Date   

Re: Tektronix 2465 for sale ...

Tony Fleming
 

Despite having less and less room, if I was near you, you would have a
customer!
If you can't sell it, donate it to a club or school, church or other places
and have a great feeling about helping others!
Wish you good luck and happy 2020!

On Sun, Jan 5, 2020 at 5:26 PM mosaicmerc via Groups.Io <mosaicmerc=
yahoo.com@groups.io> wrote:

I have a couple working 2465s i don't use, but I am not in Continental
USA...so I could maybe scrap out a m'board from 1






Re: Tektronix 2465 for sale ...

mosaicmerc
 

I have a couple working 2465s i don't use, but I am not in Continental USA...so I could maybe scrap out a m'board from 1


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Richard Solomon <dickw1ksz@...>
 

Whoa Nelly, where did I say that ..."vacuum
tubes are history"... ??

Not in this shack where I have in the AM
station an Elmac AF-67 and Halli SX-117
in daily use. When I feel "continental", I
fire up the Geloso Twins.

What I did ask was what use a 570 had
in todays real world.

I have doubts that any of the tube sellers
on e-Bay use a 570 to characterize any
of the "Matched Pairs" they sell. More
likely they use a Tube Tester and if the
meter reads close they are matched.

The AudioPhool market is an aberration
that I have nothing to do with. $500 for
a Line Cord ??? Give me a break.

Going back now to work on restoring
a TMC GPR-90 that some hack really
messed up.

Tnx es 73, Dick, W1KSZ

On Sun, Jan 5, 2020 at 3:05 PM peter bunge <bunge.pjp@...> wrote:

I had a University EE Summer Student who did not know how a tube worked so
I broke a 6SN7 and showed him the parts. He then said tubes were no longer
used so I asked him what he thought was in our 100kW RF amp that drove the
Superconducting Cyclotron, and how he would replace it with Solid State. I
then told him his theories MIGHT work but how would Solid State handle the
huge reflected power often sent back to the amplifier, and survive?
I'm not sure how I would test a 4CW200,000 (if I remember the 200kW water
cooled tube number correctly). The HV power supply was bigger than our
kitchen.

On Sun, Jan 5, 2020 at 4:01 PM Dennis Tillman W7PF <@Dennis_Tillman_W7pF>
wrote:

Hi Richard,

It may seem that vacuum tubes are history but nothing could be further
from the truth. To my amazement I have sold almost 200 of my little VTCT
Adapter boards. That really surprised me. That gives people a way to
avoid
paying $5,000 for a 570 Tube Tester. It still costs at least a few
hundred
dollars with my adapter because you still need some kind of transistor
curve tracer and a tube tester.

There are many applications that use tubes these days. Vacuum tube
manufacturing never went away and now the Russians are producing a lot of
them. But there are many other companies also doing it. A top of the line
vacuum tube audio amplifier will set you back $100,000 and eventually the
push-pull output tubes will need balancing or replacing. Likewise, rock
guitarists all use tube amplifiers, not solid state. The sound of tube
guitar amplifiers is sweeter and the guitarist can create far more
classic
rock sound effects with tube amps than with solid state amplifiers. Like
with the home audio amplifiers, a lot depends on the push-pull output
tubes
being balanced. Having balanced output tubes is essential to getting the
most from your guitar amplifier.

Testing transmitter tubes is another application for a tube curve tracer.

Dennis Tillman W7PF

-----Original Message-----
From: Richard Solomon
Sent: Sunday, January 05, 2020 9:22 AM
Subject: Re: [TekScopes] Tektronix 570 Vacuum Tube Curve Tracer on eBay

Pardon me if this sounds like
Heresy, but what real world use
would have for one of these ?

I can see the "cool/nostalgia"
factor, but other than that, what
would one do with it ??

Thanks, Dick, W1KSZ

On Sun, Jan 5, 2020 at 8:32 AM Dave Daniel <kc0wjn@...> wrote:

I have been looking at sales of Tektronix 570s, mostly but not all on
ebay, for a long time now. All of then have had an asking price of
around $4k.

