Date   
Re: TDS3032 Loosing its GPIB Address

 

On Mon, Sep 3, 2018 at 04:43 PM, David Kuhn wrote:


Is there a lithium battery in the scope or in the I/O Module (I have the
I/O module with VGA, RS232 and GPIB).
There's no memory in the module but there is a DALLAS DS1742W-150 Timekeeping RAM
on the main board in the scope.

Does your scope have the latest firmware ?
Is the date & time clock working as expected ?

/Håkan

J16 sensors

Mark Kahrs
 

A friend acquired a J16 but the sensor is, in his words, "toast".

Any thoughts on replacing such a beast?

Re: J16 sensors

Pete Lancashire
 

What do you mean by the sensor ?

Is it the actual photo pick up device or it is the sensor assembly is not
working ?

On Mon, Sep 3, 2018, 12:23 PM Mark Kahrs <mark.kahrs@...> wrote:

A friend acquired a J16 but the sensor is, in his words, "toast".

Any thoughts on replacing such a beast?



Re: J16 sensors

Mark Kahrs
 

And I quote:

"I went through the prescribed procedure in the manual to inject an
artificial
DC signal into the 15 pin connector on the readout unit and got
a sensible number, but the whole thing goes flakey when I then re-attach
the sensor dongle.
The sensor itself, in my case, is a square puck with no active electronics.
It appears to be a silicon photodiode behind an optical filter window.
J6511, I think."

On Mon, Sep 3, 2018 at 3:25 PM Pete Lancashire <xyzzypdx@...> wrote:

What do you mean by the sensor ?

Is it the actual photo pick up device or it is the sensor assembly is not
working ?

On Mon, Sep 3, 2018, 12:23 PM Mark Kahrs <mark.kahrs@...> wrote:

A friend acquired a J16 but the sensor is, in his words, "toast".

Any thoughts on replacing such a beast?





Re: J16 sensors

Adrian
 

There are a number of sensor heads available for this instrument, I have several of them here. They come in both 'imperial' and 'metric' units.

In terms of electronic components they only have a photo diode, a pot and a fixed resistor in them.

In terms of optical components it's mostly just a filter and baffles to collimate the incoming light I think.

The pot and resistor set the gain in the main instrument thus the calibration is done in the sensor head.

We need to know which head and which bit is toasted to help much further!

Adrian

On 9/3/2018 8:23 PM, Mark Kahrs wrote:
A friend acquired a J16 but the sensor is, in his words, "toast".

Any thoughts on replacing such a beast?

Re: J16 sensors

Mark Kahrs
 

J6511.

He says it's the sensor and I believe him. I suspect this may be made of
unobtanium.

On Mon, Sep 3, 2018 at 3:43 PM Adrian <Adrian@...> wrote:

There are a number of sensor heads available for this instrument, I have
several of them here. They come in both 'imperial' and 'metric' units.

In terms of electronic components they only have a photo diode, a pot
and a fixed resistor in them.

In terms of optical components it's mostly just a filter and baffles to
collimate the incoming light I think.

The pot and resistor set the gain in the main instrument thus the
calibration is done in the sensor head.

We need to know which head and which bit is toasted to help much further!

Adrian


On 9/3/2018 8:23 PM, Mark Kahrs wrote:
A friend acquired a J16 but the sensor is, in his words, "toast".

Any thoughts on replacing such a beast?





Re: J16 sensors

Adrian
 

As I say, the gain is set in the sensor head so it's in the feedback loop of the main instrument, I have a 6501 photopic head but don't have the 6511 (cosine corrected) version. I'll be surprised if there isn't a cal pot under a sticker somewhere. An iffy pot will also cause what he sees (I've had that) but if it is the diode then there are things out there that will work.

 I've made a couple of slightly special (mechanically) heads which seem to work fine using currently available diodes. He'll need to get a look inside but most likely the diode is a TO5 wide bandwidth thing with a separate filter to do the matching to the photopic curve with everything behind a clever lens.

