Date   

Re: P7001 with 7704A (list of service manuals for P7001)

Ray Menke <rndmenke@...>
 

On Thu, Aug 22, 2002 at 01:53:51PM -0700, Miroslav Pokorni wrote:
Hello Ray,

Did you say 'core memory' in ' P7001 Core Memory Assembly 672-0057-00
Service'. I kind of new that there was nonvolotile storage in some scopes,
for example for front panel settings, but it never occured to me that core
memory would be used for that.
P7001 Core Memory Assembly 672-0057-00 Service
It has a core mat which is a planar stack of 20 mil cores arranged in
ten 64 X 64 arrays. The resulting pattern is a double herringbone, 3
wire-3D core stack. (10 bit 4096) Manual shows some neat photos of Read
and Strobe waveforms which are 40 nS wide.
This memory is used to store the information from the A-D converter.
The 4096 10 bit words, divided into eight sections. Four 512-word
blocks are available for waveform storage (Waveforms A, B, C, D), one
block is dedicated to scale-factor storage (ASCII format). The three
other 512 word blocks are available for computer generated messages,
which are limited to a maximum of 80 characters displayed at any one
time, due to space limitations on the CRT Screen.
Neat.. isn't it.
--
Ray Menke


Re: P7001 with 7704A (list of service manuals for P7001)

Ray Menke <rndmenke@...>
 

On Tue, Aug 20, 2002 at 10:13:09PM -0000, kngtron wrote:
Hi group !! I have a 7704A with a P7001 digitizer mid-frame. Does
anybody have a manual for service / operators / or programming for
it ?
I wandered out in my barn and found no less than 15 manuals! (Some have
notes on the schematics that our technician made when he attended the
factory training classes.) The stack is 4 inches high, and weighs less
than ten pounds.
Here is what they are (from 1974, '75, '76)
P7001 Power Supply Service
P7001 Core Memory Assembly 672-0057-00 Service
P7001 Sample and Hold 672-2382 circuit description, parts lists and
schematics
DPO Semiconductor Memory (Interim instruction manual)
P7001 DPO/CP Bus Interface 021-0116-00
P7001 Display Generator 670-2381-00
P7001 Digitizer Processor Service
DPO/4010-Family Interface concepts
P7001 Checkout Software Manual (Paper Tape and cassette) (No SW!)
P7001 Front Panel/Z Axis 670-2375-00 & 670-2380-00 service.
P7001 Main interface service
P7001 Readout Interface 670-2385-00
P7001 Semiconductor Memory 670-2981-00 & 670-3035-00 service
DPO System Specification and Calibration
(Contact me off the list to negotiate.) I thought perhaps the list would
appreciate what it took to service that little section in the middle.
Also, I seem to have some manualsin the barn on the PDP Computers and the
4010 bistable display that went with all that.
In the early 70's, each service center had one technician who would
specialize in the Digital Processing Oscillosope system and would often
troubleshoot at the customer's location. (They spent many weeks in
factory training classes!)

--
Ray Menke


Strange Interaction from a 7A13

jd_hurst <jdhurst@...>
 

I have a 7704a mainframe. In it, I normally use 7A26, 7A24, 7B85 and
7B80 plug-ins. That complement all works well.

Now, assuming I have a stable display when I am ready to turn the
machine off (i.e., 4 traces, readout on, medium fast sweep and auto
triggered), when I switch off, everything dies quickly and the screen
goes dark. Exactly what I expect.

I recently acquired a 7A13 differential comparator amplifier from
eBay, and other than the fact it must have been one of the first ones
made (*), it seems to work ok. The manual Vc coarse switch only works
partially, but I can live with what I have for the time being. The
amplifier works and is calibrated fairly well.

I remove the 7A24 (right hand vertical) plug-in and use that slot for
the 7A13. I leave the 7A26 (left hand vertical) and the two time
bases in place. I turn off the mainframe before removing or replacing
plug-ins.

Here's the issue: Assuming a stable display like above (except now
there are three traces), when I turn off the mainframe, I get a huge
round spot (about an inch across) for a second or so, and then the
machine goes dark.

Is this normal? (I wouldn't think so)
Has anyone seen this? And if so, what is it?
Is it harmful?
Or, horrors, does it indicate a significant problem with the plug-in
that is some how overloading the CRT circuits?