DaveD

Sent from a small flat thingy

On Jan 5, 2020, at 09:45, Eric <ericsp@...> wrote:

I would love to have a 570 in the lab but not for that that is nuts.


On 1/5/2020 9:36 AM, Mlynch001 wrote:
On Sat, Jan 4, 2020 at 10:48 PM, Dan Cordova wrote:

For less than $200, I put together a Dennis Tillman VTCT board,
and
modified
my Hickok Tube Tester to use with my Tektronix 575 curve tracer.
I
also made
the Daniel Schoo designed triode and pentode adapters for the
Tektronix 576
Curve Tracer at work.
I'm also not sure all my tubes and stereo gear are worth ~$4000
all
together.
;)
I KNOW my stereo gear is not worth that much! I have the stuff to
build Dennis Tillman's VTCT and I have a 576 as well. So even after I
buy a suitable tube tester, I am sure that all told I would have less
than
$1000 in the whole thing. It might not do what the 570 will do, but
likely 95% as much and still test solid state devices as well. You
would need to have a serious desire or even more serious need for this
thing in order to justify paying that price. From the description, it
sounds as though this thing is not quite ready to go as it is. The
elephant in the room is getting it shipped to ones location without it
being destroyed in the process. The seller does have a "Make an
Offer" option as well. This will be interesting to watch.









--
Dennis Tillman W7PF
TekScopes Moderator






Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

peter bunge
 

I had a University EE Summer Student who did not know how a tube worked so
I broke a 6SN7 and showed him the parts. He then said tubes were no longer
used so I asked him what he thought was in our 100kW RF amp that drove the
Superconducting Cyclotron, and how he would replace it with Solid State. I
then told him his theories MIGHT work but how would Solid State handle the
huge reflected power often sent back to the amplifier, and survive?
I'm not sure how I would test a 4CW200,000 (if I remember the 200kW water
cooled tube number correctly). The HV power supply was bigger than our
kitchen.

On Sun, Jan 5, 2020 at 4:01 PM Dennis Tillman W7PF <@Dennis_Tillman_W7pF>
wrote:

Hi Richard,

It may seem that vacuum tubes are history but nothing could be further
from the truth. To my amazement I have sold almost 200 of my little VTCT
Adapter boards. That really surprised me. That gives people a way to avoid
paying $5,000 for a 570 Tube Tester. It still costs at least a few hundred
dollars with my adapter because you still need some kind of transistor
curve tracer and a tube tester.

There are many applications that use tubes these days. Vacuum tube
manufacturing never went away and now the Russians are producing a lot of
them. But there are many other companies also doing it. A top of the line
vacuum tube audio amplifier will set you back $100,000 and eventually the
push-pull output tubes will need balancing or replacing. Likewise, rock
guitarists all use tube amplifiers, not solid state. The sound of tube
guitar amplifiers is sweeter and the guitarist can create far more classic
rock sound effects with tube amps than with solid state amplifiers. Like
with the home audio amplifiers, a lot depends on the push-pull output tubes
being balanced. Having balanced output tubes is essential to getting the
most from your guitar amplifier.

Testing transmitter tubes is another application for a tube curve tracer.

Dennis Tillman W7PF

-----Original Message-----
From: Richard Solomon
Sent: Sunday, January 05, 2020 9:22 AM
Subject: Re: [TekScopes] Tektronix 570 Vacuum Tube Curve Tracer on eBay

Pardon me if this sounds like
Heresy, but what real world use
would have for one of these ?

I can see the "cool/nostalgia"
factor, but other than that, what
would one do with it ??

Thanks, Dick, W1KSZ

On Sun, Jan 5, 2020 at 8:32 AM Dave Daniel <kc0wjn@...> wrote:

I have been looking at sales of Tektronix 570s, mostly but not all on
ebay, for a long time now. All of then have had an asking price of
around $4k.

