EEVblog Electronics Community Forum

EEVblog => EEVblog Specific => Topic started by: EEVblog on December 02, 2013, 01:31:07 pm

Title: EEVblog #553 - Mailbag
Post by: EEVblog on December 02, 2013, 01:31:07 pm
DIN 41612 Roth Electronics Extender Card: http://docs-asia.electrocomponents.com/webdocs/068f/0900766b8068f80e.pdf (http://docs-asia.electrocomponents.com/webdocs/068f/0900766b8068f80e.pdf)
Lichtenberg Figure: http://en.wikipedia.org/wiki/Lichtenberg_figure (http://en.wikipedia.org/wiki/Lichtenberg_figure)
http://focusdesigns.com/ (http://focusdesigns.com/) Self Balancing Unicycle
Tektronix 213 oscilloscope: http://www.teknetelectronics.com/DataSheet/TEKTRONIX/TEKTR_21325410.pdf (http://www.teknetelectronics.com/DataSheet/TEKTRONIX/TEKTR_21325410.pdf)
http://www.testequipmentconnection.com/specs/Tektronix_213.PDF (http://www.testequipmentconnection.com/specs/Tektronix_213.PDF)

EEVblog #553 - Mailbag (https://www.youtube.com/watch?v=gRiadnjyBdo#ws)
Title: Re: EEVblog #553 - Mailbag
Post by: c4757p on December 02, 2013, 01:41:14 pm
I'm probably just too much of a Tek fanboy, but damn, I want that cute little scope!
Title: Re: EEVblog #553 - Mailbag
Post by: dr.diesel on December 02, 2013, 01:45:22 pm
Yeah, I have a raging erection, that Tek is awesome.
Title: Re: EEVblog #553 - Mailbag
Post by: ludzinc on December 02, 2013, 02:41:03 pm
A good read on Litchenberg figures can be found here:

http://www.howtospotapsychopath.com/2007/12/03/lichtenbergia/ (http://www.howtospotapsychopath.com/2007/12/03/lichtenbergia/)

And some videos of them being made - also explains why the figure is captured in a layer.

Making "Captured Lightning" (Mllion-volt Sculptures) (https://www.youtube.com/watch?v=9Po35g23fYI#)

Title: Re: EEVblog #553 - Mailbag
Post by: andtfoot on December 02, 2013, 02:53:17 pm
Oooohh... do want one of those Lichtenberg thingies...  :P

Edit: Which Mike kindly pointed out in this thread (https://www.eevblog.com/forum/blog/553-lichtenberg-figures/) that you can get from here (http://www.capturedlightning.com/).
Title: Re: EEVblog #553 - Mailbag
Post by: Bored@Work on December 02, 2013, 07:40:37 pm
Dave, a quick google on the Tek 213 revealed those can have some battery pack inside that used to leak. Maybe a quick check on yours is in order to limit any potential damage.
Title: Re: EEVblog #553 - Mailbag
Post by: N2IXK on December 02, 2013, 07:56:15 pm
According to the TekWiki, the 213 portable scope was first introduced in 1975.

http://w140.com/tekwiki/wiki/213 (http://w140.com/tekwiki/wiki/213)

Not a lot of people had digital multimeters back then, so this scope must have been a real piece of geek porn in its day...
Title: Re: EEVblog #553 - Mailbag
Post by: Nilres on December 02, 2013, 08:28:43 pm
Isn't it still geek porn? :) I love it!
Title: Re: EEVblog #553 - Mailbag
Post by: edpalmer42 on December 02, 2013, 09:01:23 pm
I used to work for a telco.  We had one of the Tek miniscopes in our testroom.  I think it was Model 214 - dual trace storage, 500 KHz bandwidth.  Very cute!

Here's some info on the family:  http://w140.com/tekwiki/wiki/Main_Page#200_Series (http://w140.com/tekwiki/wiki/Main_Page#200_Series)

Ed
Title: Re: EEVblog #553 - Mailbag
Post by: Jon86 on December 02, 2013, 09:05:52 pm
That joke about the queen made me laugh more than I should have  :-DD
Title: Re: EEVblog #553 - Mailbag
Post by: joaoc on December 02, 2013, 09:12:24 pm
This video shows how to do some pattern (in the end)