Any thoughts would be appreciated.

(*) This plug-in is sure different. The inputs are tied to relatively
large capacitors (voltage protection?); it has a *lot* of relays
(about 6 or 8 of them); the voltage divider switch is an old style
rotary switch (not a cam switch); there are three circuit board
stacked on top of each other; there a funny heat sinks mounted to
some transistors; the nice plug and ribbon cable hookups in newer
plug-ins are just not there; and the indicator for the comparator
voltage is an ancient, gear-driven odometer mechanism. The plastic
gear fastened to the metal driver for the Vc coarse switch is broken
in two. I see no way to get it off (some of the internal gear seem to
be pinned in place with no way to remove them). I put the two pieces
in place and fastened a wire around it all, and bound the wire
tightly. That lets me get 0-.999, 1-1.9999 and 2-2.999 volts on Vc
but not beyond. If I really need this feature, I'll find a newer
unit, and keep this one as an antique.

... John Hurst


P7001 with 7704A

kngtron
 

Hi group !! I have a 7704A with a P7001 digitizer mid-frame. Does
anybody have a manual for service / operators / or programming for
it ?


Tek Inline Resistor Networks-DYI Replacements

Jim Reese
 

I found an interesting item in our engineering lab here at work.
They are small blank inline (SIP) prototyping PCB's with edge solder
pins included. These should work for building your own inline
resistor networks to replace burnt or broken ones in scopes. Digikey
sells them (www.digikey.com). Made by Capital Advanced Technologies,
Uni-Sip brand. A typical Digikey P/N is 1010CA-ND, a 10 pin length
version. They are on page 820 and 821 of the current Digikey catalog
T022. Many different versions are available.

Jim Reese


New Photos

stack_overflow_ffff <distant_thunder_2000@...>
 

Hi folks,

Added a few photos for your viewing pleasure. My Tek album


2 575 Curve Tracers

Max Vaughan
 

I have just acquired two 575 transistor curve tracers..
These don't appear to be the plug in module type
that I am used to. (Own a 7458 and a 475)

I plan on cleaning them up, checking the tubes, etc.
They were originally bought from the local community collage as surplus.
My understanding was that they were working when pulled.
The gentleman I got them from was going to sell them on EBAY but
never got around to it. He ran a second hand store. He sold the
store to new owners. I went in there today and saw them, thought
I should grab them, the guy wanted $80 for them, but I got them
both for $30 apiece.

1st unit
missing the power cord
the switches have had there little plastic covers unscrewed and are missing.
switch seems to be broken inside.

2nd unit
looks to be in very good shape overall
camera bracket installed.

Both units:
screens don't have any burn marks. One looks white the other is different.
both are missing the fuse holder caps. Looks like a standard unit. Need to
know what size fuse, has a label but is a bit worn, wanted to be sure.
I haven't had the time to remove the covers yet, but it appears that the
insides are pretty clean looking from what I can see.

I would like some suggestions from the group on making sure that
I follow proper procedures to insure their working status. I don't have a
variac to hook them up to, so I thought a light bulb in series would
be ideal to check that there are no internal shorts when I flip the
power switch. Any other ideas would be appreciated.

I am not really interested in keeping them, and just want to clean them
up a bit and want to learn as much as I can so that I can accurately
describe their condition, I had originally planned to sell them both on
EBAY, but think that the
lesser of the two might go to one of you guys if there is any interest. Not
even sure of
there value but think that someone out there would be better suited to
restoring these
units or even making a good working unit from the both of them.

Would appreciate any and all thoughts, comments etc. Also would be nice to
grab some manuals, service and operating. prior to selling them. Any one
have a manual or a source where I can get a copy.

You guys are a pretty interesting group. Have learned a lot over the past
year.


7L13

crippo2uk <chj@...>
 

recently acquired late model 7L13 now works reasonably Ok - physical
damage to the leftmost rear connector and associated board now
repaired. BUT altho' the LED input strength indicator works ok (as
does the on-screen readout) on lin & 2DB inputs, it blanks completely
on 10DB input range, although the on-screen readout continues to work
perfectly to show the correct amplification/attenuation factor
depending on front panel settings.

