Date   
Re: TEK514 needs new 5V4G tube

 

Hi Steve,
Is there any reason you can't buy a 5V4G? There are 123 of them on eBay at the moment. Prices start at $12 for them and go up.
I can test it for you to confirm its good if want to send it to me.
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Richard Solomon
Sent: Sunday, January 26, 2020 4:33 PM
To: TekScopes <TekScopes@groups.io>
Subject: Re: [TekScopes] TEK514 needs new 5V4G tube

This may be blasphemy, but you
could replace the rectifier tube with
a couple of diodes.

You may need a small resistance to
adjust for the lower voltage drop in
the diodes.

73, Dick, W1KSZ

On Sun, Jan 26, 2020 at 4:34 PM Roy Morgan <k1lky68@...> wrote:

Steve,

I would strongly suspect a shorted filter cap in that supply.

If you have an external variable B+ supply, bring the voltage up VERY
SLOWLY at the tube cathode while monitoring the current. (Scope power
off)

Roy Morgan
K1LKY Western Mass

On Jan 26, 2020, at 6:10 PM, Steve Hendrix
<SteveHx@...>
wrote:

Okay, it's a "valve" for our limey friends!

... One rectifier tube right next to that monster power transformer
started getting extra hot within seconds of power-on, and then started
arcing and making a nice arc lamp. ...







--
Dennis Tillman W7PF
TekScopes Moderator

Re: TEK514 needs new 5V4G tube

Harvey White
 

Considering the cost for a 5V, which IIRC is a rectifier with an indrectly heated cathode (*many* years ago).  You might want to take some silicon rectifiers and put them in, substituting for the 5V4.  You may get a bit hotter B+ out of the combo, and I've heard that some people put some fairly large wattage resistors in series to limit the surge, but I'd certainly consider that fix for AU $45.00.  (which even at the last rate I remember is USD22.00 and that's a big bunch).  I suspect that 1N4006 might be a good candidate.

If you had an octal tube base you could build it into that.

Harvey

On 1/26/2020 6:10 PM, Steve Hendrix wrote:
Okay, it's a "valve" for our limey friends!

Today I was able to do some more troubleshooting with my dad and my sons, on Dad's TEK514. I took along my thermal camera to help track down the short that was blowing the inlet fuse. Turned out i didn't need it, but it helped confirm. One rectifier tube right next to that monster power transformer started getting extra hot within seconds of power-on, and then started arcing and making a nice arc lamp. I've done a bit of searching and it seems the audiophiles like these tubes; the best I could find was AU$55 for a pair on eBay. Dunno how much shipping would be from down under. Fairly simple fix, to swap out a tube - if that's the only problem. But we checked all the electrolytic caps with an ohmmeter and none seemed to be shorted nor open. Looking for any thoughts on a good source for the tube, and/or whether it's a worthwhile fix.

Steve Hendrix


Type O plugin with Power Supply

Glenn Little
 

Many years ago I bought this from Deane Kidd.
It has been in my back room since.
The plugin is serial 000096.
Serial 000098 sold for $100.00 as a parts unit.
The power supply has no type number on it.
I suspect that is may be a prototype.
The power supply is missing at least two tubes and one transistor and has no cover.
A picture is attached.
I would like to get $100.00 plus shipping for the plugin and power supply.
Is anyone interested?

Glenn

--
-----------------------------------------------------------------------
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: TEK514 needs new 5V4G tube

Richard Solomon
 

This may be blasphemy, but you
could replace the rectifier tube with
a couple of diodes.

You may need a small resistance to
adjust for the lower voltage drop in
the diodes.

73, Dick, W1KSZ

On Sun, Jan 26, 2020 at 4:34 PM Roy Morgan <k1lky68@...> wrote:

Steve,

I would strongly suspect a shorted filter cap in that supply.

If you have an external variable B+ supply, bring the voltage up VERY
SLOWLY at the tube cathode while monitoring the current. (Scope power off)

Roy Morgan
K1LKY Western Mass

On Jan 26, 2020, at 6:10 PM, Steve Hendrix <SteveHx@...>
wrote:

Okay, it's a "valve" for our limey friends!

... One rectifier tube right next to that monster power transformer
started getting extra hot within seconds of power-on, and then started
arcing and making a nice arc lamp. ...



Re: Your generosity is STUNNING!

 

Hi Michael,
A bank account is definitely something we have to do. It is a little tricky because Michael is in Canada and I am in the US so we have to be sure we comply with the laws of both nations.

We also need to put it in an account where currency variations won't adversely affect it. That would probably be the US.

In April 2011 it cost $0.95CD to buy $1.00US. The Canadian dollar was worth more than the US dollar.
Today it costs $1.32CD to buy $1.00US. A Canadian dollar is worth $0.76US.