The production of Lichtenberg figure sculptures (Shockfossils) (https://www.youtube.com/watch?v=8biE3uP_nOI#)
Title: Re: EEVblog #553 - Mailbag
Post by: dewhite2485 on December 02, 2013, 10:59:41 pm
This is Derek the one who sent you the scope, Im glad you liked it so much! When I got it on ebay the seller had it advertised as untested/non working, lucky for me when I got it everything worked like a charm. Some one has modified it slightly, the BNC connector on the back is not original to the design but seems to work. It didnt have the internal battery when I got it, but should be easy enough to replace if you wanted to use it cordless. Ive had the covers off it before so I know what it looks like inside, but it will be interesting to get a more technical look into its construction and operation.
Title: Re: EEVblog #553 - Mailbag
Post by: EEVblog on December 02, 2013, 11:21:59 pm
This is Derek the one who sent you the scope

Thanks Derek, I think this teardown will be popular!  :-+
Title: Why we like Mailbags ? Because it is like a little Christmas (no text)
Post by: Chipguy on December 02, 2013, 11:23:15 pm
Told ya, no text :)
Title: Re: EEVblog #553 - Mailbag
Post by: dr.diesel on December 02, 2013, 11:28:40 pm
Thanks Derek, I think this teardown will be popular!  :-+

Tomorrow is Tuesday     ;D
Title: Re: EEVblog #553 - Mailbag
Post by: synapsis on December 03, 2013, 12:10:29 am
That scope is awesome! It's the numerical readout that made me want one. Nixie tubes are *so* last year. (Decade?)
Title: Re: EEVblog #553 - Mailbag
Post by: N2IXK on December 03, 2013, 01:52:24 am
Would really like Dave to tear into the character generator circuitry. I assume it is some kind of vector system, not raster scanned.  I agree that the CRT readout has it all over Nixies for sheer coolness. You can get CRT clocks as a kit nowadays:

http://oscilloclock.com/ (http://oscilloclock.com/)
http://www.cathodecorner.com/sc200c.html (http://www.cathodecorner.com/sc200c.html)

For anyone who is curious about the guts of the Tek 213 and can't wait for Dave's teardown, check this out:

Tektronix 213 DMM Repair Progress (https://www.youtube.com/watch?v=fPmQ9Ce4TL0#)
Title: Re: EEVblog #553 - Mailbag
Post by: Len on December 03, 2013, 02:37:05 am
Would really like Dave to tear into the character generator circuitry. I assume it is some kind of vector system, not raster scanned.

The char gen is a single chip with 4-bit binary input and x, y, z vector output.

Schematics for the Tektronix 213 are here: http://w140.com/tekwiki/wiki/213 (http://w140.com/tekwiki/wiki/213)
Title: Re: EEVblog #553 - Mailbag
Post by: fpliuzzi on December 03, 2013, 03:10:24 am
Dave,
If you're interested in some info about that unusual CRT contained in the Sinclair portable flat TV, the "AndyDaviesByTheSea" channel on youtube has a video where the gentleman describes the part he played in the development of that CRT.

The video is "I little bit about my work and Sinclair's flat TV".  The Sinclair part starts at the 6:18 point.

Regards
Title: Re: EEVblog #553 - Mailbag
Post by: Zad on December 03, 2013, 04:37:29 am
Rick Dickinson, the fella who did the industrial design, has some photos of his work on the Sinclair TV on his Flickr page:

(http://farm2.staticflickr.com/1355/1221226301_6720344d63.jpg)

http://www.flickr.com/photos/9574086@N02/sets/72157601627816164/ (http://www.flickr.com/photos/9574086@N02/sets/72157601627816164/)


I got a faulty one from a ham radio rally in the early 1990s and played around with it. The innards are pretty simple, with almost all the work done on one chip. The real interest is in the CRT design, as I'm sure people will see!

Title: Re: EEVblog #553 - Mailbag
Post by: rr100 on December 03, 2013, 05:52:58 am
Yeah, I have a raging erection, that Tek is awesome.

If it was any longer I would've pissed myself. Awesome stuff!
1975 ... and true RMS to boot.
BRB, nature calls :-)
Title: Re: EEVblog #553 - Mailbag
Post by: amyk on December 03, 2013, 12:05:08 pm
Would really like Dave to tear into the character generator circuitry. I assume it is some kind of vector system, not raster scanned.  I agree that the CRT readout has it all over Nixies for sheer coolness. You can get CRT clocks as a kit nowadays:

http://oscilloclock.com/ (http://oscilloclock.com/)
http://www.cathodecorner.com/sc200c.html (http://www.cathodecorner.com/sc200c.html)
This reminded me of an article I read quite some time ago about using completely analog means to generate characters for a vector CRT, if I remember correctly it was a PDF scan of something from the 50s-60s era. Anyone know what I'm talking about?
Title: Re: EEVblog #553 - Mailbag
Post by: tjw on December 03, 2013, 12:17:38 pm
Hi,
    GK mentioned this in his home brew analog computer thread, specifically :

 https://www.eevblog.com/forum/projects/home-brew-analog-computer-system/165/ (https://www.eevblog.com/forum/projects/home-brew-analog-computer-system/165/)

GK links to http://www.nixiebunny.com/crtgen/crtgen.html (http://www.nixiebunny.com/crtgen/crtgen.html) about half way down page 12 of the thread.

