Topics

"liquid crystal driver" sighting

p mc
 

This "lot of 3" item on eBay includes a couple of 5A1xN scope plugins and a "liquid crystal driver" plugin:

https://www.ebay.com/itm/LOT-OF-3-TEKTRONIX-PLUG-IN-5A18N-DUAL-TRACE-AMP-5A15N-AMP-LIQUID-CRYSTAL-DRIVER/312803078179

The only mentions of a "liquid crystal driver" plugin that I've found are in Dennis T's list of TM500/TM5000 plugins at davmar.org & TekWiki.

The eBay listing has crude front & back pictures. I might get around to adding the pix to TekWiki. Feel free to beat me to it.

Just for curiosity, does anyone here know anything about this mysterious object?

Craig Sawyers <c.sawyers@...>
 

At $22 BIN I'm surprised no one in the US has taken a punt just to find out what that plugin does!

The thing that puts me off doing precisely that is $104 shipping to the UK!!!

Craig

This "lot of 3" item on eBay includes a couple of 5A1xN scope plugins and a "liquid crystal driver"
plugin:

https://www.ebay.com/itm/LOT-OF-3-TEKTRONIX-PLUG-IN-5A18N-DUAL-TRACE-AMP-5A15N-AMP-
LIQUID-CRYSTAL-DRIVER/312803078179

The only mentions of a "liquid crystal driver" plugin that I've found are in Dennis T's list of
TM500/TM5000 plugins at davmar.org & TekWiki.

The eBay listing has crude front & back pictures. I might get around to adding the pix to TekWiki.
Feel
free to beat me to it.

Just for curiosity, does anyone here know anything about this mysterious object?

Vince Vielhaber
 

It's $56 shipping across the US or I would've.

Vince.

On 10/15/2019 07:29 PM, Craig Sawyers wrote:
At $22 BIN I'm surprised no one in the US has taken a punt just to find out what that plugin does!

The thing that puts me off doing precisely that is $104 shipping to the UK!!!

Craig

This "lot of 3" item on eBay includes a couple of 5A1xN scope plugins and a "liquid crystal driver"
plugin:

https://www.ebay.com/itm/LOT-OF-3-TEKTRONIX-PLUG-IN-5A18N-DUAL-TRACE-AMP-5A15N-AMP-
LIQUID-CRYSTAL-DRIVER/312803078179

The only mentions of a "liquid crystal driver" plugin that I've found are in Dennis T's list of
TM500/TM5000 plugins at davmar.org & TekWiki.

The eBay listing has crude front & back pictures. I might get around to adding the pix to TekWiki.
Feel
free to beat me to it.

Just for curiosity, does anyone here know anything about this mysterious object?


p mc
 

Yeah, that.

But someone snagged it. Someone willing to pay for delivery by angel choir so I doubt they just wanted the 5A1xN plugins.

Someone here, perchance? TekWiki would like to hear from you...

Glenn Little
 

I bought it.
I got the postage down to $15.00.
When it gets here I will get some better pictures, inside and out.

Glenn

On 10/17/2019 9:48 PM, p mc wrote:
Yeah, that.

But someone snagged it. Someone willing to pay for delivery by angel choir so I doubt they just wanted the 5A1xN plugins.

Someone here, perchance? TekWiki would like to hear from you...


--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

Glenn Little
 

I bought it.
I got the postage down to $15.00.
When it gets here I will get some better pictures, inside and out.

Glenn

On 10/17/2019 9:48 PM, p mc wrote:
Yeah, that.

But someone snagged it. Someone willing to pay for delivery by angel choir so I doubt they just wanted the 5A1xN plugins.

Someone here, perchance? TekWiki would like to hear from you...


--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

Mlynch001
 

We will all be waiting To hear all about this little item.

--
Michael Lynch
Dardanelle, AR

p mc
 

...or someone who got the postage down to reasonable.

Bravo, sir.

Glenn Little
 

I will soon have pictures. How do I get these on TekWiki?

Glenn

On 10/17/2019 9:48 PM, p mc wrote:
Yeah, that.

