Date   

Re: Looking for 366 1280 00 (trig level knob for 465B)

Jan Weber
 

Hi Doug,

I have one of these, see the picture in the "465knob" gallery on the
TekScopes group.io page. I'm located in Germany.

Regards

Jan


Doug Gordon <dmgordon@pacbell.net> schrieb am Fr., 9. Okt. 2020, 22:18:

Hi,
Have tried Sphere and Qservice with no luck. Hoping someone here has a
lead.
Thanks.
Doug Gordon


Sent from Mail for Windows 10



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Re: 'Tektronix Short Destroyer'

Michael A. Terrell
 

I know that Microdyne sued, and won against Scientific-Atlanta for cloning
one of our products. Their design replaced the LED displays with a large
flat screen, but the actual circuits were copied from a receiver and maual
they bought directly from Microdyne. I agree about early transistors. Some
were barely good at audio frequencies. Hank Lin was one of the founders of
Microdyne. He sold all his stock to L3 around 1999/2000. He had controlling
interest. Telemetry is a tiny market, and I'm certain that employees
drifted from one company to another. L3 bought Microdyne after wasting
$1,000,000 trying to develop a digital receiving system. We got the
'prototype' after the purchase. It was the cabinet for the design, with an
old laptop inside to mimic the controls. It was too light, so the
'engineer' had wedged a heavy roll of ribbon cable under the laptop.
Microdyne also built and sold some test equipment for Telemetry. The
TSS2000 was in production in the late '90s. I have possibly the only
surviving Microdyne C-band signal generator. They built a handful of them
for final test. They all went into a dumpster when they abandoned Satellite
TV products. A tech had grabbed this one. He gave it to me, about 20 years
ago.

On Mon, Oct 12, 2020 at 12:26 AM Chuck Harris <cfharris@erols.com> wrote:

I would have thought DEI and TR711 would have done it for anyone
familiar with the company, but yes, it was Defense Electronics, Inc..

I worked there in 1972, when I was a high school student.

DEI came from Nems-Clarke and Vitro in some way, which is where the
tube receivers came from. The TR711, itself, was entirely solid state,
but there was the odd nuvistor, or WE coaxial triode, in some of the
external preamps, and front end assemblies. Along with a lot of
Mallory inductatuners. Transistors weren't all that good at RF in
1972.

There was tremendous inbreeding between Nems-Clarke, Vitro, DEI, CEI,
WJ, ACL, and apparently Microdyne. Many of them were routinely suing
each other for infringement of this, or that, patent.

After DEI, the telemetry receiver, company folded in 1972 or 73; DEI
continued on as a studio making Hollywood movies for another decade,
or so.

When they found out I was a ham, they kept giving me all sorts of
stuff.

-Chuck Harris

Michael A. Terrell wrote:
A bit off topic, but are you talking Defense Electronics, Incorporated? A
couple engineers and a salesman from there designed and built the first
Microdyne Telemetry receiver in their garage. That frequency range
covered
the Instrumentation data recorders. They output a 70 MHz center
frequency.
They recorded the 70MHz IF output for later use, as well as keeping
records
on tests. Typically, minr data channels were looked at on individual
channels after a test, to prevent the need for multiple receivers. I had
a
pile of DEI manuals. Everything gwas tube based. The Microdyne products
were all Solid State. Their early products were all 1100 series. They
were
large, but they could be paired with a combiner to do diversity
reception.
The 1200, 1400, 700 and 1620 series were in production when I went to
work
there. They were followed by the RCB2000, the first SDR based dual
receiver
with a digital video combiner. That was the last project that I was
involved with.

On Sat, Oct 10, 2020 at 10:59 AM Chuck Harris <cfharris@erols.com>
wrote:

When I worked for DEI towards their end, there were some curious
TR711 telemetry receivers that had tuners that went from 50 to 110MHz,
and had stereo multiplex discriminator plugins. They were on the
factory floor, but they weren't where they should be, but rather
were sitting on carts out of the way up against a wall.

I never knew what the real story was on them, but...

