开云体育

I'm very pleased to have found this group as I am a great lover and
collector of vacuum tube Tek scopes here in Melbourne Australia. My
collection includes examples of the 310A, 502, 524AD, 529, 533A, 535A,
547 (my workhorse bench scope), 549, the enormous 555 scoposaurus, 575
and many plugins including a homebrew spectrum analyzer built into an
old plugin caracass and a Japanese commercial transistor testing
plugin built into a Tek blank. I also have a number of other
manufacturers' scopes as well, and sundry other pieces of Tek
equipment and manuals.

My interests include restoration and using these wonderful machines. I
can remember the first time I saw an oscilloscope and being fascinated
by it at the age of about 10. A few years later I saw my first Tek - a
549 with a 1A4 plugin - and it was a really mind blowing experience
compared to the sorts of scopes experimenters had access to in the
1960s. Now I'm very happy to be able to own some of these
instruments and fully understand their workings.

I hope I will be able to contribute to the discussions here, both in
the way of helping others and learning along the way.

Cheers,

Morris Odell

At 5:07 PM +0000 2001/4/08, Doug wrote:

Hi,
my name is Doug and I am looking for a User Manual and Service manual
for a Tek 454 Scope. I had seen a source on the web but can't seem
to find it now. Does anyone know were I might find these manuals?
I understand tek is very expensive for printed versions of the manual

Don't forget to monitor eBay!


-----------------------------------------------------------------
Michael Dunn | Surround Sound Decoder & Stereo Enhancer
Cantares | Self-Amplified Speakers, Test Equipment
74 George St. | Ambisonic Surround Sound CDs and Recording
Waterloo, Ont. | (519) 744-9395 (fax: 744-7129)
N2J 1K7 | mdunn@...
Canada |
-----------------------------------------------------------------

You may also want to look at www.big-list.com under "manual
dealers". I have had good luck finding manuals from several entries
in this list.

Jim

Hi Doug,

I doubt you could get that manual from Tek at any price these days. Anyway,
if you go to the following URL, you can find a list of companies and people
who can supply you with copies of Tek manuals:

<> Click on the Tek reference section and keep looking
around. You will find the list you are looking for.

Stan
w7ni@...

Doug wrote:

Try this one. Bill



Doug wrote:

Hi,
my name is Doug and I am looking for a User Manual and Service manual
for a Tek 454 Scope. I had seen a source on the web but can't seem
to find it now. Does anyone know were I might find these manuals?
I understand tek is very expensive for printed versions of the manual

Thanks
DOug


Yahoo! Groups Sponsor

[E*TRADE. It's your money]

To unsubscribe from this group, send an email to:
TekScopes-unsubscribe@...



Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

Hi,
my name is Doug and I am looking for a User Manual and Service manual
for a Tek 454 Scope. I had seen a source on the web but can't seem
to find it now. Does anyone know were I might find these manuals?
I understand tek is very expensive for printed versions of the manual

Thanks
DOug

Hi All

My old faithful 7904 has started to have a little problem with the display.

It will run for hours or days with no problem. Then it will start to drift
the display up and down, this is the trace/s and readouts as well. Note this
is not on oscillation up and down. It will shift up for awhile, then drop
down lower then it should be for awhile. I am talking about a 1/2 CM or so.
Everything is always on screen, it just gets annoying after awhile.

I found I can turn off the readouts and it will stop. Turn the readouts back
on, and it will be fine again for a few hours or days.

Any ideas what might be going on and where to start looking before I tear
into it.



Thanks,
Don

BTW Hi Mark Gurries glad to see you on the list.

Eventually I have got it!
The entire story is reported at

I want to thank you once again the group for the support and in
particular Mr. Fred de Vries who helped significantly.
Until next time, ciao.

Hi Michael,

Thanks for the rundown on the 7S14/5S14. I knew the 5S has come before the 7S and
that they had similar specifications, but since I have never seen a 7S version, I
did not know they were THAT similar!

Stan
w7ni@...

Michael Dunn wrote:

Hi,

there is a 6CZ5 and a 2AS-15 in the regulation loop of the Tek 555
heater supply voltage. The 2AS-15 is probably the one you mean.
Quoting from the 555 manual:

I hope this helps.

Laurent Lamesch

Yep. That's just what I needed. Thanks much!

