Topics

Tektronix 7S14 - URGENT!


JOSE V. GAVILA (EB5AGV/EC5AAU) <eb5agv@...>
 

Hello!

I am in need of some info about the 7S14 plug-in... is it worth $150 in
operating condition?. How does it performs?

Please, any information will be welcomed.

Thanks!

JOSE
----------------------------------------------------------------------
73 EB5AGV / EC5AAU - JOSE V. GAVILA
La Canyada - Valencia (SPAIN)

EB5AGV Vintage Radio Site: http://www.geocities.com/eb5agv

European Boatanchors List: http://groups.yahoo.com/group/euro_ba_swap


John Rehwinkel <spam@...>
 

I am in need of some info about the 7S14 plug-in... is it worth $150
in operating condition?. How does it performs?
I used one of these plugins for a couple of years back in the 1980's.
It worked just dandy for me (measuring risetimes of pulsed electron
guns), under some fairly demanding conditions.

I'd happily pay $150 for one in operating condition.

-- John Rehwinkel
spam@fgm.com


Michael Dunn <mdunn@...>
 

> I am in need of some info about the 7S14 plug-in... is it worth $150
> in operating condition?. How does it performs?
I have one, though I haven't really used it. It seems to work ok, except for a slight "ghost" signal on one trace. Think mine was closer to U$100! If you get a manual too, I will gladly pay a bit for some photocopies.

Keep in mind that these samplers typically have more finicky triggering circuits than a normal module. Also, all the buttons on mine are quite sluggish -- almost binding. I'm sure that'll improve with a bit of maintenance...

Michael


Stan or Patricia Griffiths <w7ni@...>
 

My opinion is that a working and calibrated 7S14 that meets all of its
original specifications should be worth $150. The problem is that almost
nobody has the ability to determine if one is really working properly or
not. You have to have a very fast rise and clean pulse generator, an
amplitude calibrated 50 ohm voltage source, and a fast time mark generator at
a very minimum in order to get any idea if it really works correctly.

If it does not work correctly, it may be impossible to find the parts you
need to fix it. The most vulnerable parts are the sampling diodes and I
suspect they are impossible to find, but I have to admit I have not searched
for any. I am sure there are other critical, hard to find parts in the 7S14.

Does this unit come with a "money-back guarantee" . . . ?

Stan
w7ni@easystreet.com

JOSE V. GAVILA (EB5AGV/EC5AAU) wrote:

Hello!

I am in need of some info about the 7S14 plug-in... is it worth $150 in
operating condition?. How does it performs?

Please, any information will be welcomed.

Thanks!

JOSE
----------------------------------------------------------------------
73 EB5AGV / EC5AAU - JOSE V. GAVILA
La Canyada - Valencia (SPAIN)

EB5AGV Vintage Radio Site: http://www.geocities.com/eb5agv

European Boatanchors List: http://groups.yahoo.com/group/euro_ba_swap

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



Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/


Mark Kahrs <kahrs@...>
 

And don't forget those batteries in the sampling diode bias.
I personally think that the S14 is a washout. You can only go to
1 GHz with it and with a 79xx you can already get to 500 MHz.
So, why go to sampling for the extra 500 Meg? Why not just go
for the gusto and get a 7S11/7T11 pair?

As I remind everyone, you get what you pay for (and that includes advice)

(Most of the time)

Mark.


Don Black <jeans@...>
 

Hi,
I haven't had any experience with sampling CROs but believe the plugins can
be damaged with input signals greater than 5 to 10 volts (depending on model). Be
careful to limit input signals as they're very difficult to obtain parts or
service.
Perhaps others have some comments on this.
Good Luck, Don Black.

Stan or Patricia Griffiths wrote:

My opinion is that a working and calibrated 7S14 that meets all of its
original specifications should be worth $150. The problem is that almost
nobody has the ability to determine if one is really working properly or
not. You have to have a very fast rise and clean pulse generator, an
amplitude calibrated 50 ohm voltage source, and a fast time mark generator at
a very minimum in order to get any idea if it really works correctly.

If it does not work correctly, it may be impossible to find the parts you
need to fix it. The most vulnerable parts are the sampling diodes and I
suspect they are impossible to find, but I have to admit I have not searched
for any. I am sure there are other critical, hard to find parts in the 7S14.

Does this unit come with a "money-back guarantee" . . . ?

Stan
w7ni@easystreet.com

JOSE V. GAVILA (EB5AGV/EC5AAU) wrote:

Hello!

I am in need of some info about the 7S14 plug-in... is it worth $150 in
operating condition?. How does it performs?

Please, any information will be welcomed.

Thanks!

JOSE
----------------------------------------------------------------------
73 EB5AGV / EC5AAU - JOSE V. GAVILA
La Canyada - Valencia (SPAIN)

EB5AGV Vintage Radio Site: http://www.geocities.com/eb5agv

European Boatanchors List: http://groups.yahoo.com/group/euro_ba_swap

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



Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
To unsubscribe from this group, send an email to:
TekScopes-unsubscribe@egroups.com



Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/


Stan or Patricia Griffiths <w7ni@...>
 

In most sampling instruments I have encountered, signals start distorting when they
exceed about 2 volts in amplitude. Damage to the sampling diodes occurs around 5
volts and you never want to apply DC to the input of a sampler.