Since Groups,io is in the US it might be easier to have the bank account in the US.

I am hopeful Groups.io will implement a payment option that would let us pay 5 years at a time. That would be even better.
Michael Dunn says I shouldn't hold my breath.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Michael A. Terrell
Sent: Sunday, January 26, 2020 12:20 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Your generosity is STUNNING!

Why not set up a bank account for it, and Autopay for Groups.io? It could also be used to fund group purchases for custom made replacement parts, when you are short a person or two. Put the money back into the account when the extras are sold. We did this for a computer club, in the '80s. It was registered as a non profit, but it wouldn't be difficult to do that for a group this size.

On Sun, Jan 26, 2020 at 12:46 AM Dennis Tillman W7PF <@Dennis_Tillman_W7PF>
wrote:

Hi Raymond,

You are one of the few people who did correctly identify your
contribution in my list.
This is the information I have on your contribution:
### DENNIS' LOCAL TIME $$$ STATUS CONTRIBUTOR
PAYPAL TRANSACTION
128 Wed 1/1/2020 2:50 PM $22.57 TO BE RETURNED Raymond Domp
Frank 9SK435895B100851N

Yes, Siggi is correct PayPal did this for everyone. They also obscure
the time you made your contribution because they strip out your UTC
offset (time zone) so I can’t tell the hour of the day you sent it.
The minutes are close however.

Thank you for your contribution. We received too much money to keep it
all so we will be refunding anything above $10.00 as soon as I have
had a chance to contact everyone who asked for confirmation that I
received their contribution.

Dennis

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
Raymond Domp Frank
Sent: Monday, January 20, 2020 9:45 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Your generosity is STUNNING!

Dennis,
My transaction could well be
9SK43*******0851N $22.57 TO BE REFUNDED
That's the only transaction in your list for the amount that I transferred.
Siggi may be right in assuming that Paypal references change between
sender and receiver (nice!) for international transactions.

Raymond








--
Dennis Tillman W7PF
TekScopes Moderator

Re: Tek CRTs supplied to competing manufacturers

 

This is documented in the book: Winning With People: The first 40 years of Tektronix by Lee.
Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of george gonzalez
Sent: Sunday, January 26, 2020 11:55 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek CRTs supplied to competing manufacturers

I think it was the other way around, Tek used to buy CRTs from Dumont and RCA but found out they were getting the below average CRTs. This came to light when some university bought like 50 CRTs and some alert Tek person noticed the tubes were not in serial number order and they all were extremely bright and sharp, better than the ones sent to Tektronix. This spurred Tek to start up their own CRT factory. Expensive but had superb results.

On Friday, January 24, 2020, Greg Muir via Groups.Io <big_sky_explorer= yahoo.com@groups.io> wrote:

Thanks, Dennis.

I did think it came from a fairly reputable source. But the years
that passed after reading of it made it rather fuzzy in the ol' brain.

As for another title, i would add "...and why was it subject to such
suffering under control of a holding company?"

("Big fish eating smaller fish")

Greg







--
Dennis Tillman W7PF
TekScopes Moderator

Re: TEK514 needs new 5V4G tube

Roy Morgan
 

Steve,

I would strongly suspect a shorted filter cap in that supply.

If you have an external variable B+ supply, bring the voltage up VERY SLOWLY at the tube cathode while monitoring the current. (Scope power off)

Roy Morgan
K1LKY Western Mass

On Jan 26, 2020, at 6:10 PM, Steve Hendrix <SteveHx@...> wrote:

Okay, it's a "valve" for our limey friends!

... One rectifier tube right next to that monster power transformer started getting extra hot within seconds of power-on, and then started arcing and making a nice arc lamp. ...

Where have all the Schematics Gone?

 

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: Scope tester on Ebay

Miguel Work
 

Re: Tek CRTs supplied to competing manufacturers

 

On Sun, Jan 26, 2020 at 11:56 PM, Greg Muir wrote:


Do you or anyone else have a copy handy of "Winning with People; The first 40
years of Tektronix" to confirm this? I can’t seem to find my copy at the
moment.
From "Winning with People; The first 40 years of Tektronix", page 12:

"Why did Tek make its own cathode-ray tubes? Because neither Dumont's nor RCA's were good enough and Tel thought it could do better".

Raymond

TEK514 needs new 5V4G tube

Steve Hendrix
 

Okay, it's a "valve" for our limey friends!