-- John Rehwinkel

I need someone to refresh my memory. The old Tek scopes with
the separate power supplies (555 and similar) had an unusual
filament voltage regulator that operated with a saturable core
reactor. Part of the feedback circuit involved a tube that (I
think) was very sensitive to its filament voltage. I have a
clear mental image of the tube, it was a glass octal type with
a horizontal filament and a cylindrical plate around it. I'm
looking for the type number of this tube. Anybody know offhand
or have a manual with this info? Otherwise, I'll probably have
to wait 'til the next hamfest and see if one of the Tek manual
vendors will let me have a peek.

-- Thanks,
John Rehwinkel KG4L
spam@...

Hi,

there is a 6CZ5 and a 2AS-15 in the regulation loop of the
Tek 555 heater supply voltage. The 2AS-15 is probably the one
you mean.
Quoting from the 555 manual:
'The circuit operates by regulating the voltage applied to
the primary winding of the [heater supply] transformer [T750].
Any variation in the amplitude of the ac output from T750
appears across the secondary winding between terminals 11
and 12 of the transformer and is applied to the heater of
the special diode tube, V799 [2AS-15]. The amplitude variation
causes the diode to conduct more or less current, depending on
the direction of the change, and produces a voltage change in
the plate circuit of V799.'

I hope this helps.

Laurent Lamesch

John Rehwinkel wrote:

At 6:52 PM -0800 2001/3/31, dd@... wrote:

> For example, my 7S14

has a sticker on it that says 5S14 too.

For that plugin the guts are the same (originally a 5000 series plugin).
Is there some kind of adapter board in the back that has the 7000 edge
connectors on it?

Sure enough, each edge connector is a small card with some components.


At 6:49 PM -0800 2001/3/31, Stan or Patricia Griffiths wrote:

and found that that very seller had just a few weeks before that purchased a
known dead HP-01 for about $200. I further found out that he had purchased a

What a story!

> has a sticker on it that says 5S14 too.

I wonder what that is all about . . . ?? Just a quick look will tell you
that a 5000 Series plugin will not fit a 7000 series mainframe and vice-versa
and they are not electrically compatible, either.

See above.

And, Michael H. sent me the following information:

The 7S14 was originally designed as 5S14 and because of the fact that the plugins for the 7k Series are longer,
TEK Integrated it in a 7k Scopes housing and added some adapter prints to make it 7k scope compatible.
This plgin was the "poor peoples" Sampler especially for the Lower Bandwith 100 and 200 MHz Mainframes.

Take care with this plugin: it contains little battery cells in the sampling stage that may be empty.

This is actually the only plugin that i know that contains 5k Series Technology (and i own quite a complete collection).

The 7k Scopes interface differs mechanically and electrically a lot from the 5k scopes. the 5k scopes actually use a mechanics that is mechanically identical to the TM 500 System.

Do you think maybe a bad output transistor? thanks for your help.
Mike

Maybe, Mike. Looking at my 454 manual, I see that the collector

voltage on

both Q394 and Q494 should be about 41-42 volts measured with a

voltmeter.

Also, I don't think the voltmeter should "load" the circuit such

that the

voltage changes very much because of attaching the voltmeter.

There are TWO

sets of vertical deflection plate pins. Are you sure all FOUR pins

are

connected?

A good troubleshooting method for balanced circuits like vertical

amplifiers

is to short together like points such as the upper and lower CRT

deflection

plates in order to force them to be at the same voltage. This

should force

the trace to be centered vertcially and should not damage the

circuitry. If

the trace is centered with the CRT vertical deflection plates

shorted

together (this is also the same as shorting the collectors of the

vertical

output stage transistors together), it is a very good indication

that the CRT

itself is good.

Next, you can remove the short and move it to the emitters of Q394

and Q494.

If the trace is once again centered vertically, most likely Q394

and Q494 are

good. Next, move the short to the base of Q374 and the base of

Q474. If the

trace is once again centered, most likely Q374 and Q474 are good.

You can

work your way a stage at a time through the vertical amplifier this

way until

you do not get a centered trace. Now you are very close to the

problem and

it is time to check for shorted or open transistors in this

immediate area.

Be careful not to brush ground with the loose end of the short wire

while the

instrument is powered up and the other end is connected because you

will have

a LOT of destroyed transistors if you do that . . . Also, be sure

BOTH ends

of the short wire are disconnected before connecting one end to

another part

of the circuit . . .

Let me know how this works for you.

Stan

w7ni@e................................................................
......................................................................
Stan,
I got no farther than Q374 and Q474,
I replaced both transistors and the output transistors collector
voltage dropped to 40.5 and 35.2 volts. The trace is now in the upper
half of screen and I have a small deflection of a square wave signal
so gain is poor. Should Q374and Q474 be a matched duo?
This thing about having to touch the collectors to start the
transistors to conduct is really odd, you don't have to leave the
probe on just make a momentary contact with deflection pin or
collector.
I don't have a manual for this thing so I'm working mostly in the
dark. I would like to thank you very much for all the help you have
given me. mike

Hi Mike,

You really need a 454 manual. The one I was using to remind me of the Q
numbers was the one I now have up for sale on eBay right now. You should
look at auction #1226363944 and think about bidding on it.

You probably have found at least one bad transistor, or maybe two. You can
test those for most defects with an ohmmeter right on the bench.

The next thing I would do is short the emitters of Q394 and Q494 and see if
this forces the trace to the center of the screen. If it does, then I would
say Q394 and Q494 are good and you need to progress with the shorting process
to the previous stage, etc.

You really need the manual . . .

Stan
w7ni@...

--- In TekScopes@y..., Stan or Patricia Griffiths <w7ni@e...> wrote:

mtmpsmp@y... wrote:

--- In TekScopes@y..., Stan or Patricia Griffiths <w7ni@e...>

wrote:

mtmpsmp@y... wrote:

I have a 454 that has no vertical deflection on ch1 or ch2,

using

another scope I am able to trace signal from the preamps to

the

deflection plates. The sweep appears to be in good shape and

the

trace is centered on crt. ( position controls have no effect

on

trace) What I don't understand is that I have a voltage

imbalance

on

vertical plates and the trace is still centered!

Boy! I don't understand that either. I have to wonder if the

voltage

unbalance is actually getting to the deflection plates inside

the

CRT.

Perhaps there is a broken connection INSIDE the CRT. If the

unbalance is

actually on the CRT plates, I don't see how the trace can be

centered

vertically . . .

Stan
w7ni@e...

.....................................................................

....................................................................

..

Stan,
Upon further investigation I have found that when the scope is
turned on the collector voltage is the same (74.6 volts) on each
output device. The voltage will stay in that condition ( flat
centered trace) until I start making voltage measurements with my
voltmeter ( high impedance digital) then the top connecter drops

to

56.8 -62.0 volts and the bottom to 32.5 -29.8 volts, the voltage

of

course being determined by position control. The trace is at this
point off screen in all modes ( chop, add ect) I can seem only to
bring this condition on by taking voltage measurement on either

vert

plate.
Do you think maybe a bad output transistor? thanks for your help.
Mike

Maybe, Mike. Looking at my 454 manual, I see that the collector

voltage on

both Q394 and Q494 should be about 41-42 volts measured with a

voltmeter.

Also, I don't think the voltmeter should "load" the circuit such

that the

voltage changes very much because of attaching the voltmeter.

There are TWO

sets of vertical deflection plate pins. Are you sure all FOUR pins

are

connected?

A good troubleshooting method for balanced circuits like vertical

amplifiers

is to short together like points such as the upper and lower CRT

deflection

plates in order to force them to be at the same voltage. This

should force

the trace to be centered vertcially and should not damage the

circuitry. If

the trace is centered with the CRT vertical deflection plates

shorted

together (this is also the same as shorting the collectors of the

vertical

output stage transistors together), it is a very good indication

that the CRT

itself is good.

Next, you can remove the short and move it to the emitters of Q394

and Q494.

If the trace is once again centered vertically, most likely Q394

and Q494 are

good. Next, move the short to the base of Q374 and the base of

Q474. If the

trace is once again centered, most likely Q374 and Q474 are good.

You can

work your way a stage at a time through the vertical amplifier this

way until

you do not get a centered trace. Now you are very close to the

problem and

it is time to check for shorted or open transistors in this

immediate area.

Be careful not to brush ground with the loose end of the short wire

while the

instrument is powered up and the other end is connected because you

will have

a LOT of destroyed transistors if you do that . . . Also, be sure

BOTH ends

of the short wire are disconnected before connecting one end to

another part

of the circuit . . .

