EEVblog #775 - Mailbag

[EEVblog]

Dave opens his mail. A potpourri of items this week.



SPOILERS:
The world's smallest digital dosimeter / Geiger counter, and it's open source!
https://github.com/shodanx/ultramicron
The Stick-Vise PCB Holder:
http://www.stickvise.com/
Russian nixie tube display
The 1962 Ferrari 250 GTO
Telsa merch
Buzz Aldrin's Mission To Mars
Old Hioki analog clamp meter teardown
Old analog VOM teardown
Citizen Pocket LCD TV
Texas Instruments SR-10 Electronic Slide Rule Teardown
JRC ADC chip datasheet: http://pdf1.alldatasheet.com/datasheet-pdf/view/7614/NJRC/NJU9203BD.html
Old PSU teardown

[retiredcaps]

That exact Tilquist DT-443 multimeter was first posted below back in May 23, 2013

https://www.eevblog.com/forum/testgear/first-teardown-how-old-is-my-multimeter-tillquist-dt-443/

http://reizero.biz/projects/multimeter/dt-443.php

There is a PTC in the meter.  It just above the HRC fuse, R107 and R108.

Fine Instruments, the original OEM, is also sold under other brands like Klein and UEI.  The UEI in Dave's $100 shootout is made by Fine Instruments.

http://www.finest.co.kr/pi.html#hd

The Fine 183 is original.

http://www.radiomuseum.org/r/fineinst_multimeter_183.html

More Fine multimeters resold as Tilquist.

https://www.eevblog.com/forum/testgear/tillquist-dt-447-true-rms-model-187-fine-instruments-corp/

PS.  The display looks nice and big with nice constrast and easy to read.

[retiredcaps]

With respect to the Tilquist copying the Fluke 87 look, recessed knob, etc, during that era, Appa Technologies did the same.  The Appa 105 also used the JRC ADC as is this thread.

https://www.eevblog.com/forum/testgear/iso-tech-(appa)-idm105-dmm/

Tektronix also resold Appa multimeters under their own brand name as well.  The DM252 is identical to the Appa 105.

http://www.use.com/images/s_3/Tektronix_DM252_Handheld_Digital_Multimeter_1db7aace46d4ccd0ffca.jpg

[rgammans]

Dave if your a fan / interested in Buzz's ideas you do know about:

http://buzzaldrin.com/an-evening-with-buzz-aldrin-hosted-by-ray-martin-sydney/

I won't be going on account of living in the Uk!. 

[GrandTheftAuto4life]

Too bad it would cost a fortune to bring my old power supply in to the mailbag, there are some metal can caps and i think it's 60's vintage.
Teardown would take some effort because there are diodes connected by pressfitting, so this would be quite a challenge.

It has some sort of overload protection using a relay because you can hear it click "off" when it's overloaded, and to reset it one just turn it off and on again.

[EEVblog]

With respect to the Tilquist copying the Fluke 87 look, recessed knob, etc, during that era, Appa Technologies did the same.  The Appa 105 also used the JRC ADC as is this thread.
https://www.eevblog.com/forum/testgear/iso-tech-(appa)-idm105-dmm/

Yep, I used to have one of those, was a heap of crap.

[EEVblog]

Dave if your a fan / interested in Buzz's ideas you do know about:
http://buzzaldrin.com/an-evening-with-buzz-aldrin-hosted-by-ray-martin-sydney/

Woah, thanks!
Tickets booked 

[steves]

Yes please. I could make good use of that meter to replace my old and crappier one that I managed to break yesterday. Located in Sydney. Thanks.

[99tito99]

'robot797' on YouTube noted that the first Russki vac tube: "it has released its vacuum".  Take a look it has the grey hair.

Cheers,
Mark
*******************************************

[EEVblog]

Yes please. I could make good use of that meter to replace my old and crappier one that I managed to break yesterday. Located in Sydney. Thanks.

Email me your snail mail address.

[AF6LJ]

It was cool to see my first calculator the TI SR-10 I bought it when I was in high school which made me the Coolest of the Cool in electronics class. I wasn't allowed to use it on tests since learning the slide rule was part of the lesson plan, but I was okay with that. One interesting bug the SR-10 had and why you may find the few that are left have worn on / off switches... Once and a while on power up the calculator would start counting up at roughly ten counts per second.
At the time I paid 105.99 USD for my SR-10.

Dave the Calculator you need to get and do a tear down on is the HP-65.
I had one and unlike the HP-41 (I had two) the HP-65 was well built and had a built in card reader. When I bought my first HP-41 I foolishly traded off my HP-65 for some now forgotten piece of test gear.

[German_EE]

The HP-65 came out when I was a 5th year high school student and I wrote to HP with a load of technical questions. HP in their wisdom thought that I was a prospective customer and my mother was quite surprised when an HP salesman turned up on the doorstep one morning. I got all my questions answered though, this was when HP was a real engineering company.

http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1974-05.pdf

[free_electron]

the car thing looks like a radio receiver for a modern car. it sits somewhere in the car while that 10 pin connector connects it to the control / display unit.

the twin tuner setup : the small tuner is an fm/am tuner while the big brick is most likely an XM tuner ( satellite radio )

[mux]

Man, people are sending in some really cool stuff of their own projects. I should really just send Dave one of my 100+ projects as well.

I'm debating. Do you now actively avoid people who have a second 'suck of the sav'? Because I'm about to get 50 units of a commercial project made that you'll probably find very interesting. But it will take at least a month before I can send it off. In the meantime I could send something else, but is that wise?

[EEVblog]

I'm debating. Do you now actively avoid people who have a second 'suck of the sav'?

Yep!

[mux]

Well then, you will only get my best project. Or I just bunch 20 projects together to fool you

[AF6LJ]

The HP-65 came out when I was a 5th year high school student and I wrote to HP with a load of technical questions. HP in their wisdom thought that I was a prospective customer and my mother was quite surprised when an HP salesman turned up on the doorstep one morning. I got all my questions answered though, this was when HP was a real engineering company.

http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1974-05.pdf

Cool Did you ever get one?

[mikro]

There is a spelling error on the description. Or there is a new company named "Telsa" 

[MattHollands]

Don't know if anyone is interested, but this episode inspired me to make my own Stick-Vise. Having never used a "real" Stick-Vise, I can't say mine is as good, but it seems good enough to me. Here is mine keepdevelopingprojects.files.wordpress.com/2015/08/finished1.jpg. And here is how I made it in less than an hour keepdevelopingprojects.wordpress.com/2015/08/16/mini-project-home-made-stick-vise/.

[AccountRemovedPerUsersRequest]

I had exactly the same DIY idea. I made the first version about the same way as you described. It works but does not look so good. For the second version I used router and milled the PCB-holder using 5mm hard wood.

Axel.

[AccountRemovedPerUsersRequest]

Some photos of the finished holder attached as well as STL file in case someone likes to 3D print or mill one too...

Axel.

[MattHollands]

I'll admit it looks nicer than mine! But I don't have nice hardwood, nor a decent router , so I gotta make do