Have looked at the manual, but before I delve too deeply (or decide
to leave well alone) I wonder if the gurus' out there have any
advice/help to give. Are there any likely quick fixes?

How someone could damage/drop one of these beauties I cannot
understand, but the philistines rule I suppose!

thanks in advance

Christopher


464 Intensity

benclarke_uk
 

I have recently acquired a Tek 464 storage scope, which works very
nicely, but I've noticed that the display intensity is not as bright
as most Tek scopes I have seen. In particular it is noticeably dimmer
than my 7603.

Looking at the specs of the two scopes I've noticed that the
acceleration potential is only 8.5Kv for the 464, whilst it is 15Kv
for the 7603.

Is this large difference in operating conditions something to do with
the requirements of a storage tube and is this why the display is
dimmer? Or is the tube on the way out?

Any enlightenment (!) would be appreciated,

Thanks...Ben


Tek camera

Craig Sawyers <c.sawyers@...>
 

Hi folks

Anyone know what a C-28 camera is? It must post-date my 1988 catalogue, so
any help with specifications and 'scope compatibility would be greatly
appreciated.

Cheers

Craig


Re: AD524

Don Black <jeans@...>
 

I guess this is the 524AD TV scope that Stan dismisses as of specialized and
limited use in his book. I have a sift spot for these as they were the first
Tektronix scopes I worked with in TV stations in the sixties / seventies. We
primarily used them for TV work and wave form analysis but also general work. I
always loved them and while the later machines would run rings around them,
they have a sweep delay and timing marker. Full of tubes that may be doubtful
too. But if I didn't live on the other side of the World I'd love to own it,
even just to take the covers off and gaze at all the beautiful circuitry.
In other words, I hope it finds a good home.
Don Black.

"Phil T." wrote:

Gents,

Please read below and reply directly to Steve if you are interested.

Thanks

Phil

From: "SMA.1" <SMA.1@ic24.net>
To: <phil@vaxxine.com>
Subject: AD524
Date: Thu, 8 Aug 2002 22:34:05 +0100
X-Mailer: Microsoft Outlook Express 6.00.2600.0000
X-Spam-Status: No, hits=3.3 required=7.0
tests=FROM_NAME_NO_SPACES,DEAR_SOMEBODY,DOUBLE_CAPSWORD,
HTML_WITH_BGCOLOR,MAILTO_LINK,DATE_IN_PAST_96_XX
version=2.31
X-Spam-Level: ***

Dear Sir,

I have an old Tektronix AD524 oscilloscope that someone gave me a few
years ago,
but I have no use for it. I wondered if you know anyone who would like to
have it, either
to restore or for spare parts. As far as I know it has one faulty valve
that needs replacing,
and I think it was calibrated before it became faulty. Whoever wants it
must be willing to
collect it.

Steve Andrews.
Bristol.
<mailto:SMA.1@ic24.net>SMA.1@ic24.net





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AD524

Phil T. <phil@...>
 

Gents,

Please read below and reply directly to Steve if you are interested.

Thanks

Phil

From: "SMA.1" <SMA.1@ic24.net>
To: <phil@vaxxine.com>
Subject: AD524
Date: Thu, 8 Aug 2002 22:34:05 +0100
X-Mailer: Microsoft Outlook Express 6.00.2600.0000
X-Spam-Status: No, hits=3.3 required=7.0
tests=FROM_NAME_NO_SPACES,DEAR_SOMEBODY,DOUBLE_CAPSWORD,
HTML_WITH_BGCOLOR,MAILTO_LINK,DATE_IN_PAST_96_XX
version=2.31
X-Spam-Level: ***

Dear Sir,

I have an old Tektronix AD524 oscilloscope that someone gave me a few
years ago,
but I have no use for it. I wondered if you know anyone who would like to
have it, either
to restore or for spare parts. As far as I know it has one faulty valve
that needs replacing,
and I think it was calibrated before it became faulty. Whoever wants it
must be willing to
collect it.

Steve Andrews.
Bristol.
<mailto:SMA.1@ic24.net>SMA.1@ic24.net


Re: WTB: working cheap 7L12?

