Re: Trying to understand the 453 calibrator

Colin Herbert

Aha! I should have looked more closely. The calibration BNC on the front panel is indeed a voltage calibration and is switchable between 1V and 0.1V by means of a switch on the side-panel. Silly me!

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Colin Herbert via groups.io
Sent: 03 August 2020 19:22
To: TekScopes@groups.io
Subject: Re: [TekScopes] Trying to understand the 453 calibrator

There is a bit of a clue in that the calibration loop on the right-hand side is marked with an arrow pointing left and the words "5mA" followed by a square-wave. The calibration BNC on the front panel is marked "1 kHz". This should lead one to think that the BNC on the front-panel is for Time/Div calibration and the loop on the right side is for Current/Div calibration. I will have to look at how the "1kHz" is generated to see if it really is accurate (most of these are not that accurate).
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Richard P via groups.io
Sent: 03 August 2020 19:02
To: TekScopes@groups.io
Subject: Re: [TekScopes] Trying to understand the 453 calibrator

Harvey (and all),

Yeah, my loop is directly grounded, so I will get my calibration voltage signal from the BNC on the front panel. Works fine.

R

Re: Trying to understand the 453 calibrator

Colin Herbert

There is a bit of a clue in that the calibration loop on the right-hand side is marked with an arrow pointing left and the words "5mA" followed by a square-wave. The calibration BNC on the front panel is marked "1 kHz". This should lead one to think that the BNC on the front-panel is for Time/Div calibration and the loop on the right side is for Current/Div calibration. I will have to look at how the "1kHz" is generated to see if it really is accurate (most of these are not that accurate).
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Richard P via groups.io
Sent: 03 August 2020 19:02
To: TekScopes@groups.io
Subject: Re: [TekScopes] Trying to understand the 453 calibrator

Harvey (and all),

Yeah, my loop is directly grounded, so I will get my calibration voltage signal from the BNC on the front panel. Works fine.

R

Re: Trying to understand the 453 calibrator

Richard P

Harvey (and all),

Yeah, my loop is directly grounded, so I will get my calibration voltage signal from the BNC on the front panel. Works fine.

R

Re: Trying to understand the 453 calibrator

Harvey White

It depends on the scope.

On a 7000 series scope, the bar is insulated and there's a separate calibrator BNC.  Use whichever you need.

The closest I can get to a 453 is one of my 468 scopes, where I didn't see a calibrator BNC (very quick look), did see a bare wire loop.  That wire loop was labeled with a current and voltage.  You can get that if the wire loop goes to the source, then is grounded through a current limiting resistor for the current probe.  I think that the voltage was roughly 200 mv p-p.

If the loop is directly grounded, all it can provide is a current, and you'll find the calibrator output elsewhere.

Harvey

On 8/3/2020 1:25 PM, Richard P via groups.io wrote:
Ahhhh. That’s above my pay grade, I suppose. I just thought you used the little bar to compensate a basic probe.

Re: Trying to understand the 453 calibrator

Harvey White

It's a current loop for calibrating current probes.

Harvey

On 8/3/2020 1:12 PM, Richard P via groups.io wrote:
I’ve always been able to get a good 1 kc square wave from the front panel BNC calibrator output. Works ok for compensating a probe. But I never could get the 1 kc signal from the probe loop on the side panel. Today, I verified the signal is being delivered to one side of the loop through parallel resistors equaling 20 ohms, in agreement with the schematic. But since the other side of the loop is tied to ground, also in agreement with the schematic, it seems to me the square wave is going to ground, and hence, that is why I have never seen any square wave on the loop. Never, ever. The loop is a ground. How is this supposed to work? Thanks.

Richard

Re: Trying to understand the 453 calibrator

SCMenasian

It's to calibrate a current probe. A calibrated current square wave is in the loop. A clip-on current probe should pick it up.

Re: Stuck switches on 453

Stephen

If this is of any help, I had something similar on a 7B71, 7000 series time base plug-in.
The VAR didn’t want to move at all. It was completely stuck. I ended up de-soldering the pot and freeing it from the shaft extension a bit. It turns out it was pushed way too much into it and, as a result, wasn’t moving. That wasn’t easy, but now it’s completely free, and working as it should.

I don’t know how yours is mounted, but I hope this help...

Re: Trying to understand the 453 calibrator

Richard P

Ahhhh. That’s above my pay grade, I suppose. I just thought you used the little bar to compensate a basic probe.

Re: Trying to understand the 453 calibrator

Bob Albert

It's not delivering a square wave of voltage.  It's a current loop for calibrating a current probe.
Bob

On Monday, August 3, 2020, 10:12:11 AM PDT, Richard P via groups.io <wb5nen=yahoo.com@groups.io> wrote:

I’ve always been able to get a good 1 kc square wave from the front panel BNC calibrator output. Works ok for compensating a probe. But I never could get the 1 kc signal from the probe loop on the side panel. Today, I verified the signal is being delivered to one side of the loop through parallel resistors equaling 20 ohms, in agreement with the schematic. But since the other side of the loop is tied to ground, also in agreement with the schematic, it seems to me the square wave is going to ground, and hence, that is why I have never seen any square wave on the loop. Never, ever.  The loop is a ground. How is this supposed to work? Thanks.

