EEVblog #729 - Mailbag

[sergey]

Dave, you plugged the nixie wrong way around first time by the looks of it It is supposed to have cathode in the center pin and anode in the side pin. And yes, that was a date code. We absolutely produced nixies in 84 and think i even have ones with date code of 86.

The voltages are a bit weird on them. It is supposed to start glowing at 100v and keep glowing at 70v. That's per original specifications. Not totally sure about physics happening when they're living on the shelf, but maybe they're aging? Because i've got whole bunch of IN-12 and IN-4 here and all of them are starting to glow at a different voltage.

Macbeth, that a very neat resource, thanks for sharing it!

[barnacle2k]

Hmm this makes me want to play with my IN-13 tubes again (neon filled, orange/red glow).
And yes polarity matters on these.
Here another datasheet: http://www.die-wuestens.de/rb/IN9-13.pdf
And that APC NetBotz is actually meant for datacenter / server room monitoring not home automation. 
Thus the industrial construction.

[Sebzy]

The Netbotz monitor was used in a datacentre for 18 months before it just decided to die after a reboot, suspect it's switch mode power supply issue but thought it would be more entertaining to send it along for a tear down. Sure if you drive it from the on board DC jack it should boot up fine.

[Len]

44:30 - That RAPIDMAN may be made in Canada, but it's got an "Oz" button!   

[crisr]

And the oscilloscope in the background is still upside-down...

Maybe to recalibrate the internal reference crystal for the southern hemisfere... no need for a fancy AGO-3000 ;-)

On another topic, that WiFi cellphone charging Kickstarter has already got $50 worth of backers... if it was a flexible funding campaign maybe he could use that to buy some basic electricity textbook, or upgrade that RadioShack multimeter to a better one... yes, lots of confidence inspired by it next to the giant cardboard coil :-). Someone should pledge $5 just to be able to point that out in the comments section.

[D. Head]

And the oscilloscope in the background is still upside-down...

Maybe to recalibrate the internal reference crystal for the southern hemisfere... no need for a fancy AGO-3000 ;-)

In a other mailbag-video, the new employee walks in and turned the oscilloscope upside-down.

[Don Hills]

The oscilloscope in the background makes perfect sense to me... I'm left handed. 

[dr.diesel]

I'd love to see an EEVBlab of your calculator collection.   

[seb30]

Hi,
The logo on the calculator CPU make me think about French Thomson CSF.

SeB

[SeanB]

I also had that thought, and Thomson did make a lot of IC's for the European market, either as custom devices or as second source. They used to be a big player, but have now seemingly concentrated on the defence and avionics market as a source of obsoletium parts. they probably are the only supplier where the ceramic package is not the most expensive part to manufacture, though I guess they have large warehouses of NOS parts sitting in sealed packaging with dessicant sachets just for the spares market.

[richfiles]

I'd love to see an EEVBlab of your calculator collection.   

If I were to ever post videos of my own calculator collection... It wouldn't fit in a "blab" format! 
I count 39 desktop calculators just on display right now at my place! That doesn't include the pocket ones!

[Pentium100]

I have bought some IN-13 tubes to build an audio level meter (these will look better than magic eye tubes from further away), however, I could not figure out how to build a log converter using vacuum tubes (even with help), so now I will have to do it with transistors and opamps , then again, mounting the circuit board inside a 1U case will be easier than mounting tubes horizontally.