DaveD

Sent from a small flat thingy

On Jan 5, 2020, at 09:45, Eric <ericsp@...> wrote:

I would love to have a 570 in the lab but not for that that is nuts.


On 1/5/2020 9:36 AM, Mlynch001 wrote:
On Sat, Jan 4, 2020 at 10:48 PM, Dan Cordova wrote:

For less than $200, I put together a Dennis Tillman VTCT board,
and
modified
my Hickok Tube Tester to use with my Tektronix 575 curve tracer.
I
also made
the Daniel Schoo designed triode and pentode adapters for the
Tektronix 576
Curve Tracer at work.
I'm also not sure all my tubes and stereo gear are worth ~$4000
all
together.
;)
I KNOW my stereo gear is not worth that much! I have the stuff to
build Dennis Tillman's VTCT and I have a 576 as well. So even after I
buy a suitable tube tester, I am sure that all told I would have less
than
$1000 in the whole thing. It might not do what the 570 will do, but
likely 95% as much and still test solid state devices as well. You
would need to have a serious desire or even more serious need for this
thing in order to justify paying that price. From the description, it
sounds as though this thing is not quite ready to go as it is. The
elephant in the room is getting it shipped to ones location without it
being destroyed in the process. The seller does have a "Make an
Offer" option as well. This will be interesting to watch.









--
Dennis Tillman W7PF
TekScopes Moderator




Re: Trying to bring back a AA501

David DiGiacomo
 

On Sun, Jan 5, 2020 at 1:31 PM KB6NAX <gumbear@...> wrote:

Watch out! The CD and 74 pinouts are different. You don't what to hack up
your circuit board.
That is not correct. CD40175 and 74C175 have the same pinout.


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

 

Hi Greg,

That is less likely than you think. Almost since the beginning Tek has designed its circuitry using what is known as a "Long-Tailed Pair". One of the features of this circuit design is its high immunity to the parameter changes a tube undergoes as it ages. The circuit is stable until the tube is worn out. So you have no guarantee that a tube you pull out of a Tek scope will work. In addition there are so many people selling used tubes that there isn't much profit in it unless, like the eBay seller that was mentioned, he uses a 570 to match a pair of tubes and certifies that they meet the basic manufacturers specs for transconductance (gm), voltage gain (mu), and plate resistance (rp). That is a time consuming process requiring a very expensive tube tester. So this isn't a lucrative pastime.

Dennis Tillman W7PF

Here is an excerpt from Wikipedia describing the history and benefits of the "Long Tailed Pair":
The long-tailed pair was developed from earlier knowledge of push-pull circuit techniques and measurement bridges. An early circuit which closely resembles a long-tailed pair was published by British neurologist Bryan Matthews in 1934, and it seems likely that this was intended to be a true long-tailed pair but was published with a drawing error. The earliest definite long-tailed pair circuit appears in a patent submitted by Alan Blumlein in 1936. By the end of the 1930s the topology was well established and had been described by various authors including Frank Offner (1937), Otto Schmitt (1937) and Jan Friedrich Toennies (1938) and it was particularly used for detection and measurement of physiological impulses.

The long-tailed pair was very successfully used in early British computing, most notably the Pilot ACE model and descendants, Maurice Wilkes’ EDSAC, and probably others designed by people who worked with Blumlein or his peers. The long-tailed pair has many favorable attributes if used as a switch: largely immune to tube (transistor) variations (of great importance when machines contained 1,000 tubes or more), high gain, gain stability, high input impedance, medium/low output impedance, good clipper (with a not-too-long tail), non-inverting (EDSAC contained no inverters!) and large output voltage swings. One disadvantage is that the output voltage swing (typically ±10–20 V) was imposed upon a high DC voltage (200 V or so), requiring care in signal coupling, usually some form of wide-band DC coupling. Many computers of this time tried to avoid this problem by using only AC-coupled pulse logic, which made them very large and overly complex (ENIAC: 18,000 tubes for a 20 digit calculator) or unreliable. DC-coupled circuitry became the norm after the first generation of vacuum tube computers.