Today I was able to do some more troubleshooting with my dad and my sons, on Dad's TEK514. I took along my thermal camera to help track down the short that was blowing the inlet fuse. Turned out i didn't need it, but it helped confirm. One rectifier tube right next to that monster power transformer started getting extra hot within seconds of power-on, and then started arcing and making a nice arc lamp. I've done a bit of searching and it seems the audiophiles like these tubes; the best I could find was AU$55 for a pair on eBay. Dunno how much shipping would be from down under. Fairly simple fix, to swap out a tube - if that's the only problem. But we checked all the electrolytic caps with an ohmmeter and none seemed to be shorted nor open. Looking for any thoughts on a good source for the tube, and/or whether it's a worthwhile fix.

Steve Hendrix

Re: Tek CRTs supplied to competing manufacturers

Greg Muir
 

George,

Do you or anyone else have a copy handy of "Winning with People; The first 40 years of Tektronix" to confirm this? I can’t seem to find my copy at the moment.

Thanks,

Greg

On 01-26-2018 at 12:55 pm George Gonzales wrote:
“I think it was the other way around. Tek used to buy CRTs from Dumont and RCA but found out they were getting below average CRTs….”

Re: 11801 questions - funny fan noise and light

 

Hi Ragnar,
Maybe Tek switched to these kinds of fans to make their instrument more
energy efficient.
With the heightened interest in being ecologically responsible many
companies, like Tektronix for example, have made a concerted effort to make
their equipment more efficient. Every watt used by any electronic device
ultimately ends up as heat that other machines (like fans and air
conditioners) have to remove. The engineers designing new equipment know the
savings that will come from every wasted watt they can eliminate result in a
savings of several watts. Temperature sensing fans save power by not running
at all until needed and then only running as fast and as long as necessary
to remove the heat from the instrument.

Dennis Tillman W7PF

-----Original Message-----
From: Ragnar S
Sent: Sunday, January 26, 2020 9:20 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] 11801 questions - funny fan noise and light

Thank you gentlemen for your replies!
So it is unclear if it is supposed to do this, but it is at least not
unheard of.

I checked the voltages on the feed wires to the fan relative chassis ground.
From start, the positive wire has about +6.3 V and the negative about +0.7
V.
When the fan revving occurs, the negative wire goes to about -6 V for about
35 ms, making a total voltage over the fan of about 12 V. For some reason
the pulses come irregularly, around 1 or a few times per second.

My current hypotheses is that the intention is to regulate the speed of the
fan, but I would be surprised if this actually is how it was designed to
work. It is somewhat annoying. :-)

Are there any schematics on these boxes to be found?

Also - the neon (?) light in the power supply, right behind the fan, that
starts to flicker as soon as it has power (also in standby mode) - do you
guys have that too?

Thanks for you help and best regards,

Ragnar

On 25 Jan 2020, at 16:01, Chuck Harris <cfharris@...> wrote:

Mine is normal until after the scope has been turned on for about 30
minutes, and then it starts going "Brummm..... Brummm..."

I suspect a capacitor failure, as it is annoying, and would have
caused notice if it were a "normal" condition.

Annoying, though it may be, I can't see how it would cause any harm...
unless it presages a total failure.

What it isn't is a bearing failure, or lack of lubrication. My fan
spins for what seems like half a minute after power is turned off.

-Chuck Harris

Reginald Beardsley via Groups.Io wrote:
I don't recall mine ever doing that. I'm very sensitive to noise as I
investigate anything I can't identify, so I think I would have noticed it.

A fan on one of my HP Z400 workstations was doing that. I shut it down
to reduce the heat in the room and when I tried to boot it the fan was dead.
I've not had time to correct it yet.

Good luck,
Reg



--
Dennis Tillman W7PF
TekScopes Moderator

FS: Tektronix 1140A load & current fixture

Brad Thompson
 

Hello--

I'm offering FS one only Tektronix model 1140A load and current-shunt fixture
That's in very good mechanical but unknown electrical condition and
hence is offered as-is.

The 1140A test fixture is designed  for calibrating 1140A [[[coincidence? I think not...]]]]
power supplies, but based on its schematic and operating manual as shown here...

http://w140.com/tekwiki/wiki/067-0764-00

...It's likely very useful for calibrating and troubleshooting other power supplies.

I'm asking $30.00 plus shipping cost.

Questions welcomed, PayPal honored.

Thanks, and 73--

Brad  AA1IP

Re: TDS3012B to TDS3052B upgrade

Tom B
 

Hello Håkan,

Thank you for the information.  I think this tells me what I want to know.   It is good to know that the hardware is all the same.

I also have a TDS2024 but I don't have any plans to change that one.

I don't own any calibration equipment so I don't think your software will do me any good.