Regards, TJW.
Title: Re: EEVblog #553 - Mailbag
Post by: 84GKSIG on December 03, 2013, 12:53:47 pm
that little scope is just beautiful! i need one just like it! now!
Title: Re: EEVblog #553 - Mailbag
Post by: Balaur on December 03, 2013, 03:10:56 pm
I hope Dave got some footage of the Sinclair TV working before the Analogue signal was switched off. Damned close call if he did, or didn't.

IIRC, the TV wasn't working, as the main IC was missing (as described in the message accompanying the TV).
Title: Re: EEVblog #553 - Mailbag
Post by: Stonent on December 03, 2013, 08:55:47 pm
Yeah, I have a raging erection, that Tek is awesome.

If it was any longer I would've pissed myself. Awesome stuff!
1975 ... and true RMS to boot.
BRB, nature calls :-)

If symptoms appear for more than 4 hours call your doctor.  I never understood those warnings. There's a lot less embarrassing ways to fix the problem than calling the doctor.
Title: Re: EEVblog #553 - Mailbag
Post by: Scott on December 03, 2013, 11:18:34 pm
I've got four of the 200 series Tek scopes (214, 221 storage, and two 213 DMMs). I'll give away my secret: buy the ones on eBay that are not working at all. Usually the only thing wrong is the NiCd battery pack. If the battery pack is shot, the units often wont even run on AC power. Also, don't power the unit from AC power unless an battery pack is installed.

They are great little scopes. I was able to fit three scopes in my carry on luggage for Maker Faire last year!
Title: Re: EEVblog #553 - Mailbag
Post by: synapsis on December 03, 2013, 11:31:31 pm
But now that Dave's had one on his channel, the price of the scopes will go through the roof!
Title: Re: EEVblog #553 - Mailbag
Post by: Stonent on December 04, 2013, 03:34:41 am
But now that Dave's had one on his channel, the price of the scopes will go through the roof!

Bonus if someone can figure out how to build a small scope board that connects to the back of a Sinclair TV!
Title: Re: EEVblog #553 - Mailbag
Post by: Zad on December 04, 2013, 03:48:52 am
You could probably run a (functional) Sinclair TV quite easily off the Raspberry Pi composite video output. Someone has to try that!
Title: Re: EEVblog #553 - Mailbag
Post by: amyk on December 04, 2013, 06:31:48 am
Hi,
    GK mentioned this in his home brew analog computer thread, specifically :

 https://www.eevblog.com/forum/projects/home-brew-analog-computer-system/165/ (https://www.eevblog.com/forum/projects/home-brew-analog-computer-system/165/)

GK links to http://www.nixiebunny.com/crtgen/crtgen.html (http://www.nixiebunny.com/crtgen/crtgen.html) about half way down page 12 of the thread.

Regards, TJW.
That's the one! :-+

I was able to easily find the PDF version after seeing that: http://www.thecorememory.com/GenCharforCRR.pdf (http://www.thecorememory.com/GenCharforCRR.pdf)
Title: Re: EEVblog #553 - Mailbag
Post by: Stonent on December 04, 2013, 07:21:36 am
You could probably run a (functional) Sinclair TV quite easily off the Raspberry Pi composite video output. Someone has to try that!

You'd need an RF Modulator to convert the Comp to RF signals.
Title: Re: EEVblog #553 - Mailbag
Post by: Zad on December 05, 2013, 03:29:39 am
It depends on what goes on inside the chip. It has a composite video output pin that you should be able to tap onto to inject the Rasp Pi's analogue output. It may be that the chip samples the signal before this point to derive synch etc.
Title: Re: EEVblog #553 - Mailbag
Post by: N2IXK on December 05, 2013, 03:50:21 am
There is a block diagram of the ZN401E-2 chip here:

http://www.thevalvepage.com/tv/sinclair/ftv1/announc.htm (http://www.thevalvepage.com/tv/sinclair/ftv1/announc.htm)

Looks like the composite video could be injected right at the detector output, feeding both the CRT drive and the sync separator.