-Chuck Harris

greenboxmaven via groups.io wrote:
Collins was also very helpful to employees who wanted to build for
themselves at home
what they built in the factory. At least one person bought the parts
over time and
assembled their own 75A4 receiver. Such things are probably
unthinkable
with today's
business model, but the benefits in workforce morale and skill are
irreplaceable. As
far as instrumentation companies building audio gear, Non Linear
Systems
built and
sold stereo receivers for a while, and Rhode & Schwarz built many
models
of
communications receivers and some excellent FM stereo tuners.

Bruce Gentry, KA2IVY


On 10/10/20 9:17 AM, Chuck Harris wrote:
Tektronix employees made lots of special equipment to make their
jobs in manufacturing, testing and repair easier.

And, tektronix most certainly did make a variety of instruments
that were involved in audio, including amplifiers, low distortion
signal generators, and distortion analyzers.

This item is very likely made for use on the factory floor at
tektronix.

Further, like HP, tektronix made their supply room available to
employees for off the books projects using tektronix cabinets,
etc..

-Chuck Harris

Tim Phillips wrote:
From Tim P (UK)
ebay: 193462625382

Even has a Tek cal sticker on it. I suspect the only thing 'Tek'
about
it
is the case.
No internal shots either. Anyway Tektronix never got into audio gear
??

curiouser and .......

Tim


























Re: 11801A NVRAM-type error, but no Smart Sockets to be found? Real batteries instead

Albert Otten
 

Christian,

It seems you looked at the wrong boards to find the battery sockets and found the batteries BTxxx. In both the earliest (11801) and latest (CSA803C) pdf service manuals the ICs with battery sockets are U500 and U511 at A5 Timing Base/Controller board. In my CSA803 and CSA803A it's the same. I can't be sure of the 11801A but I expect it to be the same then.

Albert

On Mon, Oct 12, 2020 at 03:09 AM, Christian wrote:


Hi all,

My name is Christian and I have a test equipment problem.

I have a new-to-me 11801A that has the standard boot diagnostic NVRAM error.
I'm all ready to go in and pull the Smart Sockets and figure out the RAM
timing and get new memory from Maxim, and them I find that I -have- no Smart
Sockets at all. I -do- have two boards with cylindrical lithium batteries
(both measuring 3.0ish volts). I have not been able to find the 'A' specific
diagnostic manual so I'm more than a bit at sea. Any help would be greatly
appreciated - this machine came with 4x SD-24's and my fast diff pulse gen is
on the way; I have signal paths to debug soon!


Re: Tektronix 465 vertical instability problem.

Göran Krusell
 

yes, I have. I had a poor connection from vertical board differential output to
the pins on the CRT, loose cables.
Göran


Re: Tektronix 2465A noise on readout

Jean-Paul
 

Gregor, bravo!

I would Suspect all lytics on LV side of HV PS, and any tants if present.

Check the DC supplies for HF ripple at the entrance of the HV PS PCB.

Note The schematics may vary with serial number series.

Bon Chance,

Jon


Re: Tek 7854 intermittent issues

Nick Corvid
 

Okay, while checking the aux board before I stuck it back in I noticed that C92 has a much lower resistance than I expected, only about 150 ohms with no increase like you might expect when held, this could be a byproduct of me having to test in situ since I don't have access to my iron right now but even still it seems off.


Re: Tek 7854 intermittent issues

Nick Corvid
 

Alright, sorry for the delay.

I checked the auxiliary regulator board and couldn't see anything immediately wrong with any components on it. Picture of the board: https://groups.io/g/TekScopes/photo/252782/0?p=Created,,,20,2,0,0

After that I tried David's suggestion and ran the scope with no digital boards installed. For those curious to its behavior with no boards installed, it started in a broken analog mode with no triggering with strange gaps in the trace, with all panel lights illuminated but the left button and LEDs.
Trace with gaps: https://groups.io/g/TekScopes/photo/252782/2?p=Created,,,20,2,0,0
Front panel: https://groups.io/g/TekScopes/photo/252782/1?p=Created,,,20,2,0,0

Additionally it would occasionally loose the trace with no obvious reason while I was making measurements.

