Date   

Re: Need Transistor for 465M

Craig Sawyers <c.sawyers@...>
 

The generic name for a 151-0426-02 is D44H11
Current part from ONSemi (56c each) (Motorola as was, before confusing name
change. Don't start me on that beef!)

Craig


Re: Tek 465 repair hints, svc manual? (fix story)

Craig Sawyers <c.sawyers@...>
 

Never
anything really exciting from a capacitor, however, most of the
unfortunate electrolytic experiences were much more sedate than
usually described.
Well, I had an electrolytic blow up in my face once. The pressure relief
was facing me, and POW! Fortunately I wear spectacles, and that stopped the
goo going in my eyes. I can't quite remember exactly what abuse that
capacitor had had - I suspect that I was expecting more of it than it was
prepared to give (probably exceeding ripple current rating by an order of
magnitude or some such in a quick-and-dirty lash up).

Craig


subminiture light bulbs

arthurok_2000 <arthurok_2000@yahoo.com> <arthurok_2000@...>
 

radio shack might still sell some wire lead bulbs that
might work.
Using a 12vlt bulb running at 5 vlts should last a long time
"most consumer electronics bulbs arent rated for 50000 hours
life running a 12 vlt radioshack special at 5 vlts will
probably increase its life 10 fold


Re: Tek 465 repair hints, svc manual? (fix story)

E K
 

50 volt disc. Where did my signal go? Took the cap out and measures 4
ohms. No stress there but the cap failed. So it dont suprise me
The interesting thing is that this cap wasn't really "shorted". Part of what threw me off for a while during this whole process is that the 110V supply is really low-current compared to what I'm used to, so a tens of milliamps count.

As for ceramics, a physical crack opens all sorts of ways to build up a
short, primarily through whisker growth (metal used for plates is the
culprit). And again, if there is not enough energy in circuit to clear
Fascinating, the bit about whisker-growth.

Personally, I have never had a good visual show. Had some stinkers
The 465's cap didn't have enough to be noticeable. However, I have seen some really exciting things -- like balls of white fire from exploding IGBT's powered by a few amps at 300 VDC. Never anything really exciting from a capacitor, however, most of the unfortunate electrolytic experiences were much more sedate than usually described.









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Re: Inendiary discs, was Tek 465 repair hints, svc manual? (fix story)

Miroslav Pokorni
 

I am curious how much of real visual effects (smoke and flames) did you get
out of that cap. I do not doubt that there was enough energy in the circuit
but a ceramic disc does not provide much of combustible material.

Personally, I have never had a good visual show. Had some stinkers (magnet
wire seems to produce long lasting stink), had power transistors (TO-220)
that exploded, but not much smoke and never any flames.

The first place where I worked when I got out of school was a former
government lab. People had lot of time at hand and a favorite stunt played
on rookies was to take a housing of an electrolytic and put in a piece of
resistive wire and a small spool of photographic film (in those days film
was still celluloid, a euphemism for nitrocellulose, an explosive actually),
put that contraption over a voltage in a Tektronix scope and have rookie do
something that required scope. Few minutes after power on, there would be a
burst of flame and smoke. Poor guy would quickly snap power switch off and
start warring how to fix damage. And that is when fun started: some guys
would offer to arrange for an installment payment for scope (what would take
10 years with price of scope in early 60s and low salaries in Yugoslavia),
some others would offer to find a guy who can fix the scope (at an
exorbitant price) and game was played until end of day.

Fortunately for me, by time I was hired, the enterprise became commercial
and people had to do some work rather than play pranks, but I heard stories
and 'victims' were pointed, some of them were in management by that time.

Regards

Miroslav Pokorni

----- Original Message -----
From: "Craig Sawyers" <c.sawyers@tech-enterprise.com>
To: <TekScopes@yahoogroups.com>
Sent: Tuesday, February 18, 2003 1:58 AM
Subject: [TekScopes] Inendiary discs, was Tek 465 repair hints, svc manual?
(fix story)


Like a 3 volt p-p signal riding on 6 volts of DC
with a .01
50 volt disc. Where did my signal go? Took the cap out and measures 4
ohms. No stress there but the cap failed. So it dont suprise me
either,
but its not the first thing I go looking for either.
One evening, listening to the Television sound through a stereo amp (50W)
and speakers the amp died - smoke and flames. Took the lid off, and all
that had happened was a 0.1uF disc ceramic decoupler had gone short and
crowbarred the power supply. There was enough energy in the smoothing
caps
to incinerate it after the fuse had blown (around 20J).