-----Original Message-----
From: Greg Muir
Sent: Sunday, January 05, 2020 9:44 AM
Subject: Re: [TekScopes] Tektronix 570 Vacuum Tube Curve Tracer on eBay

I'm sure that he probably has numerous Tek scopes and plugins in his back room missing all of their tubes. They will most likely be the next thing to show up on ePay.

Greg




--
Dennis Tillman W7PF
TekScopes Moderator


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

 

Hi Richard,

It may seem that vacuum tubes are history but nothing could be further from the truth. To my amazement I have sold almost 200 of my little VTCT Adapter boards. That really surprised me. That gives people a way to avoid paying $5,000 for a 570 Tube Tester. It still costs at least a few hundred dollars with my adapter because you still need some kind of transistor curve tracer and a tube tester.

There are many applications that use tubes these days. Vacuum tube manufacturing never went away and now the Russians are producing a lot of them. But there are many other companies also doing it. A top of the line vacuum tube audio amplifier will set you back $100,000 and eventually the push-pull output tubes will need balancing or replacing. Likewise, rock guitarists all use tube amplifiers, not solid state. The sound of tube guitar amplifiers is sweeter and the guitarist can create far more classic rock sound effects with tube amps than with solid state amplifiers. Like with the home audio amplifiers, a lot depends on the push-pull output tubes being balanced. Having balanced output tubes is essential to getting the most from your guitar amplifier.

Testing transmitter tubes is another application for a tube curve tracer.

Dennis Tillman W7PF

-----Original Message-----
From: Richard Solomon
Sent: Sunday, January 05, 2020 9:22 AM
Subject: Re: [TekScopes] Tektronix 570 Vacuum Tube Curve Tracer on eBay

Pardon me if this sounds like
Heresy, but what real world use
would have for one of these ?

I can see the "cool/nostalgia"
factor, but other than that, what
would one do with it ??

Thanks, Dick, W1KSZ

On Sun, Jan 5, 2020 at 8:32 AM Dave Daniel <kc0wjn@...> wrote:

I have been looking at sales of Tektronix 570s, mostly but not all on
ebay, for a long time now. All of then have had an asking price of
around $4k.

DaveD

Sent from a small flat thingy

On Jan 5, 2020, at 09:45, Eric <ericsp@...> wrote:

I would love to have a 570 in the lab but not for that that is nuts.


On 1/5/2020 9:36 AM, Mlynch001 wrote:
On Sat, Jan 4, 2020 at 10:48 PM, Dan Cordova wrote:

For less than $200, I put together a Dennis Tillman VTCT board,
and
modified
my Hickok Tube Tester to use with my Tektronix 575 curve tracer.
I
also made
the Daniel Schoo designed triode and pentode adapters for the
Tektronix 576
Curve Tracer at work.
I'm also not sure all my tubes and stereo gear are worth ~$4000
all
together.
;)
I KNOW my stereo gear is not worth that much! I have the stuff to
build Dennis Tillman's VTCT and I have a 576 as well. So even after I
buy a suitable tube tester, I am sure that all told I would have less
than
$1000 in the whole thing. It might not do what the 570 will do, but
likely 95% as much and still test solid state devices as well. You
would need to have a serious desire or even more serious need for this
thing in order to justify paying that price. From the description, it
sounds as though this thing is not quite ready to go as it is. The
elephant in the room is getting it shipped to ones location without it
being destroyed in the process. The seller does have a "Make an
Offer" option as well. This will be interesting to watch.









--
Dennis Tillman W7PF
TekScopes Moderator


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

 

Hi Eric,
Now that you mention it Tek had something like this. It is in the 1994 catalog on pages 414 and 415. It is called the Semiconductor Workbench. I just came across it for the first time and read the description last night. It seems like a very odd way to do things but who am I to say. I don't think it was in the catalogs for a very long time (just a guess). That would suggest there was little demand for it.