Adrian

On 9/3/2018 8:52 PM, Mark Kahrs wrote:
J6511.

He says it's the sensor and I believe him. I suspect this may be made of
unobtanium.



On Mon, Sep 3, 2018 at 3:43 PM Adrian <Adrian@...> wrote:

There are a number of sensor heads available for this instrument, I have
several of them here. They come in both 'imperial' and 'metric' units.

In terms of electronic components they only have a photo diode, a pot
and a fixed resistor in them.

In terms of optical components it's mostly just a filter and baffles to
collimate the incoming light I think.

The pot and resistor set the gain in the main instrument thus the
calibration is done in the sensor head.

We need to know which head and which bit is toasted to help much further!

Adrian


On 9/3/2018 8:23 PM, Mark Kahrs wrote:
A friend acquired a J16 but the sensor is, in his words, "toast".

Any thoughts on replacing such a beast?




Re: Tek 466 analog storage

Paul B.
 

Thanks very much, Roger. You can go away on your holiday; don't worry about trying to fix this!!!

Re: J16 sensors

Mark Kahrs
 

Yes indeed, it's the aforementioned TO-5. What are your suggested
replacements?

On Mon, Sep 3, 2018 at 4:17 PM Adrian <Adrian@...> wrote:

As I say, the gain is set in the sensor head so it's in the feedback
loop of the main instrument, I have a 6501 photopic head but don't have
the 6511 (cosine corrected) version. I'll be surprised if there isn't a
cal pot under a sticker somewhere. An iffy pot will also cause what he
sees (I've had that) but if it is the diode then there are things out
there that will work.

I've made a couple of slightly special (mechanically) heads which seem
to work fine using currently available diodes. He'll need to get a look
inside but most likely the diode is a TO5 wide bandwidth thing with a
separate filter to do the matching to the photopic curve with everything
behind a clever lens.

Adrian
On 9/3/2018 8:52 PM, Mark Kahrs wrote:
J6511.

He says it's the sensor and I believe him. I suspect this may be made of
unobtanium.



On Mon, Sep 3, 2018 at 3:43 PM Adrian <Adrian@...> wrote:

There are a number of sensor heads available for this instrument, I have
several of them here. They come in both 'imperial' and 'metric' units.

In terms of electronic components they only have a photo diode, a pot
and a fixed resistor in them.

In terms of optical components it's mostly just a filter and baffles to
collimate the incoming light I think.

The pot and resistor set the gain in the main instrument thus the
calibration is done in the sensor head.

We need to know which head and which bit is toasted to help much
further!

Adrian


On 9/3/2018 8:23 PM, Mark Kahrs wrote:
A friend acquired a J16 but the sensor is, in his words, "toast".

Any thoughts on replacing such a beast?







Tek 495p Deflection

Joe Rocci
 

Yesterday I was using my 495P. I walked away for about an hour and when I returned there was just a bright spot in the center of the screen - no vertical or horizontal deflection. It seems to me like a deflection amp power supply problem, but I wanted some sage information before digging into it.

Joe

Re: TG501 20ns 10ns 5ns

Kerry Burns
 

Hello Petru

I've put a couple of screenshots in the photos section (under TG501 5ns 2ns). The amplitude of the 5ns waveform is 1.24v pp and well within spec. The 2ns is 0.9v pp. this appears below spec, but this is to be expected on a 350 Mhz scope. I don't get a waveform on the 2456A for 1ns, but this most likely due to the bandwidth limitation, rather than indicating that the TG501 doesn't work on this range. I'll have to wait until I have a working 1GHz scope before I can check this.

Regards

Kerry

Re: Tek 495p Deflection

Bob Koller
 

As always, check the power supply voltages, and ripple first. Easy to do, the test points are right on to of the uncased instrument, and labeled too!

Also, check the fuses under the little cover at the top of the power supply.