Tom

On 1/26/2020 7:32 AM, zenith5106 wrote:
On Sun, Jan 26, 2020 at 04:55 AM, Tom B wrote:

I have seen a lot of postings from people who have upgraded the bandwidth of
their TDS3000 scopes with firmware.   I have a TDS3012B that I was thinking
about doing that with but it seems strange that you could go from 100MHz to
500MHz without any hardware changes.  What I want to know is; how well does
this work?  Are there any issues to watch out for?
I have done that upgrade on several TDS3000 scopes including my own TDS3014B. It works fine
and it does not need an adjustment after the change. It's done with GPIB. It can also be done on
TDS200 and TDS1000/2000 but they need a full adjustments sequence to be done.

I have written several softwares to do a Performance Check on most of the older TDS's and for
the TDS's mentioned above I included a procedure to change the type. Initially I had an idea to
charge a small fee for that specific function. I have later abandoned this idea but until the software
has been changed you will need to get a key from me.

Find it here: https://urldefense.com/v3/__http://www.hakanh.com/dl/TDS_pv.htm__;!!KfGNmQmE!yrE_0JSiIWARxe7y9YW-lbIqsXEU4CHzxS-GQGAYYzlbrLpDm40Tmx3YVrQn$

Re: Guernsey Island 2445

David DiGiacomo
 

On Sun, Jan 26, 2020 at 12:35 PM Chuck Harris <cfharris@...> wrote:

I am pretty sure that the last 5 digits between Guernsey
and Beaverton units are not unique, but rather, are sync'd
to each other so the change orders apply.

In other words, you can have a B012345 and an 8012345 scope,
and each will use the revisions specific to B012345.
There have been a few times when Håkan looked up the cross references
in the modification summaries, and the last 5 digits were not synced,
e.g.:

https://groups.io/g/TekScopes/message/60534

"In a very limited cross reference for mods B230000 corresponds to
108670 and B327100 to 110610 so I would say your Guernsey 7B53A
is the newest one."

Re: Guernsey Island 2445

 

On Sun, Jan 26, 2020 at 10:17 PM, Chuck Harris wrote:


The primary thing I was trying to relate is the last
5 digits determines which engineering change orders
apply to your instrument.
I'm pretty sure that's incorrect across serial numbers from different countries of manufacture, Chuck, but I'm happy to check and provide (dis)proof when I'm back in the lab...
Unless unwelcome signs of old age have set in, ISTR that's exactly what many of us (mostly non-US based) have had to deal with for years.
It is one unfortunate thing that I have never understood from Tek.

Raymond

Re: Guernsey Island 2445

 

On Sun, Jan 26, 2020 at 08:50 PM, n4buq wrote:


Did all the Guernsey serial numbers begin with 8? Mine has a six-digit serial
number that begins with 1.
As I wrote elsewhere, AFAIK no serial numbers starting with 8 exist and 1... means made in Guernsey.

Raymond

Re: Guernsey Island 2445

 

On Sun, Jan 26, 2020 at 08:35 PM, Chuck Harris wrote:


In other words, you can have a B012345 and an 8012345 scope,
and each will use the revisions specific to B012345.
I don't think that's the case:
AFAIK, no regular serial numbers starting with 8 exist
Numbers starting with B were US-made (Beaverton)
Numbers starting with 1 were Guernsey-made
Numbers starting with 2 were UK-made
Numbers starting with 3 were Japan made
Numbers starting with 7 and those with H were Heerenveen made
I've been told that sometimes, letter-codes were used

All this applies at least from very late 60's to early 70's. AFAIK, all 7K-series serial numbers obey these rules.

I have a few 'scopes made in Heerenveen (The Netherlands, NL) with very low serial numbers (<200 and even <100 are pretty common) that are obviously much newer than that number would suggest.
AFAIK, regular Beaverton made 'scopes never carried such low serial numbers.
I have always assumed that production of a particular model in NL and Guernsey just started later than in the US and nicely rounded number series weren't used, explaining low non-Beaverton numbers applying to much higher Beaverton revisions. My two NL-made 7854's are examples. Also, creating a gap and continuing numbering from e.g. 250000 definitely hasn't been synchronized between Beaverton and non-Beaverton. One example of this are the many 465 portables made in Heerenveen, which are on both sides of the 250000 range and never carry a > 250000 serial number. The same holds true (MM) for 2465(X,A,B)'s made in Heerenveen.

Re: Guernsey Island 2445

Chuck Harris
 

Everything you want to know about serial numbers is in
the front of the 2445 manual, usually on the copyright
page.

I was using "8" as a sample prefix, Beaverton is "B",
Gurnsey is "1", UK is "2", Sony is "3", and Holland
is "7"

The primary thing I was trying to relate is the last
5 digits determines which engineering change orders
apply to your instrument.

-Chuck Harris

n4buq wrote:

Okay. Apparently I inferred too much from the example.

Thanks,
Barry - N4BUQ

----- Original Message -----