Since you mentioned Fluke did this too maybe Tek OEM'd the Fluke unit and put their name on it. Tek has bought other things from Fluke. They both have excellent engineering teams. They would both become even closer in 2007 when Danaher buys them both.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Eric
Sent: Sunday, January 05, 2020 9:08 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tektronix 570 Vacuum Tube Curve Tracer on eBay

SMU is source measure unit. From the KB i saw from Keithley there is a way to do curve tracing with the 2461 and the 2471. It requires 2 units at $9,600 each an interconnecting cable cat 5 on each out to a computer which has the Keithley lab suite software. I think the setup is one SMU for collector voltage and the other controls base current. The units sweep some set points then the software plots and excel style graph from the measured points. There was a KB that Keithley put out on how to set everything up I will see if i can dig it up.

On 1/5/2020 10:51 AM, peter bunge wrote:
So what is a SMU?

SMU Singapore Management University
SMU Southern Methodist University
SMU Saint Mary's University *(Halifax, Nova Scotia; Philippines)* SMU
Solid (Waste) Management Unit SMU Saint Mary's University of Minnesota
SMU Sikkim Manipal University *(India)* SMU Suomen Merimies-Unioni
*(Finnish: Finnish Seamen's Union)* SMU Sindicato Médico del Uruguay
SMU Storage Migrator for Unix SMU Shanghai Maritime University
*(Shanghia, China)* SMU Santa Monica United *(soccer; California)* SMU
Swansea Metropolitan University *(UK)* SMU Sekolah Menengah Umum
*(Indonesian High school)* SMU Special Management Unit SMU Services
Médicaux d'Urgence *(French: Emergency Medical Services)* SMU Southern
Mississippi University SMU Special Mission Unit *(US DoD)* SMU System
Management Utility SMU Smallest Mining Unit SMU Start Me Up SMU
Southeastern Massachusetts University *(formerly used, now Umass)* SMU
Source Measurement Unit SMU Storage Management Utility *(data
storage)* SMU Special Make Up SMU Selective Mining Unit SMU Sociedad
Mexicana de Urología SMU System Managed Undo *(Oracle Databases)* SMU
Sediment Management Unit SMU Supply Management Unit SMU Sassy
Management Unit SMU Small Marching Unit SMU Switch Multiplexer Unit
SMU Secure Mobile Unit SMU Service Meter Unit SMU Scrutin Majoritaire
Uninominal *(French: Single Member Plurality)* SMU Service Management
Unit SMU Strategic Market Unit SMU Switch Multiplex Unit SMU Svenska
Missionskyrkans Ungdomsförbund *(Swedish Christian Youth
Organisation)* SMU Storage Management Unit SMU Secours Médical
d'Urgence
*(French: Emergency Medical Relief; various organizations)* SMU
Subscriber Module Urban SMU Single-Word, Multiple-Bit Upset SMU
Software Maintenance Update *(Cisco)* SMU Speaker/Microphone Unit *(US
NASA)* SMU System Master Unit SMU Sindh Madressah University
*(Karachi, Pakistan)* SMU Shelter Management Unit *(US FEMA)* SMU
Space Management Utility SMU Small and Medium-Sized Undertaking SMU
System Measurement Unit SMU Simple Mail Users SMU Space Self
Maneuvering Unit SMU Secours Mondial d'Urgence *(French: World
Emergency Relief)* SMU Super Module Unit SMU Super Millionaire
University *(fictional, from TV show Gilligan's Island)* SMU Smoke Me
Up SMU Safe Mode Utility SMU Special Maintenance Unit *(India)*

On Sun, Jan 5, 2020 at 10:10 AM Eric <ericsp@...> wrote:

Is there a modern version of these curve tracers? From what I have
seen the 300 series seems to be about the top end. I know you can get
the same functionality today but you need 2 X $10,000 SMU's, and a
computer, and software so call it a $25,000 setup though given the
catalog price of the 576 and the 300's doesn't sound so bad now that I say it.