Re: TG501 20ns 10ns 5ns

Siggi
 

And here's the album link for posterity:
https://groups.io/g/TekScopes/album?id=69365.

On Tue, 4 Sep 2018 at 07:43 <kburns@...> wrote:

Hello Petru

I've put a couple of screenshots in the photos section (under TG501 5ns
2ns). The amplitude of the 5ns waveform is 1.24v pp and well within
spec. The 2ns is 0.9v pp. this appears below spec, but this is to be
expected on a 350 Mhz scope. I don't get a waveform on the 2456A for 1ns,
but this most likely due to the bandwidth limitation, rather than
indicating that the TG501 doesn't work on this range. I'll have to wait
until I have a working 1GHz scope before I can check this.

Regards

Kerry



Re: J16 sensors

Adrian
 

If keeping the existing photopic filter (I'm assuming there is one) then some research into the response of the current diode will be needed. I think an alternative might be to remove the current filter  and use either something like a Vishay BPW21R which has a filter built in and may be accurate enough, or replace both with a matched diode/filter pair from someone like Thorlabs but that can be pricey!

On 9/4/2018 1:11 AM, Mark Kahrs wrote:
Yes indeed, it's the aforementioned TO-5. What are your suggested
replacements?



On Mon, Sep 3, 2018 at 4:17 PM Adrian <Adrian@...> wrote:

As I say, the gain is set in the sensor head so it's in the feedback
loop of the main instrument, I have a 6501 photopic head but don't have
the 6511 (cosine corrected) version. I'll be surprised if there isn't a
cal pot under a sticker somewhere. An iffy pot will also cause what he
sees (I've had that) but if it is the diode then there are things out
there that will work.

I've made a couple of slightly special (mechanically) heads which seem
to work fine using currently available diodes. He'll need to get a look
inside but most likely the diode is a TO5 wide bandwidth thing with a
separate filter to do the matching to the photopic curve with everything
behind a clever lens.

Adrian
On 9/3/2018 8:52 PM, Mark Kahrs wrote:
J6511.

He says it's the sensor and I believe him. I suspect this may be made of
unobtanium.



On Mon, Sep 3, 2018 at 3:43 PM Adrian <Adrian@...> wrote:

There are a number of sensor heads available for this instrument, I have
several of them here. They come in both 'imperial' and 'metric' units.

In terms of electronic components they only have a photo diode, a pot
and a fixed resistor in them.

In terms of optical components it's mostly just a filter and baffles to
collimate the incoming light I think.

The pot and resistor set the gain in the main instrument thus the
calibration is done in the sensor head.

We need to know which head and which bit is toasted to help much
further!
Adrian


On 9/3/2018 8:23 PM, Mark Kahrs wrote:
A friend acquired a J16 but the sensor is, in his words, "toast".

Any thoughts on replacing such a beast?





Re: TG501 20ns 10ns 5ns

Petru Ulici
 

Thank you very much. I was not sure if my TG501 is in the parameters, I did not have a 1GHz oscilloscope. 
Now I can compare with the pictures posted. 
Best wish.

Petru

On Tuesday, September 4, 2018, 2:43:17 PM GMT+3, kburns@... <kburns@...> wrote:

Hello Petru

I've put a couple of screenshots in the photos section (under TG501 5ns 2ns).  The amplitude of the 5ns waveform is 1.24v pp  and well within spec.  The 2ns is 0.9v pp. this appears below spec, but this is to be expected on a 350 Mhz scope.  I don't get a waveform on the 2456A for 1ns, but this most likely due to the bandwidth limitation, rather than indicating that the TG501 doesn't work on this range.  I'll have to wait until I have a working 1GHz scope before I can check this.

