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My 2753P Spectrum analyzer gave me the scare of my life.

I had not used the unit in about a month, but tonight I built
a filter and I had to see the response. I have a TR503
Tracking generator and both units are perfect
for checking filter bandwidth.

I had the 2753P on for about five minutes, and all of a sudden,
the display went nuts and all the front panel lights
wend black. The display still showed something but it was garbage.

All the front panel switches/buttons were dead except
the Peak/Average control which still managed to move the
averaging line up/down on the screen. Everything else was dead!

So I turned the machine off, unplugged the TR503, and put
50Ohm terminators on the 1stLo, 2ndLo SMA outputs.

I turned the machine on again, after 10 minutes, and all was
dead again. At this point, you can imagine how I felt.
There it was, my very nice (and expensive) spectrum analyzer
dead as a doornail.

I figured, here comes a very long troubleshooting session.
So I take the instrument down, and take out all the panels.
I don't have the Schematic Manual (That is volume two)
so I was really worried that I would be without my spectrum
analyzer for a very long time.

So I re-seat all the cards, and still nothing. I check the output
of the calibrator on my scope, and it was fine.

As a last resort, I moved the Time/Div knob from "AUTO"
to 1ms. Guess what..... The front panel flashed!!!!!!!!!
I left the Time/Div knob to 1ms, and I turned off the unit.

When I turned on the unit, all the front panel controls
became functional and the unit came back to life.
But still no signal on the display.

I figured the front end had kicked the bucket. I tried the
calibrate procedure and it failed right away.

At this point I became very depressed. I don't think
the front-end components of 2753P are still made.
However, by mistake I ran the calibration routine
with the Time/Div on 1ms and when it finished,
I could see some response on the display.

Sure enough, when I put the Time/Div back to
Auto, and ran the calibration routine, it passed.
The machine is now fully operational.

I have no idea what happened, and no idea
how it was fixed. I am just grateful that my spectrum
analyzer is alive again. I felt "blind" without it.

Sorry for the long post.

George Hrysanthopoulos, N2FGX

I'm at the $2 windows saying it doesn't last 3..





Regards,



don f.

KR4XH

I generally turn down the intensity quite a bit when not viewing the trace. I watch for that on some of the older tube scopes..because if stops sweeping trace could end up as a dot.



Mark Anton, Owner
Heights TV & VCR Service
3946 Central Ave. NE
Columbia Heights MN, 55421

Phone is 763-789-1767

(area code formerly 612)





----Original Message Follows----
From: "Craig Sawyers" <c.sawyers@...>
To: <tekscopes@...>
Subject: RE: [TekScopes] Is it advisable to turn intensity down when scope is idle (but displaying a signal) to preserve CRT?
Date: Wed, 3 Mar 2004 23:47:51 -0000

Should the scope intensity be turned down to some degree or all the way
during this programming time to avoid phosphor degradation, or perhaps
should the scope be turned off during these intervals?

I usually turn down the intensity on the scope right down if I'm doing
something else for a while. But then again, I usually run at a fairly low
brightness anyway - there simply doesn't seem to be the need to crank it up
too far; you just need a clear trace, not a retina burning event.

Craig

_________________________________________________________________
Store more e-mails with MSN Hotmail Extra Storage ? 4 plans to choose from!

Grobbins got a virus!
Grobbins got a virus!
Neener, neener, neener!

Well, it is about time for a little public humiliation of the "no-
clues" that click on an attachment.

Unfortunately, Grobbins has helped to propagate a potentially
harmful virus/worm because he:

1. Did not have antivirus software up-to-date, AND
2. Opened an unsafe attachment from a source he did not really
recognize.

Sorry, but if we are going to limit these virus/worm attacks, we are
all going to have to be smarter. For a techie to fall for one of
these is embarrassing.

(Minor sympathy:) Some of these worms have been masquerading as
email bounces. It is very tempting to open the attachment, to see
which of your messages did not get delivered. CHECK THE TYPE! If
it is not .eml, it is not email.

OK, who else wants to be humiliated?

-Peer-pressure panderer, Howard

P.S. Grobbins probably doesn't even know he has started this
thread. But if he has an excuse other than "sorry", we could
probably all learn from it. (Hint, hint :)

P.P.S. Who wants to bet the moderator will trash this thread in
about 2 hours? I do! The only topical connection is that we are
all supposedly a little more tech-savy than the median computer user.

I think i might have mentioned before on this list, an item that works well for a screen filter is lighting gel material. You can pick the color....use one that is close to the color of the trace. A musical intrument repair shop should possibly have some. The only to be careful of is not too get one that is too opaque. Then you would have to turn up intensity farther than needed to view the trace. I have used gel material on several scopes now and works well. It isnt just for looks either...the reason it is there is to provide a higher contrast trace. vs seeing a white background.