On 1/5/2020 6:59 AM, cnc_joker via Groups.Io wrote:
A long time ago in the early 80's the Massachusetts hams ran an
auction
at Honeywell Inc
in Billerica. You could bring your old electronic stuff and they would
auction it off. It was
great fun and always well attended.

Anyway, one guy brought a 370 to be auctioned. As he wheeled it in on
a cart the crowd
chuckled. When it went up for auction it sold for $1 and the
auctioneer had a hard time
getting even that! Between then and now, what a great return on that
investment.
Pete.









--
Dennis Tillman W7PF
TekScopes Moderator


Re: Logic families

Mlynch001
 

Arden,

You are correct. I have an extensive catalog of older documents and catalogs. I find the posts that I read something of a study starter. This gives me a starting point, then I dig into the catalogs and data sheets and find out about a particular chip or other component. When I find a new or different document or catalog, I download it to my archive. You cannot have too much information.

Thanks!

--
Michael Lynch
Dardanelle, AR


Re: Trying to bring back a AA501

KB6NAX
 

Watch out! The CD and 74 pinouts are different. You don't what to hack up your circuit board.

Also, be advised, when troubleshooting IC's in general having the schematic of the device gives understanding of how inputs and outputs work. For example a tri-state output could be "off" and not "open." A CMOS input is high impedance so you don't know if the input stage is blown unless a clamp diode is shorted. The ultimate is to try the truth table, a lot of work on complex parts. Parts substitution can't be beat for getting results. I always buy two or more when in that situation.

eBay to the rescue - Item #372418190226

Arden

-----Original Message-----
From: Eric
Sent: Sunday, January 05, 2020 6:51 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Trying to bring back a AA501

I did find out that the AA501 does need the VCC of 15V so the HC series
logic is out for sure. I am going to order some of the direct
replacement parts as there is a supply house that has then mouser and
digikey were out. Texas Instrument cross reference says a CD40175BE is a
comparable part as well. I have also confirmed the fault as with this IC
out of circuit the 501 says 100+% distortion on all frequencies also one
of the outputs is open when i check it with my small curve tracer. On
this one pin 14 is dead.


On 1/5/2020 1:08 AM, KeepIt SimpleStupid via Groups.Io wrote:
My GOTO place has it: http://www.utsource.net/sch/MM74C175N
On Saturday, January 4, 2020, 10:31:47 PM EST, Mlynch001 <@mlynch001> wrote:
OK, learned something. LSTTL and TTL are different animals? SN74HC175N Will drive 10 outputs of LSTTL. Just trying to learn how logic works, I will likely encounter a similar issue in the future.

Thanks!


Re: Logic families

KB6NAX
 

Hi Mike,

99% of what I know about IC's and logic families is from reading the detailed information in data books. Keep looking for older data books to add to your library. It will enhance your practical knowledge way better than reading bits and pieces on the web.

Arden

-----Original Message-----
From: Mlynch001
Sent: Sunday, January 05, 2020 2:51 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Logic families

Arden,

True. However, in the context of much of the equipment that many of us are dealing with, these older forms of logic are most relevant. This is why I read and try to understand posts, such as Eric’s. So the historical part is nice to know. But understanding how the early forms work is essential to the understanding of the later versions. That is why I enjoy herring from people, such as yourself, and others on this forum who have a better understanding of the subject.

Thank you
--
Michael Lynch
Dardanelle, AR


Re: Tektronix 2465 for sale ...

rskrishnan@...
 

Ah that makes sense!
I saw the POST fail and also saw the horiz sweep was dead and thought the POST was complaining about that.
So then we have hybrid trigger problems -and- a dead horiz sweep.
If there is any brave soul that wants to dive into this please send me a message.


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Geoffrey Thomas
 

Oooh! Heresy. Careful...