With no boards in I checked the -5 Volt and found with the same voltage settings a significantly different trace with reduced ripple. https://groups.io/g/TekScopes/photo/252782/3?p=Created,,,20,2,0,0

Not super sure where to look from here.


Re: 'Tektronix Short Destroyer'

Chuck Harris <cfharris@...>
 

I would have thought DEI and TR711 would have done it for anyone
familiar with the company, but yes, it was Defense Electronics, Inc..

I worked there in 1972, when I was a high school student.

DEI came from Nems-Clarke and Vitro in some way, which is where the
tube receivers came from. The TR711, itself, was entirely solid state,
but there was the odd nuvistor, or WE coaxial triode, in some of the
external preamps, and front end assemblies. Along with a lot of
Mallory inductatuners. Transistors weren't all that good at RF in
1972.

There was tremendous inbreeding between Nems-Clarke, Vitro, DEI, CEI,
WJ, ACL, and apparently Microdyne. Many of them were routinely suing
each other for infringement of this, or that, patent.

After DEI, the telemetry receiver, company folded in 1972 or 73; DEI
continued on as a studio making Hollywood movies for another decade,
or so.

When they found out I was a ham, they kept giving me all sorts of
stuff.

-Chuck Harris

Michael A. Terrell wrote:

A bit off topic, but are you talking Defense Electronics, Incorporated? A
couple engineers and a salesman from there designed and built the first
Microdyne Telemetry receiver in their garage. That frequency range covered
the Instrumentation data recorders. They output a 70 MHz center frequency.
They recorded the 70MHz IF output for later use, as well as keeping records
on tests. Typically, minr data channels were looked at on individual
channels after a test, to prevent the need for multiple receivers. I had a
pile of DEI manuals. Everything gwas tube based. The Microdyne products
were all Solid State. Their early products were all 1100 series. They were
large, but they could be paired with a combiner to do diversity reception.
The 1200, 1400, 700 and 1620 series were in production when I went to work
there. They were followed by the RCB2000, the first SDR based dual receiver
with a digital video combiner. That was the last project that I was
involved with.

On Sat, Oct 10, 2020 at 10:59 AM Chuck Harris <cfharris@erols.com> wrote:

When I worked for DEI towards their end, there were some curious
TR711 telemetry receivers that had tuners that went from 50 to 110MHz,
and had stereo multiplex discriminator plugins. They were on the
factory floor, but they weren't where they should be, but rather
were sitting on carts out of the way up against a wall.

I never knew what the real story was on them, but...

-Chuck Harris

greenboxmaven via groups.io wrote:
Collins was also very helpful to employees who wanted to build for
themselves at home
what they built in the factory. At least one person bought the parts
over time and
assembled their own 75A4 receiver. Such things are probably unthinkable
with today's
business model, but the benefits in workforce morale and skill are
irreplaceable. As
far as instrumentation companies building audio gear, Non Linear Systems
built and
sold stereo receivers for a while, and Rhode & Schwarz built many models
of
communications receivers and some excellent FM stereo tuners.

Bruce Gentry, KA2IVY


On 10/10/20 9:17 AM, Chuck Harris wrote:
Tektronix employees made lots of special equipment to make their
jobs in manufacturing, testing and repair easier.

And, tektronix most certainly did make a variety of instruments
that were involved in audio, including amplifiers, low distortion
signal generators, and distortion analyzers.

This item is very likely made for use on the factory floor at
tektronix.

Further, like HP, tektronix made their supply room available to
employees for off the books projects using tektronix cabinets,
etc..

-Chuck Harris

Tim Phillips wrote:
From Tim P (UK)
ebay: 193462625382

Even has a Tek cal sticker on it. I suspect the only thing 'Tek' about
it
is the case.
No internal shots either. Anyway Tektronix never got into audio gear ??

curiouser and .......

Tim






















Re: 11801A NVRAM-type error, but no Smart Sockets to be found? Real batteries instead

 

For the two 32kx8 NVRAM chips that are in the battery backed socket, I use these and they work fine. Remove the battery socket and ram chip and just install these devices. You will need to power up and initialize the scope several times to get the Rams programed.

https://www.mouser.com/ProductDetail/511-M48Z3570PC1

Cheap and in stock last I checked.