Regards

Kerry

Re: J16 sensors

Daniel Koller
 

Hi Folks,
   I just caught this thread because of the word "sensor" in the subject line - "photo-sensor" would have been more helpful, but I am glad I read the message, as it is a subject of interest (and it's come up from time to time as an off-topic conversation when we drift into debates about LEDs vs. incandescents!).
   I did not know that Tek made photo-optical sensors.   How common are these?   In particular, what do the PHOTOPIC sensors (i.e. those conforming to the CIE photopic curve, which is a modeled response of the average human eye to wavelength) go for on e-bay?  Can one even find the sensors?
   In direct response to Adrian, that Vishay sensor (BPW21R) won't work.  I have considered that one for light measurments.  Take a look at p. 3 of the datasheet here: https://www.vishay.com/docs/81519/bpw21r.pdf  At the bottom you see a comparison of the photo response of the Vishay photodiode to the CIE curve.   Those responses aren't even close.  I don't see how they can get away with calling that a CIE response.  Sure, at 550 nm, you can calibrate the sensor to give you close results with incandescent lighting.  But then consider a multi-spectral light source such as a white-light LED.  Typically they are driven by a UV or blue laser with a very strong peak somewhere around 450 nm.   The error there will be huge, and will seriously affect the accuracy of the measurement.
  I have an interest in verifying the "lumen output" claims of off-the-shelf, Chinese made LEDs for 110V lighting, so I poke around and search for sensors every once in a while.  I was very pleased to find this one, from TI:  http://www.ti.com/lit/ds/symlink/opt3001.pdf   Look at the response curve on p.1.   Now *THAT* is a photopic sensor!   The only problem is that it (and all its kin) have a digital (I2C) output.   Not having an analog output complicates things a bit.
  I suppose if it really needed to fit in the original Tek package, one could use an SOT-package Microchip processor to talk I2C to the TI sensor, pulse-width modulate the output and resistively divide down to mV to get something that mimics a photodiode, albeit ground-referenced and with an extra wire (for Vcc).  But it would have a photopic curve.   
  But how accurate was the original Tek photopic response, AND what were the filters made out of?   If plastic, there's a chance they have drifted in color with age, and the response is no longer photopic....Ah.  Some of my questions are answered here:  https://www.atecorp.com/atecorp/media/pdfs/data-sheets/tektronix-j16_datasheet.pdf   So those Tek probes were pretty damned good.   Ok, now I want a J6523 (photopic, 1 degree acceptance angle), and a J6502-A (flat)!
 Dan

On Tuesday, September 4, 2018, 11:54:44 AM EDT, Adrian <Adrian@...> wrote:

If keeping the existing photopic filter (I'm assuming there is one) then
some research into the response of the current diode will be needed. I
think an alternative might be to remove the current filter  and use
either something like a Vishay BPW21R which has a filter built in and
may be accurate enough, or replace both with a matched diode/filter pair
from someone like Thorlabs but that can be pricey!


On 9/4/2018 1:11 AM, Mark Kahrs wrote:
Yes indeed, it's the aforementioned TO-5.  What are your suggested
replacements?



On Mon, Sep 3, 2018 at 4:17 PM Adrian <Adrian@...> wrote:

As I say, the gain is set in the sensor head so it's in the feedback
loop of the main instrument, I have a 6501 photopic head but don't have
the 6511 (cosine corrected) version. I'll be surprised if there isn't a
cal pot under a sticker somewhere. An iffy pot will also cause what he
sees (I've had that) but if it is the diode then there are things out
there that will work.

    I've made a couple of slightly special (mechanically) heads which seem
to work fine using currently available diodes. He'll need to get a look
inside but most likely the diode is a TO5 wide bandwidth thing with a
separate filter to do the matching to the photopic curve with everything
behind a clever lens.

Adrian
On 9/3/2018 8:52 PM, Mark Kahrs wrote:
J6511.

He says it's the sensor and I believe him.  I suspect this may be made of
unobtanium.



On Mon, Sep 3, 2018 at 3:43 PM Adrian <Adrian@...> wrote:

There are a number of sensor heads available for this instrument, I have
several of them here. They come in both 'imperial' and 'metric' units.

In terms of electronic components they only have a photo diode, a pot
and a fixed resistor in them.

