storage board disconnected? I can't confirm, but I think it should.


Re: Where have all the Schematics Gone?

David Kuhn
 

I agree. At GE Inspection Technologies, the same thing happened after GE
purchased us. Even our Sales Representatives with their own authorized
service departments could not get schematics. Then the factory repair
service became a profit center and part prices went through the roof.
Well, GEIT is not more. What is left of the company is a shell of itself.
The US Plant in Pennsylvania shut down, production moved between Southern
Ireland and Slovakia. Service, without the experienced techs to the
Houston, TX area. Now their name changed (GEIT is no more) and their
product offering a ghost of what it used to be. Meanwhile, their
competitors are going great guns.

As far as Chinese Scopes. Siglent is quite good. Even their 200MHz economy
scopes are very good and beautiful and inexpensive. The displays are
outstanding! The only reason I keep purchasing 20+ year old TDS3000
series scopes in the ability to set the mid reference levels when measuring
pulses. In the UT industry, the pulse widths are measure at the 90%
reference levels verses the standard 50%. I was in email with Siglents
tech support and engineering for a year. They understood what I needed.
New firmware releases would come and still not that ability. The best they
ever did was show a Python example of reading the waveform in and then I
could "calculate" the width at 90%. I was so frustrated. I do write a lot
of support code in VBA and VB6 that perhaps I could have done that, but I
could not make heads or tails out of their code example. I really think it
was pure subterfuge. I gave up and relegated the Siglent as a back-up;
this year, I will not even get it calibrated. If they ever gave me the
ability to set the mid reference levels to whatever I wanted them to be, a
$700 brand new Siglent could easily replace a brand new $10K+++ Tektronix
TDS3000C series, or even used TDS3000 series.

On Sun, Jan 26, 2020 at 6:33 PM Dennis Tillman W7PF <@Dennis_Tillman_W7pF>
wrote:

Message #163848
Sent: Sunday, January 26, 2020 9:20 AM
Subject: Re: [TekScopes] 11801 questions - funny fan noise and light

Ragnar asks: Are there any schematics on these [11801] boxes to be found?

By the 1960s Tek's Service Manuals (SM) were the finest in the industry.
They were a major selling point for Tek products. They were specifically
designed to give you all the information necessary to fix the instrument.
With the SM it was relatively inexpensive to maintain Tek instruments in
calibrated condition for a long time after they were purchased. The longer
those instruments could be maintained in good condition the lower the Total
Cost of Ownership (TCO) for the company that owned it. Eventually someone
would realize that the SMs were adversely affecting sales. With such good
SMs no one was in a hurry to buy new instruments from Tek when it was easy
to keep their old instruments calibrated and working perfectly.

In the mid-1980s someone in management did realize that Tek could make more
money by NOT including schematics in their service manuals. By the time the
11000 series of scopes appeared in 1986 schematics were banned from the
Service Manuals for new products. As far as I know there are no schematics
available anywhere for the 11K scopes. I tried on one occasion to get the
set for an 11K scope from someone at Tek but they were unable to locate
them. Since then Tek has tightly controlled the schematics for all of the
11K scopes and probably all other products as well. If a schematic set were
ever to escape from Tek's "clutches" and be released "into the wild" for a
supported product then returning it to the factory for repair would not be
the only way to get it fixed.

The disappearance of the schematics from Tek's service manuals was
impossible to miss when it happened. It occurred during a period in the
latter half of the 1980s when Tek was struggling financially with layoffs,
spin-offs, and decreased earnings almost every quarter.

When a product support department is a Cost Center the company recognizes
that good support is an intrinsic cost of producing a good product. The
company can charge more for its products because of the superior support
provided for them. The cost associated with providing this support is
recouped indirectly by a higher price the customer will pay for a
well-supported product.

When a product support department is a Profit Center it is expected to
generate revenue for a company by charging for support. This change will
help a struggling company's bottom line for a few years - which was
probably
why Tek chose to do it in 1986 - but eventually it will result in a loss of
customers and greater competition. In other words, this will come back to
bite you one day. Presumably the manager who is credited for this great
idea
will also know he has a few years to find a job elsewhere before the real
damage he has done becomes apparent to the board.