Craig Sawyers <c.sawyers@...>
 

Anyone have a working 7L12 with warranty for a price
between the min ($214) and average ($377) as shown on

http://www.vaxxine.com/phil/scopes/plugin$.htm

Beware the statistics of small sample numbers! The price range is over only
three sales; assuming that the prices are randomly distributed, the error
goes as the square root of the samples. So to get a standard deviation
error of 10%, you need 100 samples. With three samples you have a 170%
error margin.

Typical prices that I've been able to find (apart from the dealer prices of
$1200!) are all around the $600 - $800 range. I found one (already sold)
for $199, but with no response to input signal. With an rf spectrum
analyser, this can really be a pig to fix, particularly if the mixer diodes
are zapped, and to realign afterwards.

I've just done a 1L5 (dc - 1MHz) that I bought from eBay (after fixing a
fault), and realigning that took a day following the Tek routine.

The only thing to do is to be patient. Occasionally a 7L12 will sneak
through at a really good price - then you pounce! I'm trying to do that
with a 7L5, but they all seem to go at around $400 a pop.

Craig


WTB: working cheap 7L12?

paul mcd. <paul46692@...>
 

Hi,

I was pointed to ebay to a 7L12 for $500 starting
bid, with no warranty, as is.

Anyone have a working 7L12 with warranty for a price
between the min ($214) and average ($377) as shown on

http://www.vaxxine.com/phil/scopes/plugin$.htm

Thanks,
Paul
Medford, MA

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Re: WTB 7L12 plug-in?

Doug Hale <doughale@...>
 


WTB 7L12 plug-in?

paul mcd. <paul46692@...>
 

Hi,

Anyone have a working 7L12 spectrum analyzer plug-in
for a 7603 o-scope for cheap?

Thanks
Paul
paul46692@yahoo.com

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HotJobs - Search Thousands of New Jobs
http://www.hotjobs.com


475 -15vdc power supply????

Steve <stever1k@...>
 

All

I have some problems with my -15 volt supply in a Tek 475 scope. Does any
one know what else the -15 vdc line supplies power to besides the probe
power connector on the back of the scope??? I can not find another thing
that it supplies power to. The voltage at the -15 TP reads about 23.4 volts,
my resistance checks per the manual are way out 67K vs 480 and 10K with
probes reversed. My -8 supply is down abit also -5.1 volts but the
resistance checks are good.

I am trying to get the -15v supply in line first per the directions in the
manual on repairing this supply before the -8.

Does anyone know anything else the -15vdc supplies power to besides the
Probe?? I am looking for an open someplace to account for the high
resistance checks.

steve


465 channel 1 dead

funkman010 <funkman010@...>
 

Does anyone know of a common problem with this? I have a service
manual but I have not started any trouble shooting yet.
Rudy


2236 oscilloscope

bbhoser <bbhoser@...>
 

I have several model 2236's and similar model oscilloscopes that need
repair. I understand that these units had a common power supply
problem. So common that at one time there was a kit assembled that
was supposed to cure the bulk of the failing power supplies.
Is there anyone who can either provide me with a list of the
components that need replacing or maybe direct me to a source that
can help me?
I am guessing that at one time there would have been a flyer or
publication that detailed what needed to be done.
Any help would be greatly appreciated.
Thank You, Ken Beamish


Re: Hard to get fuses

Frank R Borger <fborger@...>
 

In my previous job, I was often faced with the reverse of the "cross-the-pond"
part finding problem. I found that the Newark Electronics, now a subsidiary of
Premier Electronics, could often deliver items out of the English Premier
Electronics catalog. Only problem was occasionally a minimum order level and
the longer delivery times.

Those fuses are available from bussman (newark part no 28F051) and littlefuse,
(newark part no 27F650.) I'd call my local farnell office and see what they
could do.

With the global economy, I once discovered that I was sitting in Wisconsin USA,
ordering lcd counters from the Farnell England catalog that were designed in
Switzerland, manufactured in the Phillipines, but "made" by a company in
Indiana, about a half day drive away. Go figure.

Cheers

Frank Borger

Matthias Urban wrote:

Dear Group

can somebody give advice where to get the ACG 1/16 A fast blow fuses so
often found in older Tektronix equipment? Normal retail starts with 100 or
even 200 mA for this type of glass fuses.

I am in Europe and to get them somewhere on this side of the Atlantic would
be handy but I am grateful for any hint.

Thanks in advance for your help.

Matthias




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