On 05/01/2020 17:56, george edmonds via Groups.Io wrote:
Hi
You hit in in one, Audio nuts, they can tell the shape of the getter in the valves/tubes in an audio amp by just listening to the wider deeper sound produced by the "correct" shaped getter. There is no fool like an Audio fool and they appear to have very deep pockets.
73 George G6HIG
On Sunday, 5 January 2020, 17:29:00 GMT, Jamie Ostrowski <jamie.ostrowski@...> wrote:
Tube traders and audio nuts use them for sure - especially for tube
matching.


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Greg Muir
 

A sidebar – it is little known as to the vacuum tube equipment still possessed by the military for use when EMP from a nuclear blast renders a portion of the solid-state hardware useless. EMP hardening of a lot of the newer equipment has reduced this inventory but some still remains. Hopefully we will never have to use the former and hope the latter will still work if it does happen. But at that time I will be occupied by other issues of my own concern and won’t be too worried about if our military can communicate.

Greg


Re: 465M Junker

KB6NAX
 

That was the problem I had with the modules in the 475. I gave the modules to an experienced assembler who worked on surface mount boards and had a soldering iron that could reach inside and reflow the joints. But unfortunately the assembler had no experience doing that kind of rework and failed to repair the modules. I had to move on.

Arden

-----Original Message-----
From: tekscopegroup@...
Sent: Sunday, January 05, 2020 8:59 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] 465M Junker

On Fri, Jan 3, 2020 at 05:41 PM, KB6NAX wrote:
.... After fussing and fuming I
removed the shield from the ch 1 attenuator switch and spotted a possible
source of the problem. Some years ago I gave up on a 475 which had several
faulty attenuator plug-in modules. The 465M has two in each channel. I
worked them up and down in their sockets a few times and seemingly made a
reduction in the erratic behavior. But being a glutton for punishment I
wasn't going to give up yet. Just moving the scope around caused dramatic
changes in the chaos displayed on the CRT. And then suddenly it would stop,
I'd get nice noise free traces. Then it would start up again. .........
I encountered a very similar problem on a 2213A, in which the attenuation modules are also plugin type and it has two on each channel. The levels where all over the place but sometimes things seemed to settle after unplugging and plugging the modules several times or wedge them with some foam squares against the metal top covers to immobilize etc. But then the problem would invariably always return in short order. It looked like a bad contact on the pins of the modules or that the contact fingers on the receiving board where perhaps stretched or loose. But in the end it turned out to be a cold solder joint at one of the pins right inside one of the attenuation modules. In the end opened all four modules and carefully reflowed the solder joints on the pins and all problems where gone for good. There where at least one or more really poor looking solder joints inside each module. The thread I opened about this is somewhere here among the group messages.
............


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Dan Cordova <danny_cordov@...>
 

I really doubt that people who have money to buy a $4,000 conversation piece use eBay, let alone would know how to turn the curve tracer on and use it and do anything with tubes.

On Sunday, January 5, 2020, 10:59:13 AM PST, John Williams <books4you@...> wrote:

The real use was for quite advanced vacuum tube circuit design. Today there just isn’t much  of that going on, sad to say. But one would make a nice conversation piece in the living room I guess. It would be a really good tube tester. But beyond that even I cannot see much use.


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

John Williams
 

The real use was for quite advanced vacuum tube circuit design. Today there just isn’t much of that going on, sad to say. But one would make a nice conversation piece in the living room I guess. It would be a really good tube tester. But beyond that even I cannot see much use.


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

george edmonds
 

Hi

You hit in in one, Audio nuts, they can tell the shape of the getter in the valves/tubes in an audio amp by just listening to the wider deeper sound produced by the "correct" shaped getter. There is no fool like an Audio fool and they appear to have very deep pockets.

73 George G6HIG

On Sunday, 5 January 2020, 17:29:00 GMT, Jamie Ostrowski <jamie.ostrowski@...> wrote:

Tube traders and audio nuts use them for sure - especially for tube
matching.





On Sun, Jan 5, 2020 at 11:22 AM Richard Solomon <dickw1ksz@...> wrote:

Pardon me if this sounds like
Heresy, but what real world use
would have for one of these ?