Richard

Re: Why would you do this?

snapdiode

I have a CombBind machine and spines in any case, it's just the odd cropping of the pictures that made me suspicious.
Turns out the spine is pretty good and a very clever and handsome person bought the manual.
Oh and he smells good too.

Trying to understand the 453 calibrator

Richard P

I’ve always been able to get a good 1 kc square wave from the front panel BNC calibrator output. Works ok for compensating a probe. But I never could get the 1 kc signal from the probe loop on the side panel. Today, I verified the signal is being delivered to one side of the loop through parallel resistors equaling 20 ohms, in agreement with the schematic. But since the other side of the loop is tied to ground, also in agreement with the schematic, it seems to me the square wave is going to ground, and hence, that is why I have never seen any square wave on the loop. Never, ever. The loop is a ground. How is this supposed to work? Thanks.

Richard

Re: Stuck switches on 453

Richard P

I barely managed to free up (a little) one of the two stuck potentiometer/switching knobs on the variable time/division control. (I see in an earlier post or two that I mistakenly started started saying it was the volts/div controls that were stuck. Wrong. It is time/div that are stuck. Regardless, it was a similar problem. It was stuck. Apologies.) Anyway, the “Uncal” light is off and things are working acceptably. I thank everyone for help. But boy, these guys are stuck! I can live with this.

Richard

Re: TM500 DM511 Digital Multimeter Service Manual?

Jared Cabot

On Tue, Aug 4, 2020 at 12:33 AM, Ken Eckert wrote:

That's the one! Much thanks! :)

Re: TM500 DM511 Digital Multimeter Service Manual?

Ken Eckert

Re: TM500 DM511 Digital Multimeter Service Manual?

Stephen

On Mon, Aug 3, 2020 at 03:51 AM, Jared Cabot wrote:
Unfortunately that is just the user manual, there's no service info in there
like calibration procedures, troubleshooting, parts list or schematics etc.
Maybe someone here has an original one, and would be willing to scan it for you for a small fee.
Or, if it’s not urgent, you could always wait for one to pops up on eBay or another auction site. I don’t know how often they do, though.
Sorry I can’t be of anymore help.

Re: TM500 DM511 Digital Multimeter Service Manual?

Dave Daniel

https://www.ebay.com/itm/TEKTRONIX-Ops-Service-Manuals-for-DM511-DM5110-Programmable-Digitlal-Multimeter-/370469694062

There are pobably others out there.

I assume you’ve checked Artek manuals?

http://artekmanuals.com/

They are not free, but what you get is a very high-quality PDF.

DaveD

On Aug 3, 2020, at 10:51, Jared Cabot via groups.io <jaredcabot=protonmail.com@groups.io> wrote:

On Mon, Aug 3, 2020 at 11:38 PM, Stephen wrote:

http://w140.com/tek_dm5110_dm511_user.pdf

Unfortunately that is just the user manual, there's no service info in there like calibration procedures, troubleshooting, parts list or schematics etc.

Re: TM500 DM511 Digital Multimeter Service Manual?

Dave Daniel

That is true.

There are also the Davmar, KO4BB, Barrytech, kahrs.us and other sites (my apologies to the owners of those sites for my declining memory) which sometimes offer different information, including non-Tektronix instrument resources.

DaveD

On Aug 3, 2020, at 10:35, Colin Herbert via groups.io <colingherbert=blueyonder.co.uk@groups.io> wrote:

I was about to link to that! TekWiki is a resource everyone interested in Tektronix gear should be aware of. It won't protect you from Coronavirus or cure your ingrowing toenails, but it does almost everything else. Enjoy it.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Dave Daniel
Sent: 03 August 2020 15:26
To: TekScopes@groups.io
Subject: Re: [TekScopes] TM500 DM511 Digital Multimeter Service Manual?

http://w140.com/tekwiki/wiki/DM511

DaveD

On 8/3/2020 10:24 AM, Jared Cabot via groups.io wrote:
Hi,

I'm looking for a service manual for a TM500 module DM511 multimeter, does anyone know where I can download this from?

Thanks!

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Re: TM500 DM511 Digital Multimeter Service Manual?

Jared Cabot

On Mon, Aug 3, 2020 at 11:38 PM, Stephen wrote:

http://w140.com/tek_dm5110_dm511_user.pdf

Unfortunately that is just the user manual, there's no service info in there like calibration procedures, troubleshooting, parts list or schematics etc.

Re: TM500 DM511 Digital Multimeter Service Manual?

Stephen

Re: TM500 DM511 Digital Multimeter Service Manual?

Colin Herbert

I was about to link to that! TekWiki is a resource everyone interested in Tektronix gear should be aware of. It won't protect you from Coronavirus or cure your ingrowing toenails, but it does almost everything else. Enjoy it.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Dave Daniel
Sent: 03 August 2020 15:26
To: TekScopes@groups.io
Subject: Re: [TekScopes] TM500 DM511 Digital Multimeter Service Manual?

http://w140.com/tekwiki/wiki/DM511

DaveD

On 8/3/2020 10:24 AM, Jared Cabot via groups.io wrote:
Hi,

I'm looking for a service manual for a TM500 module DM511 multimeter, does anyone know where I can download this from?

Thanks!

--
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