Craig


Re: More digitizing stuff

Miroslav Pokorni
 

You are talking about 50 Msps? That puts your memory cycle to 20 ns, a
pretty tough requirement. Try Cray's gig with memory: butterfly it. Use
registers to store odd samples and on even samples write new sample and odd
one from register into double wide memory; you can extend this scheme to a
four wide memory, if your A/D can hack it. You can also use two A/D with
appropriate sample/holds to butterfly conversion.

Regards

Miroslav Pokorni

----- Original Message -----
From: <eric39392000@yahoo.com>
To: <TekScopes@yahoogroups.com>
Sent: Tuesday, February 18, 2003 4:39 PM
Subject: [TekScopes] More digitizing stuff


Well; I bought a HP 5180A on ebay, and I await it's arrival. It will
(I hope) acomplish what I had wanted: digitize an analog scope so
that I will have digital one-shot capabilty. On the down-side, the
HP5180A is the size of a small compact car, so I'm not sure where
I'm going to put it on my bench if it turns out to actually work.
I'm still working on MY version of a digitizer. I was trying to be
much too complicated with it, after discovering an obvious flaw in
my orginal design. I had first invisioned an A/D D/A , with a latch
in between until I realized that this layout would aquire only ONE
point on my signal display! DUH! No WONDER those DSO's require
memory! Then I went into microcontrollers to read and write the data
which would be my 250 or so samples but came to discover that my
thru-put would be much too slow for any decent signal frequency.
Then I went to a quickly-abandoned idea of using the output of my
THS720 (which goes to a printer to print a stored waveform) into my
analog scope, until Tektronix informed me that the ouput was in the
wrong form for putting into a D/A. Now I'm to a design that I should
have seen sooner: Just use RAM instead of getting overly complicated
with microcontrollers. I have an up-counter (good for 100Mhz)
counting addresses to my RAM, with the same clk used for my A/D. My
counter goes into some NAND gates which, after my count gets high
enough (500 samples), it turns off my read line, resets my counter
and starts writing to my D/A. This is a simple explaination; I have
some latches and buffers in there too. I hope to get 50MPS out of
this contraption if it works! :) The only problem is getting the
spare time at work to work on it! :)


Re: 7904 Switch Lamps

Miroslav Pokorni
 

From what I remember reading about those 'aged and selected' bulbs that
Tektronix used, they were selected for light output. I do not think that
those long life (50 000 hours) light bulbs are risk, even used, as far as
their life is concerned, because they are grossly underrated. There is
probably a risk of damaging a bulb in the process of removal, since lot of
them are with wire leads, instead of sockets.

Regards

Miroslav Pokorni

----- Original Message -----
From: "Stan & Patricia Griffiths" <w7ni@easystreet.com>
To: "Jay Mandel" <jmandel@nyc.rr.com>
Cc: "TekScopes" <TekScopes@yahoogroups.com>
Sent: Tuesday, February 18, 2003 11:05 AM
Subject: [TekScopes] Re: 7904 Switch Lamps


Hi Jay,

I don't happen to have any bulbs for the "A" and "B" positions of the 7904
mainframe horizontal mode switch.

I did come up with the following info in my search, however:

Horizontal mode switch = 670-1639-00

A and B bulbs = 150-0057-01
These are 7153AS15 "selected". The manual for 7904's above s/n B26 gives
a generic number of 17AS15 for these bulbs. Both numbers are rated at 5
Volts and 115 mA.

These bulbs are aged and "selected" but there was no explanation of what
they are selected for. My guess is that they are matched for light output.

The manufacturer is:

Oshino Electric Lamp Works, Ltd.
52 Minami Shinagawa 2 Chore
Shinagawa ku,
Tokyo, Japan

I would do a Google search on the manufacturer to see if there is a dealer
in the U.S. who will sell small quantities of these. They were used in a
LOT of Tek instruments and your best bet may be to pull some out of a
salvaged instrument. I know it is not the best idea to use used
incandescent bulbs, but these are specified to have a life of 50,000 hours
and I suspect the ones in the "A Dlyd" and "B Int" positions do not have
many hours on them . . .

If you find a good source for these, let us all know . . .

Stan
w7ni@easystreet.com

----- Original Message -----
From: Jay Mandel
To: w7ni@easystreet.com
Sent: Monday, January 27, 2003 10:06 AM


Hi. Do you have "grain of wheat" bulbs for 7904 Mainframe "A" & "B"
indicators?

If so, what would shipping be to 10023?

If not, any idea of a source?



Thanks





Jay Mandel





Re: CRT question

Miroslav Pokorni
 

So I suspect that in the 50's, there was a problem is getting high
deflection and bandwidth. It was also probably limited by the available
drive from wide band deflection amps at the time (the famous Tek
distributed
amp).
As I read it in 'trivia ad nauseam', 'The famous distributed amp' was ironed
out over a dinner in Portland, Oregon, between visiting guest, Bill Hewlett
and his host Howard Vollum. It appears that both of them were considering
idea of such an amp and the occasion of a visit, which apparently were
frequent, brought about crystallization of design.

Regards

Miroslav Pokorni


l20 manual

arthurok_2000 <arthurok_2000@yahoo.com> <arthurok_2000@...>
 

i have 2 l20s and a xerox of a l20/l30 manual
the 1l20 is a bit better then the l20 becaquse it has
calibrated dispersion and the person i bought my l20 from
about 20 yrs ago replaced it with a 1l20
if "jerky jerk" really cant find a manual maybe i can help
him " its becoming that old service manuals and certain hard
to come by parts cost more then the equipment is worth"
"alot of older service manuals have been thrown away over
the years by the companies that originally owned the
equipment and the surplus dealers never got them"


l20 manual

arthurok_2000 <arthurok_2000@yahoo.com> <arthurok_2000@...>
 

i have 2 l20s and a xerox of a l20/l30 manual
the 1l20 is a bit better then the l20 becaquse it has
calibrated dispersion and the person i bought my l20 from
about 20 yrs ago replaced it with a 1l20
if "jerky jerk" really cant find a manual maybe i can help
him " its becoming that old service manuals and certain hard
to come by parts cost more then the equipment is worth"
"alot of older service manuals have been thrown away over
the years by the companies that originally owned the
equipment and the surplus dealers never got them"


475 Vertical AC/DC Coupling switch

montanaaardvark <blombardi@cfl.rr.com> <blombardi@...>
 

Hi,


I just joined this group and did a search of the archives for some
info. Couldn't find anything on my problem.

A couple of months ago, I bought a 475 from someone on eBay. The
scope basically works fine. I haven't done a full calibration, but I
can check horizontal accuracy with a signal generator and that looks
good, check voltages with a few sources I trust and they look good,
and other overall checks.

It has one problem - both vertical channel coupling switches, the
slide switches that choose AC or DC coupling, or ground - are barely
working. While the switches on all the 475s I've used over the years
at various jobs "snapped" into place, these kind of "mush" into place.
Basically, I could get one channel into DC mode while the other is in
AC mode. The scope is usable, but I sure would like it better if I
could get some better switches in there.

I've gotten a reprint of the manual from W7FG, but don't really see
how accessible these switches are, or how rebuildable they are. Can
anyone advise me on this? Is the only source of parts another old 4X5
series scope? Is this something it's best to send out to get fixed?


Thanks,
Bob
W4ATM


More digitizing stuff

eric39392000 <eric39392000@yahoo.com> <eric39392000@...>
 

Well; I bought a HP 5180A on ebay, and I await it's arrival. It will
(I hope) acomplish what I had wanted: digitize an analog scope so
that I will have digital one-shot capabilty. On the down-side, the
HP5180A is the size of a small compact car, so I'm not sure where
I'm going to put it on my bench if it turns out to actually work.
I'm still working on MY version of a digitizer. I was trying to be
much too complicated with it, after discovering an obvious flaw in
my orginal design. I had first invisioned an A/D D/A , with a latch
in between until I realized that this layout would aquire only ONE
point on my signal display! DUH! No WONDER those DSO's require
memory! Then I went into microcontrollers to read and write the data
which would be my 250 or so samples but came to discover that my
thru-put would be much too slow for any decent signal frequency.
Then I went to a quickly-abandoned idea of using the output of my
THS720 (which goes to a printer to print a stored waveform) into my
analog scope, until Tektronix informed me that the ouput was in the
wrong form for putting into a D/A. Now I'm to a design that I should
have seen sooner: Just use RAM instead of getting overly complicated
with microcontrollers. I have an up-counter (good for 100Mhz)
counting addresses to my RAM, with the same clk used for my A/D. My
counter goes into some NAND gates which, after my count gets high
enough (500 samples), it turns off my read line, resets my counter
and starts writing to my D/A. This is a simple explaination; I have
some latches and buffers in there too. I hope to get 50MPS out of
this contraption if it works! :) The only problem is getting the
spare time at work to work on it! :)