Regards,

Tom

On 10/8/2020 12:02 PM, Christian via groups.io wrote:
Hi all,

My name is Christian and I have a test equipment problem.

I have a new-to-me 11801A that has the standard boot diagnostic NVRAM error. I'm all ready to go in and pull the Smart Sockets and figure out the RAM timing and get new memory from Maxim, and them I find that I -have- no Smart Sockets at all. I -do- have two boards with cylindrical lithium batteries (both measuring 3.0ish volts). I have not been able to find the 'A' specific diagnostic manual so I'm more than a bit at sea. Any help would be greatly appreciated - this machine came with 4x SD-24's and my fast diff pulse gen is on the way; I have signal paths to debug soon!



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Where was the 567/6R1 used?

snapdiode
 

Well, at AT&T in 1965 for one.

https://youtu.be/tziav_yq5_g?t=994


Re: Fun with 7000 series readouts

dabono@...
 

So, the readout system "knows" that 100 uA = 0.1 mA and displays it that way? If so, that's pretty cool.

I recently had to dive into the 7xxx readout system. One of the channels on one of the vertical bays of my 7603 was producing wonky readouts. By swapping the plugins around, I was able to tell the problem was in the mainframe itself (not the plugin). Then by comparing the expected row/column values for each time slot position to the actual readout, it's possible to isolate which row/column is bad.

It was a fun bit of detective work, and I (eventually) learned how the readout system works. It's a pretty clever piece of engineering!


Tektronix 465 (original model I think) Recap List

ctho.admin@...
 

If I am going to recap my Tektronix 465 scope, does anyone have a list of the usual suspects, offending electrolitic capacitors, which absolutely have to go, because they are a common point of failure? Not forgetting I suppose, the tantalum beads most likely to explode? Gonna try and get Nitchecons...

Tim


Tektronix 465 vertical instability problem.

ctho.admin@...
 

I'm seeing a problem with my Tektronix 465 where on initial power up, the trace starts off stable, but after a few minutes starts to "dance" up and down the screen. If I change the vertical setting, it quietens it down, for a while, but then starts to display the same problem. I'm going to open the bonnet, and clean all the rotary switches with IPA or deoxit where possible. Has anyone seen this kind of problem before, and have any advice as to what might be causing it, and what to do about it?

Tim


11801A NVRAM-type error, but no Smart Sockets to be found? Real batteries instead

Christian
 

Hi all,

My name is Christian and I have a test equipment problem.

I have a new-to-me 11801A that has the standard boot diagnostic NVRAM error. I'm all ready to go in and pull the Smart Sockets and figure out the RAM timing and get new memory from Maxim, and them I find that I -have- no Smart Sockets at all. I -do- have two boards with cylindrical lithium batteries (both measuring 3.0ish volts). I have not been able to find the 'A' specific diagnostic manual so I'm more than a bit at sea. Any help would be greatly appreciated - this machine came with 4x SD-24's and my fast diff pulse gen is on the way; I have signal paths to debug soon!


485 Power Supply Problems

hneal@...
 

I am trying to bring a 485 scope back to life and I've been trying to find a problem in the scope power supply. When turning on the scope, I get the dreaded "clicking". However, it will power up occasionally. When it is working, all voltages are dead on, and I get a trace on the CRT. I've checked the resistance of all the supplies and see no indications of shorted caps. If I look at TP1951 (BAL) with another scope, I see about a 700mV pulse during the startup time. If I ground TP1951 while the scope is trying to come up (clicking), it will usually start up, and again, all the voltages are correct. I can then remove the jumper, and the scope continues to run fine. I've followed Reed Dickinson's excellent checklist without finding any problems. I've noted that the -5V and -9V supplies seem to be slow in coming up when the scope is in clicking mode. (The fact that the Balance Node is going positive is an indication that a negative supply could be out.) In fact, they never get close to their correct values during the startup period. I've checked the tantalum caps in their regulator outputs and they are ok. I've also looked at the current sense (pin 13) of U1910 at it is staying below 0.5V. I've also tried swapping out U2072 and U2086, with no change noted.