Does anyone have a copy of the actual Ferranti datasheet for the chip, or was this a proprietary design just for Sinclair? A really interesting design, using what appears to be a synchronous detector for the audio, and a PLL with dual DACs to produce the deflection waveforms.
Title: Re: EEVblog #553 - Mailbag
Post by: EEVblog on December 05, 2013, 04:09:24 am
There is a block diagram of the ZN401E-2 chip here:
http://www.thevalvepage.com/tv/sinclair/ftv1/announc.htm (http://www.thevalvepage.com/tv/sinclair/ftv1/announc.htm)
Looks like the composite video could be injected right at the detector output, feeding both the CRT drive and the sync separator.

The chip is needed to generate all the timing though. Could be done manually, but messy.
Title: Re: EEVblog #553 - Mailbag
Post by: N2IXK on December 05, 2013, 04:20:15 am
Yes, without the magic chip, getting anything on the screen would be a LOT of work. Almost the entire signal processing system (video, audio, sync, and sweep generation) is contained in that little guy...
Title: Re: EEVblog #553 - Mailbag
Post by: JoannaK on December 05, 2013, 04:36:55 am
Sounds a lot like Fpga.project.. or Propeller.
Title: Re: EEVblog #553 - Mailbag
Post by: amyk on December 05, 2013, 06:40:08 am
I remember seeing online a schematic + datasheet for a Chinese-made portable CRT TV (recently) that had everything on one chip... but can't find it now. :(

Edit: found it!
http://shiximm.com/baogaofanwen/261729.html (http://shiximm.com/baogaofanwen/261729.html)
http://datasheet.seekic.com/PdfFile/D29/D2915.pdf (http://datasheet.seekic.com/PdfFile/D29/D2915.pdf)
Title: Re: EEVblog #553 - Mailbag
Post by: SeanB on December 05, 2013, 07:25:30 pm
n the late 1980's Maplin was selling off the boards as spare parts, possibly working but without the CRT, main chip and tuner. Probably ones that were DOA from the assembly line, where they would pull the most expensive items ( Tuner, CRT and the ASIC) from them to reuse. Probably the main reason the ASIC was in a socket is that they were heat sensitive, and were the single highest cost item in the set, probably costing more than the CRT.

I watched the Andie Davies memories about Sinclair, was very entertaining on how difficult those were to make.

As to the battery packs, they were a part of instant film packs, used to drive the camera motors, focussing system and the flash circuitry. Pretty impressive for the first mass produced pouch cells, they were nice to use in projects as discards from camera packs, still having a lot of power left in them after the 120 shots from the film unit. Only issue was connecting to the aluminium foil tabs as they were not solderable. I generally used a crocodile clip or paper clip as a contact with a piece of magic tape as a cover for the clip.
Title: Re: EEVblog #553 - Mailbag
Post by: peter.mitchell on December 10, 2013, 03:52:47 pm
I have that chip Dave if you want it. Don't know how long it would take to get there from the UK at this time of year but if you want to do a follow-up to that mailbag and get the thing working, I can stick it in the post for you.

Jon.

My experience with UK-> Aus any time of year is very quick. I'd say it would take a week, maybe 2, tops.
Title: Re: EEVblog #553 - Mailbag
Post by: beounet on December 13, 2013, 09:07:15 pm
 
Hey Dave!! About the camera zoom issue, why don't you make a foot-pedal zoom switch????
Title: Re: EEVblog #553 - Mailbag
Post by: delmadord on December 27, 2013, 08:36:19 pm
Just a quick GIF
(http://d24w6bsrhbeh9d.cloudfront.net/photo/a09o5vO_460sa.gif)
Title: Re: EEVblog #553 - Mailbag
Post by: delmadord on January 08, 2014, 10:36:44 am
and just one more pic

(http://seriouslyforreal.com/wp-content/uploads/2013/07/83420489.jpg)
Title: Re: EEVblog #553 - Mailbag
Post by: wilheldp on January 08, 2014, 06:33:23 pm
As crazy/stupid as some people are with body modification, it would surprise me if a craze started where people were trying to get struck by lightning to get a "cool" Lichtenberg figure "tattoo."
Title: Re: EEVblog #553 - Mailbag
Post by: SeanB on January 08, 2014, 06:56:07 pm
At least that would be self limiting, most do not survive the experience.
Title: Re: EEVblog #553 - Mailbag
Post by: IanJ on January 08, 2014, 07:17:14 pm
As crazy/stupid as some people are with body modification, it would surprise me if a craze started where people were trying to get struck by lightning to get a "cool" Lichtenberg figure "tattoo."

If Doc Brown can do it (albeit unintentionally) then surely Dave will give it a go........

(http://static1.wikia.nocookie.net/__cb20071115061110/bttf/images/c/c2/Bf1lightning.jpg)

Ian.