But someone snagged it. Someone willing to pay for delivery by angel choir so I doubt they just wanted the 5A1xN plugins.

Someone here, perchance?
TekWiki would like to hear from you...


--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

Dave Daniel
 

Glenn,

I believe that there are quite a few people who can upload the photos and update or create the TekWiki page. I can do so if you wish. Just send the photos and any descriptive information you have.

DaveD

Sent from a small flat thingy

On Oct 31, 2019, at 14:32, Glenn Little <glennmaillist@...> wrote:

I will soon have pictures. How do I get these on TekWiki?

Glenn


On 10/17/2019 9:48 PM, p mc wrote:
Yeah, that.

But someone snagged it. Someone willing to pay for delivery by angel choir so I doubt they just wanted the 5A1xN plugins.

Someone here, perchance?
TekWiki would like to hear from you...


--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"



Magic_Smoke
 

https://www.davmar.org/TE/Tillman/TM500-Tillman.html lists it as "Unknown manucturer." Who knew this topic would be so exciting? I'm on the edge of my seat!

p mc
 

(seeing this a few weeks later)

Glenn,

Like DaveD says, lots of people here can help with TekWiki. Or you can ask kurt.harlem@... for a TekWiki account if you want to get into that yourself.

Back in October I made a stub page with crops from the pictures from the eBay listing:
http://w140.com/tekwiki/wiki/Liquid_Crystal_Driver

A first question might be what type of mainframe the plugin plugs into. If you haven't already sussed that, a picture of the edge connector cut-outs will help.

Curious to see what you've got...

keantoken
 

Liquid crystals are used in welding masks to darken the weld flash instantly. I think they have other applications in high speed photography, and electronic shutters. So maybe this was part of some kind of optics laboratory?

In the original Ebay picture it was possible to read the text on the plugin. On the wiki page the test is unreadable. Here is the full size image with readable text.

https://www.ebay.com/itm/LOT-OF-3-TEKTRONIX-PLUG-IN-5A18N-DUAL-TRACE-AMP-5A15N-AMP-LIQUID-CRYSTAL-DRIVER-/312803078179?nma=true&si=0Rv3bZb%252FLMGiec3%252F7Qc8K%252F3QYFs%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

p mc
 

I've updated TekWiki with the better images. Clearing browser cache & reloading the page may be required to see them.

Strange sidebar re the images: In October I thought there were better images but when I went to collect the images to crop , it seemed not so. Now prompted by keantoken to look again I see that on my phone the lo res image in the listing "expands" into the same lo res image on a cleaner background. So I chalked up the memory of better resolution to false/suggested memory, since "liquid crystal driver" appears in the description, and went ahead with the poorer images. This time, before the listing goes away, I went back with a desktop browser to get the better images with semi-legible front panel text.

The better picture almost shows the connector key slots. But not convincingly. So I'll not bias anyone else's speculation with my speculation.

Hopefully better images & info from Mr. Little will replace all that anyhow.

Glenn Little
 

I will try and get hi res pix posted this weekend.
Hope to have schematic drawn early next year.
This appears to fit a TM-500 series frame.
The unit appears to have two channels.
The main board id very good quality.
There are two "proto" type boards in the unit.
One is for fuses.
The other has a pair of 74121 ics on it.
When I got it the edge card connector was damaged, thankfully if a place where there are no used pins.
There was one power transistor missing and I can replace it with one like in the other channel.
There is also a ground binding post missing, this is easily replaced.
The pictures will be of the unit as I received it.
This has controls for PW UPPER and PW LOWER for both channels.
There is also a DELAY and AMPLITUDE control for each channel.
There is a BNC for the top channel only INPUT.
There is a BNC for SYNC.
The SYNC appears to go to both channels.
There is a label on the front REL 11, so, maybe there are others out there.
The front binding posts are UPPER OUTPUT, LOWER OUTPUT and GROUND for each channel.
The active backplane pins are 2A, 3A, 6A, 7A, 8A, 9A, 10A, 12A, and 7B.
8B, 11B and 8A are connected.
12A and 12B are connected together.
All of these pins are power related, so the only inputs and outputs are via the front panel.
There is a keyway between pins 6 and 7.
There are "flying" jumpers between some IC pins with some of these pins lifted from the sockets.
Probably still a work in progress.
The front panel is thin aluminum with, what looks like, photo etching for the labeling and shading.
Harmonica connectors are used to connect to the board.