Maybe someone else might know of where you could get a cover.

Mark Anton, Owner
Heights TV & VCR Service
3946 Central Ave. NE
Columbia Heights MN, 55421

Phone is 763-789-1767

(area code formerly 612)





----Original Message Follows----
From: timothy.urban@...
To: <TekScopes@...>
Subject: [TekScopes] 475A filter, protective cap availability?
Date: Wed, 3 Mar 2004 08:21:34 -0500

Got a nice working 475A, would like to replace the original blue/green CRT
filter with a nice sharp new one. Ar they commonly available?

Also need the protective cap that fits over the face of the scope - what
do these go for, and are there any better sources for them?

Thanks

Tim
N5IIT

_________________________________________________________________
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Please have a look at the attached file.

RG8/U is still alive at Belden in the form 'RG8A/U Type', but being
referenced to MIL-C-17D can not be too far off. At the first glance, RG213U
appears to be similar, but there must be some minor difference or there
would not be another RG number. You can look at the details at Belden's
web site:
.
That is cross reference for RG to current cables and then you can find
complete catalog at:


Regards

Miroslav Pokorni

But it will have to be surplused first before I can even have a shot
at it. Surplused to me means big black hole. Damn.

Ask NR1DX, He Often Has The Disc On His E-Bay Auction. Just Search By Single Seller, And Enter NR1DX. Has Quality Scans Available.

Greyhawk

With all the talk of TEK samplers and the mention of the 7S14, I wonder what are we 7S14 owners to do these days when it comes to replacing the bias batteries in the 7S14? I gather that the merc oxide batteries originally spec'ed are no longer available. Is the 1.35V merc oxide batt voltage that strict a spec in the 7S14?

The only kind of mercury cells I can find can be seen at


I have ordered cells from here before for my older Rollei SLR light meter. The cells I received appeared to be of Mexican origin.

These appear to be available for a short time. Perhaps an button cell adapter is in order.

The loss of mercury cells has caused an impact on both the older camera and the Bulova Accutron wristwatch collector community (the watches use #343 or #387 cells, which have been unobtainable for several years now). I will spare the list from listening to a rant about environmentalists ;). Your tax dollars at work.

I refurbished an old Simco electrostatic voltmeter that used mercury cells for both a reference and a differential opamp supply. I ended up making some postage stamp PCBs incorporating some Linear Technology micropower regulators that allowed me to generate the needed voltages from alkaline cells.

-Dan

I have two of these units. One has a bad battery
but the other one is still working fine after 25 years!
Dennis

Hi Bill,

I generally use just about any random piece of RG58 that is 2-6 feet long
for these applications. It really does not seem to make a lot of
difference. It will make more difference when you calibrate scopes above
100 MHz bandwidth.

Stan
w7ni@...

At 02:43 PM 3/4/2004 , Michael Dunn wrote:

Does anyone have a digitized manual...?

Yes.


newell

Does anyone have a digitized manual...?

At 12:39 PM 3/4/2004 , vollumscope wrote:

With all the talk of TEK samplers and the mention of the 7S14, I
wonder what are we 7S14 owners to do these days when it comes to
replacing the bias batteries in the 7S14?

Funny, I was going to ask if there were any symptoms of weak cells.
Anything to watch out for?


newell

Howdy all-

With all the talk of TEK samplers and the mention of the 7S14, I
wonder what are we 7S14 owners to do these days when it comes to
replacing the bias batteries in the 7S14?

I gather that the merc oxide batteries originally spec'ed are no
longer available. Is the 1.35V merc oxide batt voltage that strict a
spec in the 7S14?

Thoughts?


-Vollumscope

www.caplugs.com

www.mocap.com

Dan Tulloss
Senior Metrologist
National Test Equipment, Inc.
760-639-1700
760-639-1799 Fax
www.nationaltestequipment.com

The manual for the Tektronix 453 oscilloscope calls
for a specific length of coax between the calibration
instruments and the oscilloscope, i.e. 42 inches. I
noticed in the manual for the 191 Constant Amplitiude
Signal Generator instuctions to use RG8A/U coax. I
have been told RG213/U is the direct replacement for
this coax now. Is this a fact?

What do you all use?
Thanks,
Bill

=====
Bill Smith KO4NR

__________________________________
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Hi, all;

Where do those brightly-colored BNC dust-caps come from?
Seen a lot on e-bay and I could use some for some stuff
I have in storage.
many thanks
Tim.

This link should work
<>.

Don Black.

Jeff W wrote: