Date   

Re: 7904 excessive shadow/flare

 

I enjoyed this discussion, being not so CRT educated as most people here.

I have a Non-Tek scope, the first one I have where the trace ghost is
actually noticeable enough to bother me.

I started looking for explanations and landed here where the most CRT
knowledgeable people are.

My CRO has 1.9 and 18kV acceleration voltages.

To add a little to the discussion on my oscilloscope in X-Y mode and spot
off centre, out of focus, with a little (optical) magnification the mesh
can be seen as a chess pattern on the wanted spot, the unwanted ghost spot
doesn't show it.

https://www.eevblog.com/forum/index.php?action=dlattach;topic=211046.0;attach=847330;image

https://www.eevblog.com/forum/index.php?action=dlattach;topic=211046.0;attach=847334;image

What is the mesh electrically connected to?



Le dimanche 7 juillet 2019, Ed Breya via Groups.Io <edbreya=
yahoo.com@groups.io> a écrit :

Haha - this tidbit of terminology just popped in from my unconscious
long-term storage. It was called "MSE" for "meshless scan expansion."
Googling the the full phrase quickly got a lot of hits, including this one:

https://patents.google.com/patent/US4137479A/en

Ed




Re: ebay 7104 arrived :-)

@0culus
 

Awesome! Incidentally, I'm also looking for actual manuals for my stuff, so if you find someone who has more than one copy would you drop me a note off list?

Sean


Re: National Instruments GPIB-400

toby@...
 

On 2019-10-03 11:13 a.m., Reginald Beardsley via Groups.Io wrote:
FYI I've decided to commission the design of an OSHW board to plug onto a $3 Arduino Nano with footprints for a BNC, USB B and either a 2x12 0.1" header or a PCB mount Centronics connector. The 2x12 header will allow easily making up custom GPIB cables using ribbon cable and IDC connectors. I made a 2 device adapter using an Uno. Soldering the ribbon cable to the Uno was quite a pain because of the way the cable mapped to the pins. Hence the 2x12 header.

The BNC is for a strobe signal for the 34401A and similar and the USB B to provide a more robust connector than the mini USB on the Nano.

A later version will use the Mega 256 with relays, T&H, RTC, etc.

My intent is to make OSSW/OSHW GPIB-USB-HS adapters available for <$10 without the need to find old GPIB cables.

The chap I'm having do the board is pretty busy with a couple of other projects, so it may be a while before the board design gets posted online.

The Nano will handle 10-12 GPIB devices as the 328P operates at 5V and can source or sink 40 mA per pin. At $3 + connectors for a GPIB-USB-HS adapter, the ATMEGA 328P deserves more respect than I had been giving it. They make great glue for old TTL interfaces. Most other MCUs won't drive TTL loads. Interestingly, the Nano is cheaper than a single IDC Centronics connector.
I also did a Nano-based GPIB project, but using driver ICs:
https://github.com/qu1j0t3/gpib-adapter


AR488 is an extension of the Prologix command set. ...
Reg




Re: Sanity check- is the TM500 interface spacing .150" or .156"?

Vince Vielhaber
 

Something to be careful about with the JAMMA extenders; they sometimes tie A & B sides together at the high number end, where the interconnect pins are. I had ICs popping their tops in an FC-501 because of it. Fortunately it was going to be parted out anyway, but I also remedied those pins that were tied together before anything else was plugged into it.

Vince.

On 10/03/2019 05:40 PM, Dennis Tillman W7PF wrote:
The JAMMA extenders have been around for a long time. I made one of them myself even though I already had a Tek TM500 extender. The big advantage of the JAMMA extender is its rock bottom price. It will do just fine assuming extenders are something that you use infrequently.

More recently Dan Meeks <dan-meeks@austin.rr.com> created a much more functional (and gorgeous) implementation of the TM500 flexible extender with several useful debugging features that make it more than just an extender. The price for the kit was also rock bottom: $22 + $7 shipping, and they were available through Amazon. Unfortunately they sold out. I bought one and I was very impressed. It quickly became my favorite extender.

You can still see the original Amazon listing to see what it looks like and read about what it can do at this link:
https://www.amazon.com/dp/B078SY3X1H

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Alexandre Souza
Sent: Thursday, October 03, 2019 2:26 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Sanity check- is the TM500 interface spacing .150" or .156"?

BTW
I did my extender with a JAMMA edge board female connector and a JAMMA edge board used to retrofit older boards (which before JAMMA standard, every single different game had a different pinout/connector) to JAMMA standard

Works well, I have it for decades =)




Re: ebay 7104 arrived :-)

Reginald Beardsley
 

Mel,

I've downloaded some of the PDFs, but not yet all. I have manuals for all my other gear. Many as PDF though I will probably get or print paper copies as that is much more convenient when working on the stuff.

What I *really* want is schematics and other component level repair data for the 11801. My understanding is that the museum has them, but the lawyers have not cleared them for release.

I'm collecting parts to allow me to measure bit skew for DSP pipelines on the Zynq and cyclone V FPGAs to create open source firmware for DSOs based on those chips. I've got four SD-26 heads so I just need to convert the differential 100 ohm high speed PMOD outputs on the Zybo Z7-20 to single ended 50 ohm. And find 8 cables which are close enough to the same lengths. I figure that my best shot is to buy 2 dozen SMA-M RG402 cables and pick the most closely matching pairs. Then use the delay adjustment for each head.

My goal is stackable math and filter pipelines a la LeCroy but with considerably more flexibility. Once I've written the FPGA code I'll start back to work on hijacking COTS DSOs from Siglent and GW Instek using the Zynq. I was making good progress on that until I accidentally fried the SPI flash chip while trying to sort out the factory programming header. I've not yet worked up the nerve to try to replace the chip. Hopefully I just fried that one cheap part and not the Zynq.

The motivation of this is the same as buying a 485 and a 7104. I do *not* like ringing on steps. As neither Keysight nor Rohde & Schwarz offer scopes which will do what I want even for $20K I decided to do it myself. Marketing wants to claim BW all the way to Nyquist and the unavoidable consequence is ringing on a step. For a decent edge you have to accept 50-70% of Nyquist as the -3dB corner.

I've never programmed an FPGA, but I spent my career in the oil industry doing DSP on general purpose computers. I did have a run in with an FPS-120B attached to an 11/780 once. So I'm familiar with the ugly side of DSP. And 20 years ago I wrote a parallel DSP code to run on an MPI cluster which required close to 2000 hours of work. I wrote *all* of it. So I do understand what I'm taking on.

Have Fun!
Reg


Re: Sanity check- is the TM500 interface spacing .150" or .156"?

 

The JAMMA extenders have been around for a long time. I made one of them myself even though I already had a Tek TM500 extender. The big advantage of the JAMMA extender is its rock bottom price. It will do just fine assuming extenders are something that you use infrequently.

More recently Dan Meeks <dan-meeks@austin.rr.com> created a much more functional (and gorgeous) implementation of the TM500 flexible extender with several useful debugging features that make it more than just an extender. The price for the kit was also rock bottom: $22 + $7 shipping, and they were available through Amazon. Unfortunately they sold out. I bought one and I was very impressed. It quickly became my favorite extender.

You can still see the original Amazon listing to see what it looks like and read about what it can do at this link:
https://www.amazon.com/dp/B078SY3X1H

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Alexandre Souza
Sent: Thursday, October 03, 2019 2:26 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Sanity check- is the TM500 interface spacing .150" or .156"?

BTW
I did my extender with a JAMMA edge board female connector and a JAMMA edge board used to retrofit older boards (which before JAMMA standard, every single different game had a different pinout/connector) to JAMMA standard

Works well, I have it for decades =)




--
Dennis Tillman W7PF
TekScopes Moderator


Re: Icom IC 720A

tekscopegroup@...
 

Best to first make sure if its actually the display controller chip is where the problem is located before looking at exotic solutions. IMO a one time design, development, debugging and building of an equivalent circuit would be a bit over optimistic of being realistically worth the effort and cost. Maybe if you are the owner of the radio and have enough uC knowledge, and the time and inclination to take that route. I like and appreciate older radios, vintage as they are called now a days by ebay sellers to try and make a killing, but we are not exactly here talking about a one of a kind high value very rare radio either, and worth putting a lot of time and resources into it. Then there is always the chance of a parts donor radio out there.


Re: Icom IC 720A

Alexandre Souza
 

Ah, IC720A, my first love <3

Em 03/10/2019 12:22, tekscopegroup@miwww.com escreveu:
Well I hope its not the display driver chip, as helpful as Icom America parts department always is, of course there is probably minus one chance they would have this part available. Best bet would be a donor radio, or board as you mentioned, even only for a temporary comparison swap. This next idea might be a
In cheap microcontroller days, I see no why the entire frequency counter module cannot be exchanged for a small board with a microcontroller. And VFD driving isn't exactely rocket science.

--
---8<---Corte Aqui---8<---
https://www.tabalabs.com.br
https://tabajara-labs.blogspot.com


Re: Icom IC 720A

tekscopegroup@...
 

On Wed, Oct 2, 2019 at 12:25 PM, John Stoole wrote:
Thanks Alex for the prompt reply...all the display voltages appear to be fine,
and I do notice as I power OFF the display flashes all it digit's with " 8 "
but as soon as I power ON nothing just a blank screen, I am not expert when it
comes to all these digital circuits, more at hone with the old tubes !!!!
Well I hope its not the display driver chip, as helpful as Icom America parts department always is, of course there is probably minus one chance they would have this part available. Best bet would be a donor radio, or board as you mentioned, even only for a temporary comparison swap. This next idea might be a long shot, specially given that you mentioned that the radio is receiving and transmitting fine, but it might be possible there is some kind of display enable line that shuts down the display if for example a PLL unlock condition is sensed to let the operator know and presumably to prevent operation on random frequencies. Have you verified that the radio is actually on a valid frequency and it is rock solid stable? An unlocked PLL can sometimes still allow the radio to appear to be working specially without a working display where one does not know on what frequency the radio is actually set. That enable line, if it exists at all, is what I would look for next.

Alex


Re: National Instruments GPIB-400

Reginald Beardsley
 

FYI I've decided to commission the design of an OSHW board to plug onto a $3 Arduino Nano with footprints for a BNC, USB B and either a 2x12 0.1" header or a PCB mount Centronics connector. The 2x12 header will allow easily making up custom GPIB cables using ribbon cable and IDC connectors. I made a 2 device adapter using an Uno. Soldering the ribbon cable to the Uno was quite a pain because of the way the cable mapped to the pins. Hence the 2x12 header.

The BNC is for a strobe signal for the 34401A and similar and the USB B to provide a more robust connector than the mini USB on the Nano.

A later version will use the Mega 256 with relays, T&H, RTC, etc.

My intent is to make OSSW/OSHW GPIB-USB-HS adapters available for <$10 without the need to find old GPIB cables.

The chap I'm having do the board is pretty busy with a couple of other projects, so it may be a while before the board design gets posted online.

The Nano will handle 10-12 GPIB devices as the 328P operates at 5V and can source or sink 40 mA per pin. At $3 + connectors for a GPIB-USB-HS adapter, the ATMEGA 328P deserves more respect than I had been giving it. They make great glue for old TTL interfaces. Most other MCUs won't drive TTL loads. Interestingly, the Nano is cheaper than a single IDC Centronics connector.

AR488 is an extension of the Prologix command set. I want to automate a full cal of my test bench via a pair of Radial ST6P SMA relays and a patch panel with N, BNC & banana connectors so I'm adding support to AR488 for that and will be using a Pi or Beagle for LAN connectivity and archival storage of cal results to an SD card. I also want to run some long term studies of voltage reference aging and hysteresis which is the motivation for adding T&H, RTC and read strobe commands.

Have Fun!
Reg


Looking for 7104 crt , trade

oliver johnson
 

I have a 7103 rack mount scope , my crt is bad and would like to replace it with a good working crt . I would like to trade someone that has crts and may want one that i have , i have some 5 series 4 series 7 series and other tek crt , in addition to that i have some hp and leader crt , if you are looking for something specific let me know and maybe we can help each other .


Re: TDS upgrades

Vintage Test
 

Thanks Håkan,

It’s really useful to have the service manuals for all of the ‘you can’t repair this, so just send it back to Tek, remortgage your house, sell your car and get the wife a part-time job and we’ll sort it for you’ type of kit!

Cheers,
Mel
you can never have enough oscilloscopes, DMMs, valve testers or soldering irons . . .


Re: ebay 7104 arrived :-)

Vintage Test
 

Hi Reg,

Nice acquisition! I have just about every manual for most popular test gear, but all in pdf format. Any good to you?

Cheers,
Mel

--
you can never have enough oscilloscopes, DMMs, valve testers or soldering irons . . .


Re: National Instruments GPIB-400

Arie de Muijnck
 

I have ordered one. Should arrive in a few weeks.
I checked the chip's datasheet - more powerful than the ATMEL:
https://www.silabs.com/products/mcu/8-bit/c8051f38x/device.c8051f383-gq
It should drive more than a few instruments.
I'll try to remember to post an update.

Arie


Re: Sanity check- is the TM500 interface spacing .150" or .156"?

Alexandre Souza
 

BTW
I did my extender with a JAMMA edge board female connector and a JAMMA edge
board used to retrofit older boards (which before JAMMA standard, every
single different game had a different pinout/connector) to JAMMA standard

Works well, I have it for decades =)

---8<---Corte aqui---8<---
http://www.tabajara-labs.blogspot.com
http://www.tabalabs.com.br
---8<---Corte aqui---8<---


Em qui, 3 de out de 2019 às 06:01, Albert Otten <aodiversen@concepts.nl>
escreveu:

On Thu, Oct 3, 2019 at 01:55 AM, EJP wrote:


It is JAMMA, but they only make the card. The extender is a kit vended by
someone else.

https://web.archive.org/web/20120520114225/http://www.jammaboards.com/store/tektronix-tm500-series-extender-kit-tm500-kit.html

Albert
Albert




Re: National Instruments GPIB-400

David Slipper
 

Sorry I meant that the Aliexpress version is tempting.

>> I built one of
these<http://egirland.blogspot.com/2014/03/arduino-uno-as-usb-to-gpib-controller.html>;
based on an UNO in my junk box - it works fine >> but can only drive 2
or 3 instruments.

It's also "free" :-)

The AR488 version is tempting though.

David


On 02/10/2019 22:12, Arie de Muijnck wrote:

Thanks for that AR488 info, that looks really good.
I was searching for a low cost USB-GPIB adapter.

BTW, did anyone ever buy this (looks new on aliexpress),
it's a compact open source Prologic compatible for about $20:
https://www.aliexpress.com/item/4000034884174.html
The open source is here:
https://github.com/fenrir-naru/gpib-usbcdc

Regards,
Arie de Muijnck



.





Re: Sanity check- is the TM500 interface spacing .150" or .156"?

Albert Otten
 

On Thu, Oct 3, 2019 at 01:55 AM, EJP wrote:


It is JAMMA, but they only make the card. The extender is a kit vended by
someone else.
https://web.archive.org/web/20120520114225/http://www.jammaboards.com/store/tektronix-tm500-series-extender-kit-tm500-kit.html

Albert
Albert


Re: National Instruments GPIB-400

David Slipper
 

I built one of these<http://egirland.blogspot.com/2014/03/arduino-uno-as-usb-to-gpib-controller.html>; based on an UNO in my junk box - it works fine but can only drive 2 or 3 instruments.

It's also "free" :-)

The AR488 version is tempting though.

David

On 02/10/2019 22:12, Arie de Muijnck wrote:

Thanks for that AR488 info, that looks really good.
I was searching for a low cost USB-GPIB adapter.

BTW, did anyone ever buy this (looks new on aliexpress),
it's a compact open source Prologic compatible for about $20:
https://www.aliexpress.com/item/4000034884174.html
The open source is here:
https://github.com/fenrir-naru/gpib-usbcdc

Regards,
Arie de Muijnck



.


Re: National Instruments GPIB-400

Arie de Muijnck
 

On 2019-10-01 23:12, Reginald Beardsley via Groups.Io wrote:


FWIW There is an entire EEVblog thread on the AR488 FW which is based on
an Arduino Uno, but expanding to support the Mega 256, STM32F103, and
others. Now that the author has completed a major update on the FW to
simplify customization I'm going to add a number of features to control
external relays, read a temperature and humidity sensor, real time clock
and feed a strobe signal to synchronize measurements with the 34401As.
Thanks for that AR488 info, that looks really good.
I was searching for a low cost USB-GPIB adapter.

BTW, did anyone ever buy this (looks new on aliexpress),
it's a compact open source Prologic compatible for about $20:
https://www.aliexpress.com/item/4000034884174.html
The open source is here:
https://github.com/fenrir-naru/gpib-usbcdc

( https://github.com/fenrir-naru/gpib-usbcdc )

Regards,
Arie de Muijnck



Re: National Instruments GPIB-400

Arie de Muijnck
 

On 2019-10-01 23:12, Reginald Beardsley via Groups.Io wrote:


FWIW There is an entire EEVblog thread on the AR488 FW which is based on
an Arduino Uno, but expanding to support the Mega 256, STM32F103, and
others. Now that the author has completed a major update on the FW to
simplify customization I'm going to add a number of features to control
external relays, read a temperature and humidity sensor, real time clock
and feed a strobe signal to synchronize measurements with the 34401As.
Thanks for that AR488 link, I'm also looking for an affordable USB-GPIB adapter.

BTW: did anyone use this? It seems new on AliExpress, a EUR 18 clone from an opensource project:
https://www.aliexpress.com/item/4000034884174.html
( https://www.aliexpress.com/item/4000034884174.html ) https://github.com/fenrir-naru/gpib-usbcdc

Regards,
Arie

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