There are a couple of exceptions to this . . .

Stan
w7ni@easystreet.com

Don Black wrote:

Hi,
I haven't had any experience with sampling CROs but believe the plugins can
be damaged with input signals greater than 5 to 10 volts (depending on model). Be
careful to limit input signals as they're very difficult to obtain parts or
service.
Perhaps others have some comments on this.
Good Luck, Don Black.

Stan or Patricia Griffiths wrote:

My opinion is that a working and calibrated 7S14 that meets all of its
original specifications should be worth $150. The problem is that almost
nobody has the ability to determine if one is really working properly or
not. You have to have a very fast rise and clean pulse generator, an
amplitude calibrated 50 ohm voltage source, and a fast time mark generator at
a very minimum in order to get any idea if it really works correctly.

If it does not work correctly, it may be impossible to find the parts you
need to fix it. The most vulnerable parts are the sampling diodes and I
suspect they are impossible to find, but I have to admit I have not searched
for any. I am sure there are other critical, hard to find parts in the 7S14.

Does this unit come with a "money-back guarantee" . . . ?

Stan
w7ni@easystreet.com

JOSE V. GAVILA (EB5AGV/EC5AAU) wrote:

Hello!

I am in need of some info about the 7S14 plug-in... is it worth $150 in
operating condition?. How does it performs?

Please, any information will be welcomed.

Thanks!

JOSE
----------------------------------------------------------------------
73 EB5AGV / EC5AAU - JOSE V. GAVILA
La Canyada - Valencia (SPAIN)

EB5AGV Vintage Radio Site: http://www.geocities.com/eb5agv

European Boatanchors List: http://groups.yahoo.com/group/euro_ba_swap

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



Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
To unsubscribe from this group, send an email to:
TekScopes-unsubscribe@egroups.com



Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
To unsubscribe from this group, send an email to:
TekScopes-unsubscribe@egroups.com



Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/


dhuster@...
 

Sometimes, time-mark generators are overrated. The advantage of them
is that they make vertical marks for easily matching marks to
graticule lines. But if you need faster timing checks, you don't
need to be slaved to an older time-mark generator that won't give you
fast marks. As long as you have a signal generator and a counter (or
built-in counter on the generator), you can get accurate timing
references. A generator capable of 1 GHZ will give you
1ns/div "marks". And if you have a 100ps/div timebase, that only
means that you'll have a "mark" every 10 divisions. You don't HAVE
to have marks every division to calibrate, although it is nice to
check out linearity, of course. Many of the Hewlett-Packard
microwave generators can go higher yet.

I had a Navy chief who thought he knew everything tell me once that I
couldn't calibrate oscilloscopes if I didn't have a time-mark
generator. Pulease!


Stan or Patricia Griffiths <w7ni@...>
 

I hate to disagree, but the Navy Chief had a good point. The military, as
you know, tends to "go by the book". The book in this case is a Tek manual
and it specifies timemark generators.

But more important than that, standard timing measurements on scope screens
are made from the second graticule line to the ninth graticule line, ignoring
the first and last 10% of the sweep. How can you do this if you don't have
some reference mark at both of those points? A sinewave with one cycle
spread over the entire screen won't do it. You could, I suppose, set your
generator's frequency with the counter such that one cycle occupies 8
divisions on the scope screen . . . but even then, there is another problem.
Where the sinewave crosses the second and ninth graticule lines, it is
traversing the screen at a rather severe angle to those graticule lines.
This can lead to errors in viewing this measurement that are well beyond the
typical 2 or 3 percent specification of the the scope's timing.

This does not mean that WE can't make some very useful timing measurements on
scopes with counters and generators . . . we can! Most of us don't have to
worry about the stringent rules of a military metrology environment like that
Navy Chief certainly did.

Extremely fast scope sweep speeds is exactly why Tektronix developed the
concept of the "slewed edge" found in the CG551AP and later versions of that
scope calibrator. I prepared and presented a stand up presentation on the
"Tektronix Slewed Edge" at a metrology conference in LA in about 1979 when I
was the Tek TM500 Marketing guru in charge or marketing the CG551AP. The
slewed edge is an extremely noval idea on how to calibrate extremely fast
sweep speeds, even if you don't have the required bandwidth to view sinewaves
at those speeds.

Stan
w7ni@easystreet.com

dhuster@pb.k12.mo.us wrote:

Sometimes, time-mark generators are overrated. The advantage of them
is that they make vertical marks for easily matching marks to
graticule lines. But if you need faster timing checks, you don't
need to be slaved to an older time-mark generator that won't give you
fast marks. As long as you have a signal generator and a counter (or
built-in counter on the generator), you can get accurate timing
references. A generator capable of 1 GHZ will give you
1ns/div "marks". And if you have a 100ps/div timebase, that only
means that you'll have a "mark" every 10 divisions. You don't HAVE
to have marks every division to calibrate, although it is nice to
check out linearity, of course. Many of the Hewlett-Packard
microwave generators can go higher yet.

I had a Navy chief who thought he knew everything tell me once that I
couldn't calibrate oscilloscopes if I didn't have a time-mark
generator. Pulease!

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



Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/