I can see the "cool/nostalgia"
factor, but other than that, what
would one do with it ??

Thanks, Dick, W1KSZ

On Sun, Jan 5, 2020 at 8:32 AM Dave Daniel <kc0wjn@...> wrote:

I have been looking at sales of Tektronix 570s, mostly but not all on
ebay, for a long time now. All of then have had an asking price of around
$4k.

DaveD

Sent from a small flat thingy

On Jan 5, 2020, at 09:45, Eric <ericsp@...> wrote:

I would love to have a 570 in the lab but not for that that is nuts.


On 1/5/2020 9:36 AM, Mlynch001 wrote:
On Sat, Jan  4, 2020 at 10:48 PM, Dan Cordova wrote:

  For less than $200, I put together a Dennis Tillman VTCT board, and
modified
my Hickok Tube Tester to use with my Tektronix 575 curve tracer.  I
also made
the Daniel Schoo designed triode and pentode adapters for the
Tektronix 576
Curve Tracer at work.
I'm also not sure all my tubes and stereo gear are worth ~$4000 all
together.
    ;)
I KNOW my stereo gear is not worth that much!  I have the stuff to
build Dennis Tillman's VTCT and I have a 576 as well.  So even after I
buy
a suitable tube tester, I am sure that all told I would have less than
$1000 in the whole thing.  It might not do what the 570 will do, but
likely
95% as much and still test solid state devices as well.  You would need
to
have a serious desire or even more serious need for this thing in order
to
justify paying that price.  From the description, it sounds as though
this
thing is not quite ready to go as it is.  The elephant in the room is
getting it shipped to ones location without it being destroyed in the
process.  The seller does have a "Make an Offer" option as well.  This
will
be interesting to watch.








Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Greg Muir
 

I'm sure that he probably has numerous Tek scopes and plugins in his back room missing all of their tubes. They will most likely be the next thing to show up on ePay.

Greg


Re: Tektronix 570 Vacuum Tube Curve Tracer on eBay

Jamie Ostrowski
 

Tube traders and audio nuts use them for sure - especially for tube
matching.

On Sun, Jan 5, 2020 at 11:22 AM Richard Solomon <dickw1ksz@...> wrote:

Pardon me if this sounds like
Heresy, but what real world use
would have for one of these ?

I can see the "cool/nostalgia"
factor, but other than that, what
would one do with it ??

Thanks, Dick, W1KSZ

On Sun, Jan 5, 2020 at 8:32 AM Dave Daniel <kc0wjn@...> wrote:

I have been looking at sales of Tektronix 570s, mostly but not all on
ebay, for a long time now. All of then have had an asking price of around
$4k.

DaveD

Sent from a small flat thingy

On Jan 5, 2020, at 09:45, Eric <ericsp@...> wrote:

I would love to have a 570 in the lab but not for that that is nuts.


On 1/5/2020 9:36 AM, Mlynch001 wrote:
On Sat, Jan 4, 2020 at 10:48 PM, Dan Cordova wrote:

For less than $200, I put together a Dennis Tillman VTCT board, and
modified
my Hickok Tube Tester to use with my Tektronix 575 curve tracer. I
also made
the Daniel Schoo designed triode and pentode adapters for the
Tektronix 576
Curve Tracer at work.
I'm also not sure all my tubes and stereo gear are worth ~$4000 all
together.
;)
I KNOW my stereo gear is not worth that much! I have the stuff to
build Dennis Tillman's VTCT and I have a 576 as well. So even after I
buy
a suitable tube tester, I am sure that all told I would have less than
$1000 in the whole thing. It might not do what the 570 will do, but
likely
95% as much and still test solid state devices as well. You would need
to
have a serious desire or even more serious need for this thing in order
to
justify paying that price. From the description, it sounds as though
this
thing is not quite ready to go as it is. The elephant in the room is
getting it shipped to ones location without it being destroyed in the
process. The seller does have a "Make an Offer" option as well. This
will
be interesting to watch.