In terms of optical components it's mostly just a filter and baffles to
collimate the incoming light I think.

The pot and resistor set the gain in the main instrument thus the
calibration is done in the sensor head.

We need to know which head and which bit is toasted to help much
further!
Adrian


On 9/3/2018 8:23 PM, Mark Kahrs wrote:
A friend acquired a J16 but the sensor is, in his words, "toast".

Any thoughts on replacing such a beast?





Re: J16 sensors

Adrian
 

Hi Daniel,

Quick response as it's getting a bit late this side of the pond but yes, the Tek J16 and it's range of sensors is pretty good and the instrument itself is nice and easy to fix too!

I have a number of them - both nominally 'imperial' and 'metric' although from what I've seen they are the same, just the front panel printing is different (look at the gain push-button labels!) and the residual tweaking is done within the heads. I have a range of the sensors (including a J6523) too. All picked up over the last few years for almost nothing on a well known auction site. The J6523 was a real find - 28 USD and still sealed up in it's US military stores packing - works very nicely though has some light-leaks from the rear panel to the sensor I found when looking at low NVIS type levels.

Battery packs tend to be old and tired but NiMH sub-c cells fit very nicely and because it has an external charger that is easy too. My main use so far has been pre-compliance checks on aircraft displays and the numbers I get are not far from the test house results when we spend the big bucks for 'proper' tests.

One tip if you have an early instrument, swap all the socketed 74 TTL for LS and you about double the battery life!

Take your point about the Vishay part which is why I added the accuracy rider, the whole CIE curve and how it applies with LEDs vs Incandescent and a human eye seems to a non-expert (me!) a bit of a mess anyway?

Adrian

On 9/4/2018 9:52 PM, Daniel Koller via Groups.Io wrote:
Hi Folks,
   I just caught this thread because of the word "sensor" in the subject line - "photo-sensor" would have been more helpful, but I am glad I read the message, as it is a subject of interest (and it's come up from time to time as an off-topic conversation when we drift into debates about LEDs vs. incandescents!).
   I did not know that Tek made photo-optical sensors.   How common are these?   In particular, what do the PHOTOPIC sensors (i.e. those conforming to the CIE photopic curve, which is a modeled response of the average human eye to wavelength) go for on e-bay?  Can one even find the sensors?
   In direct response to Adrian, that Vishay sensor (BPW21R) won't work.  I have considered that one for light measurments.  Take a look at p. 3 of the datasheet here: https://www.vishay.com/docs/81519/bpw21r.pdf  At the bottom you see a comparison of the photo response of the Vishay photodiode to the CIE curve.   Those responses aren't even close.  I don't see how they can get away with calling that a CIE response.  Sure, at 550 nm, you can calibrate the sensor to give you close results with incandescent lighting.  But then consider a multi-spectral light source such as a white-light LED.  Typically they are driven by a UV or blue laser with a very strong peak somewhere around 450 nm.   The error there will be huge, and will seriously affect the accuracy of the measurement.
  I have an interest in verifying the "lumen output" claims of off-the-shelf, Chinese made LEDs for 110V lighting, so I poke around and search for sensors every once in a while.  I was very pleased to find this one, from TI:  http://www.ti.com/lit/ds/symlink/opt3001.pdf   Look at the response curve on p.1.   Now *THAT* is a photopic sensor!   The only problem is that it (and all its kin) have a digital (I2C) output.   Not having an analog output complicates things a bit.
  I suppose if it really needed to fit in the original Tek package, one could use an SOT-package Microchip processor to talk I2C to the TI sensor, pulse-width modulate the output and resistively divide down to mV to get something that mimics a photodiode, albeit ground-referenced and with an extra wire (for Vcc).  But it would have a photopic curve.
  But how accurate was the original Tek photopic response, AND what were the filters made out of?   If plastic, there's a chance they have drifted in color with age, and the response is no longer photopic....Ah.  Some of my questions are answered here:  https://www.atecorp.com/atecorp/media/pdfs/data-sheets/tektronix-j16_datasheet.pdf   So those Tek probes were pretty damned good.   Ok, now I want a J6523 (photopic, 1 degree acceptance angle), and a J6502-A (flat)!
 Dan
On Tuesday, September 4, 2018, 11:54:44 AM EDT, Adrian <Adrian@...> wrote:
If keeping the existing photopic filter (I'm assuming there is one) then
some research into the response of the current diode will be needed. I
think an alternative might be to remove the current filter  and use
either something like a Vishay BPW21R which has a filter built in and
may be accurate enough, or replace both with a matched diode/filter pair
from someone like Thorlabs but that can be pricey!