Why did Tek remove the schematics?
* Without schematics Tek products have to be returned to the factory or
nearest repair center for repair. This is inconvenient for the customer
because travel time back and forth can be greater than the repair time. It
is dangerous because the instrument can be damaged in transit. It is
expensive to crate up and ship a large, heavy instrument. In addition,
since
the factory has a monopoly on repairs, they can charge more than the
customer's in-house repair department costs. This increases the customers
TCO. Tek makes money but it is at the expense of the customer who
eventually
will realize that Tek products are becoming as expensive to own as other
similar products from HP, LeCroy, etc..
* More importantly, without schematics, Tek can arbitrarily shorten the
useful lifetime of their products by declaring a product obsolete and
ending
the repair service for it each time they introduce a new product that
improves on the old one. By no longer providing repair service for obsolete
products customers can be pressured to purchase the new replacement the
next
time their existing instrument breaks. Tek makes more money by selling new
products to replace the old ones they will no longer repair. The customer's
TCO goes up a lot in this scenario.

Each time the TCO goes up for the customer it encourages him to look at
competitive products and even low cost products from places like China
which
do not have the engineering excellence Tek is (was?) famous for. By making
support a Profit Center Tek makes more money in the short term but loses
customers in the long term when they purchase competitive products with a
lower TCO. In the very long term Tek loses the low end segment of the
market
to new competitors who see an opportunity to enter it with 1) products that
are cheaper than Tek can make, and 2) products the customer can justify
buying because they understand it was meant to be recycled rather than
repaired when it eventually breaks. The TCO is irrelevant for throw away
products.

In the very long term, supporting customers with a Profit Center model,
will
drive customers to reputable competitors with similar products that offer
them a choice of in-house support vs. Tek Profit Center support. Some
customers will realize they have another choice - buy an inexpensive
throw-away instrument for 1/4 to 1/3 of the price Tek charges. This creates
more competition at the low end of the marketplace where the profit margin
has eroded so deeply that Tek is no longer competitive.

Dennis Tillman W7PF







Re: Guernsey Island 2445

Mlynch001
 

I just bought a 465 that is an early to mid 70's model, it has "TEKTRONIX GUERNSEY LTD. Guernsey Channel Islands" on an ID plate on the back panel and it has a 6 digit Serial number up front "103496".

--
Michael Lynch
Dardanelle, AR


Re: Guernsey Island 2445

Chuck Harris
 

Hi Charlie,

It seems like they dithered about whether to use numbers,
or letters, or numbers and letters, to identify the factory.

In 1979, the 465B manual seemed silent on the issue.

In 1980, the 468 manual listed:
B000000 as Beaverton,
100000 as Guernsey,
200000 as UK,
300000 as Japan,
700000 as Holland

In 1983, the 2465 manuals listed:
B000000 as Beaverton,
100000 as Guernsey,
200000 as UK,
300000 as Japan, and
700000 as Holland.

In 1988, the 2465B manuals listed:
B010000 as Beaverton,
E200000 as United Kingdom,
J300000 as Japan, and
H700000 as Holland.

And said that instruments manufactured by Tek by external
vendors are assigned a two digit alpha code to identify the
country of manufacture... (e.g. JP for Japan, HK for Hong Kong,
IL for Israel, ...)

Not exactly consistent.

Do you have any insight on the conversion between Beaverton
serial numbers ... and their revision sheets ... and the
other factory's serial numbers?

My idea is only a guess loosely based on a very old memory
of a discussion I had with a former tek engineer.

-Chuck Harris

Charlie.c wrote:

Sounds like the rules are the rules until there are not.
That was all in the 2” thick employee handbook I was handed the day I joined tek in the the 80’s.😊




Re: Guernsey Island 2445

Charlie Conger
 

Sounds like the rules are the rules until there are not.
That was all in the 2” thick employee handbook I was handed the day I joined tek in the the 80’s.😊


Re: 56 pins (TM500/5000 and 5000 series scope plug-ins) and 76 pins (7000 series scope plug-ins) connectors

John Griessen
 

On 1/29/20 9:21 AM, Harvey White wrote:
Ds.
Now with the IDC cables, and no coax, you can't use it for frequency checking, but the idea was to do functional testing and repair, not frequency test and alignment.

Frequency checking up to 100MHz is possible with my more laboriously assembled kits with 24 gauge wire and coax like the Tek 7K flex originals. Voltage 3 dB down was measured by Jerry M. at 130MHz with them.

I'll stock some more of those parts when I get moved to Albuquerque.