Let me know how this works for you.

Stan

w7ni@e................................................................
......................................................................
Stan,
I got no farther than Q374 and Q474,
I replaced both transistors and the output transistors collector
voltage dropped to 40.5 and 35.2 volts. The trace is now in the upper
half of screen and I have a small deflection of a square wave signal
so gain is poor. Should Q374and Q474 be a matched duo?
This thing about having to touch the collectors to start the
transistors to conduct is really odd, you don't have to leave the
probe on just make a momentary contact with deflection pin or
collector.
I don't have a manual for this thing so I'm working mostly in the
dark. I would like to thank you very much for all the help you have
given me. mike

Is anyone else suspicious of some of the auctions on eBay.

Sure. On the other hand, there are dealers selling test equipment who are
completely legitimate, but have no idea how to use or test it. Example:
Outback Equipment

In one
auction, the seller says he doesn't know how to use it, so therefore
can't guarantee it (a 5L14 analyzer), yet has pictures of it in full
operation.

Maybe he lucked out and the switches were set properly to get a display.
You are right though, it sounds fishy.

Another of his auctions for a storage mainframe - he says
he doesn't know how to use the storage... Gimme a break.

I find this fairly believable... analog storage scopes are tricky even if
you know what you're doing... and the 7834 is pretty complicated.

p.s., Are 5000 and 7000 plug ins compatible?

No.

For example, my 7S14
has a sticker on it that says 5S14 too.

For that plugin the guts are the same (originally a 5000 series plugin).
Is there some kind of adapter board in the back that has the 7000 edge
connectors on it?

Hi Michael,

I'm afraid you are right. There are scammers everywhere. When I see words
like "I don't know how to use it", I assume its broken and bid accordingly.
I sell a LOT of stuff on eBay, some of it I can't test and sell as is.
Sometimes all I can do is plug it in and look for smoke and report that it
did not smoke, if that is all I know about it . . . In the case of a recent
CB radio I sold, I didn't even power it up . . . and said so. I did say that
I had no reason to believe it did not work and that it came from an estate
sale. I saw no obviously smoked or burned parts and described any physical
damage and took several pictures. After that, it is buyer beware . . . I
also priced it cheap . . . $4.

In another case, I was selling an HP-01 1975 vintage digital calculator
watch. This one worked great and had an extra watch band, the book, original
box, etc. It went for $2300 . . . ! ! Before I put it up for sale, I
looked at previous HP-01 auctions and noted one that eventually sold for
about $400. The seller claimed he did not know if it worked or not and said
the battery was dead so he could not test it . . . I investigated further
and found that that very seller had just a few weeks before that purchased a
known dead HP-01 for about $200. I further found out that he had purchased a
couple of known working HP-01's for about $1200-$1500. I can't believe he
could not install a battery and see if it worked or not . . . he had
batteries in the other two HP-01's and they are available where ever watch
batteries are sold . . . He certainly knew how much a "good" HP-01 was worth
. . . My opinion: he was fraudulant in his presentation and knew EXACTLY
what he was doing . . . The buyer was Japanese . . . with little or no
recourse . . . I notified eBay of my observations and never heard a word
about it from anyone . . . including eBay.

Buyer beware . . .

Stan
w7ni@...

More comments below . . .

Michael Dunn wrote:

Is anyone else suspicious of some of the auctions on eBay. In one
auction, the seller says he doesn't know how to use it, so therefore
can't guarantee it (a 5L14 analyzer), yet has pictures of it in full
operation. Another of his auctions for a storage mainframe - he says
he doesn't know how to use the storage... Gimme a break.

In the case of the 5L14N, it is one of the hardest instruments to use that I
have ever encountered . . . and I used to sell them as a Tektronix Sales
Engineer from 1979-1989, specializing in Tek Spectrum Analyzers . . .

I expect some people might do this to cover up a non-working
function, instead of just coming out and saying (e.g.) "Storage
doesn't work"!

Comments?

p.s., Are 5000 and 7000 plug ins compatible?

NO.

For example, my 7S14
has a sticker on it that says 5S14 too.

I wonder what that is all about . . . ?? Just a quick look will tell you
that a 5000 Series plugin will not fit a 7000 series mainframe and vice-versa
and they are not electrically compatible, either.