Re: 7904 Switch Lamps

Craig Sawyers <c.sawyers@...>
 

Horizontal mode switch = 670-1639-00

A and B bulbs = 150-0057-01
These are 7153AS15 "selected". The manual for 7904's above s/n
B26 gives a generic number of 17AS15 for these bulbs. Both
numbers are rated at 5 Volts and 115 mA.
Armed with that crucial information, I found that Farnell part number
315-9334 is a 3mm diameter 6.35mm long bulb, with a rating of 5V 120mA and a
20,000 hour lifetime. Price is 30p(UK) - so say 50c. And you have to order
10 off.

Or, here is an identical rating one. 5V at 115mA, same size as above,
Farnell part number 328-868. 37p each and minimum quantity of 5 off.

Alternatively try using a white LED. These drop 3.6V at a maximum of 30mA,
so a series resistor is necessary. Part 941-852, 3mm diameter 5.4mm long
and cost ?2.75. Probably only need 5-10mA for the same brightness as the
incandescent bulbs, so a tiny 150 ohm 1/8Watt resistor should do the trick.

Incidentally, Stan's figure for 50,000 hour ifetime works out at 8 hours a
day, 200 days a year for 30 years. Or if left on 24/7 they would burn for
nearly 6 years. Bet not many have blown, and used ones probably have many
good years left.

Craig


Re: 7904 Switch Lamps

Stan & Patricia Griffiths <w7ni@...>
 

Hi Jay,

I don't happen to have any bulbs for the "A" and "B" positions of the 7904 mainframe horizontal mode switch.

I did come up with the following info in my search, however:

Horizontal mode switch = 670-1639-00

A and B bulbs = 150-0057-01
These are 7153AS15 "selected". The manual for 7904's above s/n B26 gives a generic number of 17AS15 for these bulbs. Both numbers are rated at 5 Volts and 115 mA.

These bulbs are aged and "selected" but there was no explanation of what they are selected for. My guess is that they are matched for light output.

The manufacturer is:

Oshino Electric Lamp Works, Ltd.
52 Minami Shinagawa 2 Chore
Shinagawa ku,
Tokyo, Japan

I would do a Google search on the manufacturer to see if there is a dealer in the U.S. who will sell small quantities of these. They were used in a LOT of Tek instruments and your best bet may be to pull some out of a salvaged instrument. I know it is not the best idea to use used incandescent bulbs, but these are specified to have a life of 50,000 hours and I suspect the ones in the "A Dlyd" and "B Int" positions do not have many hours on them . . .

If you find a good source for these, let us all know . . .

Stan
w7ni@easystreet.com

----- Original Message -----
From: Jay Mandel
To: w7ni@easystreet.com
Sent: Monday, January 27, 2003 10:06 AM


Hi. Do you have "grain of wheat" bulbs for 7904 Mainframe "A" & "B" indicators?

If so, what would shipping be to 10023?

If not, any idea of a source?



Thanks





Jay Mandel


Re: Need Transistor for 465M

Stan & Patricia Griffiths <w7ni@...>
 

Hi OM,

I found a little info for you regarding the transistor you need for your
465M:

The generic name for a 151-0426-02 is D44H11 but I could find no data on
what it is selected or matched for.

Stan
w7ni@easystreet.com

----- Original Message -----
From: <wa8mcd@yahoo.com>
To: <TekScopes@yahoogroups.com>
Sent: Monday, January 27, 2003 12:21 PM
Subject: [TekScopes] Need Transistor for 465M


Can anyone help with this, I have a bad q552 Tektronnix part #151-
0426-02 when I look up a generic part all I get is "NPN Selected"
Is there a spefic transistor number I should look for? Thanks for
the help




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Re: 545B diode

Stan & Patricia Griffiths <w7ni@...>
 

Hi Chuck,

The 152-008 (also known as 152-0008-00) is a T12G or a 1N270.