On 9/4/2018 1:11 AM, Mark Kahrs wrote:
Yes indeed, it's the aforementioned TO-5.  What are your suggested
replacements?



On Mon, Sep 3, 2018 at 4:17 PM Adrian <Adrian@...> wrote:

As I say, the gain is set in the sensor head so it's in the feedback
loop of the main instrument, I have a 6501 photopic head but don't have
the 6511 (cosine corrected) version. I'll be surprised if there isn't a
cal pot under a sticker somewhere. An iffy pot will also cause what he
sees (I've had that) but if it is the diode then there are things out
there that will work.

    I've made a couple of slightly special (mechanically) heads which seem
to work fine using currently available diodes. He'll need to get a look
inside but most likely the diode is a TO5 wide bandwidth thing with a
separate filter to do the matching to the photopic curve with everything
behind a clever lens.

Adrian
On 9/3/2018 8:52 PM, Mark Kahrs wrote:
J6511.

He says it's the sensor and I believe him.  I suspect this may be made of
unobtanium.



On Mon, Sep 3, 2018 at 3:43 PM Adrian <Adrian@...> wrote:

There are a number of sensor heads available for this instrument, I have
several of them here. They come in both 'imperial' and 'metric' units.

In terms of electronic components they only have a photo diode, a pot
and a fixed resistor in them.

In terms of optical components it's mostly just a filter and baffles to
collimate the incoming light I think.

The pot and resistor set the gain in the main instrument thus the
calibration is done in the sensor head.

We need to know which head and which bit is toasted to help much
further!
Adrian


On 9/3/2018 8:23 PM, Mark Kahrs wrote:
A friend acquired a J16 but the sensor is, in his words, "toast".

Any thoughts on replacing such a beast?






5B10N with special blanking mode

Kurt Rosenfeld
 

This 5B10N has a special blanking mode: https://www.ebay.com/itm/232916392120

Anybody know anything about it?

Is this the Jon BATTERS of Grants Pass OR-A member of our group?

ROLYNN PRECHTL K7DFW
 

--- the forwarded message follows --


Is this the JON BATTERS of Grants Pass OR - a member of our group?


Rolynn
Tek Bvtn and Sunset 1966-1971

Jon BATTERS

ROLYNN PRECHTL K7DFW
 

Group,

The following was removed from my previous message. It is an email I just received from the Oregon State Police.


Rolynn
Tek Bvtn and Sunset 1966-1971


=================================================================================================


UPDATE VICTIM NAME RELEASED - HOMICIDE INVESTIGATION IN JOSEPHINE COUNTY

News Release from Oregon State Police
Posted on FlashAlert: September 4th, 2018 3:21 PM



The victim of the homicide has been identified as Jon Batters (70) of Grants Pass, OR.

Investigation is ongoing.

**********************************************************************************************************************************

On August 29, 2018 at approximately 5:25 PM deputies from the Josephine County Sheriff's Office responded to a call of deceased male at a residence on Riverbanks Rd. Upon arrival deputies located the body of an adult male at the residence. Josephine County requested a Major Crimes Team activation and the Oregon State Police was assigned to lead the investigation.

Investigation is continuing and no further information will be released at this time.

Sent via FlashAlert Newswire. Replies to this message do NOT go back to the sender.
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