Stan
w7ni@...

mtmpsmp@... wrote:

--- In TekScopes@y..., Stan or Patricia Griffiths <w7ni@e...> wrote:

mtmpsmp@y... wrote:

I have a 454 that has no vertical deflection on ch1 or ch2, using
another scope I am able to trace signal from the preamps to the
deflection plates. The sweep appears to be in good shape and the
trace is centered on crt. ( position controls have no effect on
trace) What I don't understand is that I have a voltage imbalance

on

vertical plates and the trace is still centered!

Boy! I don't understand that either. I have to wonder if the

voltage

unbalance is actually getting to the deflection plates inside the

CRT.

Perhaps there is a broken connection INSIDE the CRT. If the

unbalance is

actually on the CRT plates, I don't see how the trace can be

centered

vertically . . .

Stan
w7ni@e...
.....................................................................

......................................................................
Stan,
Upon further investigation I have found that when the scope is
turned on the collector voltage is the same (74.6 volts) on each
output device. The voltage will stay in that condition ( flat
centered trace) until I start making voltage measurements with my
voltmeter ( high impedance digital) then the top connecter drops to
56.8 -62.0 volts and the bottom to 32.5 -29.8 volts, the voltage of
course being determined by position control. The trace is at this
point off screen in all modes ( chop, add ect) I can seem only to
bring this condition on by taking voltage measurement on either vert
plate.
Do you think maybe a bad output transistor? thanks for your help.
Mike

Maybe, Mike. Looking at my 454 manual, I see that the collector voltage on
both Q394 and Q494 should be about 41-42 volts measured with a voltmeter.
Also, I don't think the voltmeter should "load" the circuit such that the
voltage changes very much because of attaching the voltmeter. There are TWO
sets of vertical deflection plate pins. Are you sure all FOUR pins are
connected?

A good troubleshooting method for balanced circuits like vertical amplifiers
is to short together like points such as the upper and lower CRT deflection
plates in order to force them to be at the same voltage. This should force
the trace to be centered vertcially and should not damage the circuitry. If
the trace is centered with the CRT vertical deflection plates shorted
together (this is also the same as shorting the collectors of the vertical
output stage transistors together), it is a very good indication that the CRT
itself is good.

Next, you can remove the short and move it to the emitters of Q394 and Q494.
If the trace is once again centered vertically, most likely Q394 and Q494 are
good. Next, move the short to the base of Q374 and the base of Q474. If the
trace is once again centered, most likely Q374 and Q474 are good. You can
work your way a stage at a time through the vertical amplifier this way until
you do not get a centered trace. Now you are very close to the problem and
it is time to check for shorted or open transistors in this immediate area.
Be careful not to brush ground with the loose end of the short wire while the
instrument is powered up and the other end is connected because you will have
a LOT of destroyed transistors if you do that . . . Also, be sure BOTH ends
of the short wire are disconnected before connecting one end to another part
of the circuit . . .

Let me know how this works for you.

Stan
w7ni@...

Is anyone else suspicious of some of the auctions on eBay. In one auction, the seller says he doesn't know how to use it, so therefore can't guarantee it (a 5L14 analyzer), yet has pictures of it in full operation. Another of his auctions for a storage mainframe - he says he doesn't know how to use the storage... Gimme a break.

I expect some people might do this to cover up a non-working function, instead of just coming out and saying (e.g.) "Storage doesn't work"!

Comments?

p.s., Are 5000 and 7000 plug ins compatible? For example, my 7S14 has a sticker on it that says 5S14 too.

-----------------------------------------------------------------
Michael Dunn | Surround Sound Decoder & Stereo Enhancer
Cantares | Self-Amplified Speakers, Test Equipment
74 George St. | Ambisonic Surround Sound CDs and Recording
Waterloo, Ont. | (519) 744-9395 (fax: 744-7129)
N2J 1K7 | mdunn@...
Canada |
-----------------------------------------------------------------

Hi all, :)

Not exactly a TekSCOPE, and not catastrophic, but I have a DM501A with a
VERY bright LED display. A glance at the cct diagram does not suggest (to
me) the possibility of adding a simple series resistor for the common side
of the LED display. Anyone know enough about the unit to suggest a fix?

Thanks and regards,
:)
Michael Dunn
(the other one)
<g>