I'm hoping someone here could give me some ideas of what to look for next.
Thanks.
Howard Neal


Re: Repairing a 577 that is pretty far gone.

Dave Casey
 

The 1826-0569 is an HP badged NE5534AT.
The 156-0200 is listed on eBay and also in stock at QService. Why not just
use the correct part?

Dave Casey

On Sun, Oct 11, 2020, 5:35 PM Eric <ericsp@gmail.com> wrote:

I got most of the repairs complete on a 577 that was pretty trashed I was
in to the calibration document to adjusting the vertical amp gain there was
very little adjustment. Holding in the beam find button and moving the
position know the trace moves up and down but also moves in a J pattern on
the crt when moving the vertical position control from clockwise to full
counter clockwise. I have tested all 4 transistors and all the resisters in
the vertical drive section and they all test with in spec however the amp
and drive transistors are VERY poorly matched when it comes to Hfe.
Troubleshooting lead me back to U570 which should be a tek 156-0200-00 (AKA
MC1456P) what was in the socket was a metal can labeled S 7939 1826 0569.
the unit is a very early one display serial number is B010114 the chassis
serial is B010124. Power supply checks out OK and is working. Any one know
what I can use in replacement of a 156-200?






Repairing a 577 that is pretty far gone.

Eric
 

I got most of the repairs complete on a 577 that was pretty trashed I was in to the calibration document to adjusting the vertical amp gain there was very little adjustment. Holding in the beam find button and moving the position know the trace moves up and down but also moves in a J pattern on the crt when moving the vertical position control from clockwise to full counter clockwise. I have tested all 4 transistors and all the resisters in the vertical drive section and they all test with in spec however the amp and drive transistors are VERY poorly matched when it comes to Hfe. Troubleshooting lead me back to U570 which should be a tek 156-0200-00 (AKA MC1456P) what was in the socket was a metal can labeled S 7939 1826 0569. the unit is a very early one display serial number is B010114 the chassis serial is B010124. Power supply checks out OK and is working. Any one know what I can use in replacement of a 156-200?


Re: Tektronix 2465A noise on readout

John Gord
 

Gregor,
How does the collector of Q1981 look compared to the waveform in the service manual? If that looks OK, I would check the grounding of all the paths around there, including the transformer, Q1981, and C1972. It sure looks like something has a damped high frequency ringing, pinged at the HV oscillator rate.
--John Gord

On Sat, Oct 10, 2020 at 11:31 PM, Gregor wrote:


I have some new findings! I jumped back to John's idea that it could be caused
by HV power supply. So I did the following test. I connected the CH1 input of
the oscilloscope to 100uF filter capacitor (C1972) on the HV power supply (I
connected nothing to the other channels).
And here is the result:
https://www.dropbox.com/s/th61anj5sho2m98/IMG_0737.jpg?dl=0
As you can see the HV oscillator is perfectly synchronous with the noise (I
should have done this test earlier).
So I know from my previous test, that C1972 isn't causing the problem therefor
I will dig deeper into the HV power supply. Any additional suggestions?

-Gregor


Re: Tektronix 2465A noise on readout

Gregor
 

I have some new findings! I jumped back to John's idea that it could be caused by HV power supply. So I did the following test. I connected the CH1 input of the oscilloscope to 100uF filter capacitor (C1972) on the HV power supply (I connected nothing to the other channels).
And here is the result:
https://www.dropbox.com/s/th61anj5sho2m98/IMG_0737.jpg?dl=0
As you can see the HV oscillator is perfectly synchronous with the noise (I should have done this test earlier).
So I know from my previous test, that C1972 isn't causing the problem therefor I will dig deeper into the HV power supply. Any additional suggestions?

-Gregor


Re: Looking for 366 1280 00 (trig level knob for 465B)

dabono@...
 

I don't have an exact replacement, but I can get one that's pretty close (my 465B also had a cracked trigger level knob). I don't know the part number, unfortunately.

The main difference is the one I used has a "skirt" at the base with a white dot indicator. The original is a straight taper, with a white line indicator on the side. But they both fit the same size shaft, and have the same size opening for the trigger slope knob.

PM me if interested and I can send a picture.

9501 - 9520 of 181537