Stan
w7ni@easystreet.com

----- Original Message -----
From: "Chuck Miles" <cmm@epud.net>
To: "Stan Griffiths" <w7ni@easystreet.com>
Sent: Thursday, January 23, 2003 1:51 PM
Subject: 545B diode


Stan,

In my 545B (s/n 005573), there are 3 diodes with the p/n: 152-008, and
simply described as "Germanium" diodes, D122, D131 and D231. Do you know
of
a "1Nxxxx" replacement for them?

Thanks.

Chuck


7704A Bandwidth

Stan & Patricia Griffiths <w7ni@...>
 

About January 16, you send an email to TekScopes about measuring 7704A
bandwidth and you mentioned a cal fixture you had just bought. You said it
was a 067-0589-01 which I thought was just a plugin extender.

You mentioned it had a leveler circuit in it and this sounds more like an
067-0532-01 to me. Do I have these numbers correct? During a quick search,
I could not find reference to an "01" version of the 067-05898-00.

You were also surprised that the 7704A might make 350 MHz when the spec is
only 230 MHz. There are a couple of explanations for this: 1) At
bandwidths above 100 MHz, sometimes the transient response is not gaussian
and the formula "Bandwidth X Risetime = 0.35" does not hold. 2) Sometimes
the original spec will be somewhat conservative but the manufacturer of the
parts will improve them over time and the bandwidth will actually go up.
There are lots of reasons why Tek would not want to change the spec after it
is once published . . . even to improve it.

Stan
w7ni@easystreet.com


Re: Tektronix 465M Oscilloscope Knob

Stan & Patricia Griffiths <w7ni@...>
 

Hi dnboot,

I have not seen a response to your inquiry about a knob for your 465M. I
hope you have found one but just in case you haven't, here is some
information for you . . . not all good. That knob is unique to the 465M and
about the only place to get one if is from a scrapped instrument. You are
looking for Tek Part Number 366-1722-00. You might try Deane Kidd
dektyr@teleport.com and the following web site: http://www.sphere.bc.ca

By the way, I have repaired a similar knob from another instrument by gluing
it with modler's liquid plastic cement. Sorry this response is so late but
I am WAY behind in my email.

Stan
w7ni@easystreet.com

----- Original Message -----
From: <dnboot@msn.com>
To: <TekScopes@yahoogroups.com>
Sent: Tuesday, January 07, 2003 2:59 PM
Subject: [TekScopes] Tektronix 465M Oscilloscope Knob


I have a Tektronix 465M Oscilloscope and need the knob that sets the
voltage, this is one of two knobs on the left side of scope if
looking a display, it has a main dial with a red knob in the center.
the one I need is the upper, that I beleave is the same as the lower.
If anyone would have one I could buy, Please E-mail me price for knob
and shipping, My zip is 50302.

Thanks,

dnboot@msn.com




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Re: Differential probe

Marcello Pellerano
 

Miroslav, Craig, thanks for your advices.
Anyway I should like to build an "high-power" application probe, you may find one of these in the RS Components catalogue.
Here is the (veeery long...) link:

http://www1.rs-components.it/cgi-bin/bv/browse/Module.jsp?BV_SessionID=@@@@1861999798.1045580493@@@@&BV_EngineID=ccccadchiflldilcfngcfkmdgkldfhm.0&3223033382=3223033382&catoid=-164734051


Thanks again.
Marcello


Re: CRT question

Craig Sawyers <c.sawyers@...>
 

My guess is, just like analog meters, linearity between 1/3 and
2/3 is best.
The numbers are probably more generous for CRT, but there is something
there.
I think that there is a bandwidth issue too. The 545A is the same vintage
as the 575 curve tracer. The 545A has a 10ns rise time for the mainframe
(35MHz) and has 4cm deflection. The 575 has 8cm. Now the CRT for the 575
also went in the 525 TV waveform processing 'scope, with a maximum bandwidth
of 5MHz.

So I suspect that in the 50's, there was a problem is getting high
deflection and bandwidth. It was also probably limited by the available
drive from wide band deflection amps at the time (the famous Tek distributed
amp).

Craig

179101 - 179120 of 182356