More to follow
Glenn

On 12/10/2019 12:50 PM, p mc wrote:
(seeing this a few weeks later)

Glenn,

Like DaveD says, lots of people here can help with TekWiki. Or you can ask kurt.harlem@... for a TekWiki account if you want to get into that yourself.

Back in October I made a stub page with crops from the pictures from the eBay listing:
http://w140.com/tekwiki/wiki/Liquid_Crystal_Driver

A first question might be what type of mainframe the plugin plugs into. If you haven't already sussed that, a picture of the edge connector cut-outs will help.

Curious to see what you've got...





--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

p mc
 

Sounds like it has fallen into good hands!

Ed Breya
 

Don't be surprised if this turns out to be Tek-made - you may be able to tell by the boards, parts, and construction techniques. Tek did work with LCDs in the late 1980s to early 1990s. The well known ones are the color-shutter, used with CRTs in various products, and the plasma-addressed liquid crystal (PALC) technology. So, it's possible that this setup was used for in-house R&D.

The color-shutter is what gives many of the TDS scopes their multi-color display capability. For those who never heard of PALC, here's a very succinct description:
https://en.wikipedia.org/wiki/Plasmatron

Ed

Glenn Little
 

On 12/10/2019 10:28 PM, Glenn Little WB4UIV wrote:
I will try and get hi res pix posted this weekend.
Hope to have schematic drawn early next year.
This appears to fit a TM-500 series frame.
The unit appears to have two channels.
The main board id very good quality.
There are two "proto" type boards in the unit.
One is for fuses.
The other has a pair of 74121 ics on it.
When I got it the edge card connector was damaged, thankfully if a place where there are no used pins.
There was one power transistor missing and I can replace it with one like in the other channel.
There is also a ground binding post missing, this is easily replaced.
The pictures will be of the unit as I received it.
This has controls for PW UPPER and PW LOWER for both channels.
There is also a DELAY and AMPLITUDE control for each channel.
There is a BNC for the top channel only INPUT.
There is a BNC for SYNC.
The SYNC appears to go to both channels.
There is a label on the front REL 11, so, maybe there are others out there.
The front binding posts are UPPER OUTPUT, LOWER OUTPUT and GROUND for each channel.
The active backplane pins are 2A, 3A, 6A, 7A, 8A, 9A, 10A, 12A, and 7B.
8B, 11B and 8A are connected.
12A and 12B are connected together.
All of these pins are power related, so the only inputs and outputs are via the front panel.
There is a keyway between pins 6 and 7.
There are "flying" jumpers between some IC pins with some of these pins lifted from the sockets.
Probably still a work in progress.
The front panel is thin aluminum with, what looks like, photo etching for the labeling and shading.
Harmonica connectors are used to connect to the board.

More to follow
Glenn



On 12/10/2019 12:50 PM, p mc wrote:
(seeing this a few weeks later)

Glenn,

Like DaveD says, lots of people here can help with TekWiki. Or you can ask  kurt.harlem@... for a TekWiki account if you want to get into that yourself.

Back in October I made a stub page with  crops from the pictures from the eBay listing:
http://w140.com/tekwiki/wiki/Liquid_Crystal_Driver

A first question might be what type of mainframe the plugin plugs into. If you haven't already sussed that, a picture of the edge connector cut-outs will help.

Curious to see what you've got...





--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"

p mc
 

Thank you, Mr. Little, for starting to fill in a blank spot on the map.

At TekWiki I cleaned out the obsolete stub text and poor front panel image.

Glenn Little
 

I am currently working on drawing a schematic. Slow going. Hope to have it done and posted sometime in February.

Glenn

On 1/17/2020 3:04 AM, p mc wrote:
Thank you, Mr. Little, for starting to fill in a blank spot on the map.

At TekWiki I cleaned out the obsolete stub text and poor front panel image.


--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"