EEVblog #1221 - Mailbag Monday

Mailbag Monday

SPOILERS:
Fran Blanche's Apollo DSKY T-Shirt
Ollie: Voice control for oscilloscopes
Soviet era MKU-1 Calculator New-In-Box!
Relay Timer design
Vintage HP PCB's

Bitcoin Donations: 38y7DE8HEHNj8fGDtUr4PkCn9nWxiorvvy
Litecoin: ML7oQokTwB38bgzzjLDbRV97HKAHuwRfHA
Ethereum: 0x11AceA38DCA9DbFfB4F35f3F746af65F9dED28ce

Support the EEVblog through Patreon!

Buy anything through that link and Dave gets a commission at no cost to you.

Stuff I recommend:

Donate With Bitcoin & Other Crypto Currencies!

[glenslick]

Hey Snips, Enhance 224 to 176. Enhance, stop. Move in, stop. Pull out, track right, stop. Center in, pull back. Stop. Track 45 right. Stop. Center and stop. Enhance 34 to 36. Pan right and pull back. Stop. Enhance 34 to 46. Pull back. Wait a minute, go right, stop. Enhance 57 to 19. Track 45 left. Stop. Enhance 15 to 23. Give me a hard copy right there.

[RasorG]

Hi, Dave.
This is the VFD ИВ-18 (IW-18) display, and this white stuff (some kind of paint) is 100% normal in this place :)
I have this display in a mint condition (it has never been soldered) and I also have a white coating exactly in this place (from the factory).
I think it's a kind of protective layer, because in this place, there are two Getter rings - and as you know, these have to be inductively heated.
As long as you have a black coating on the back glass, it means that it keeps the vacuum and the display should work!

Take a look at the fuse, replace the capacitors maybe, etc.

By the way, I must honestly admit that this calculator looks beautiful (i fell in love immediately;) ). Maybe the quality of the material from which the casing was made is not at the highest level, but when it comes to design, it looks great! A combination of white with black and green island (display) in the middle, simply looks clean and beautiful. This one beveled corner with which the power cord was lead out. Everything looks more modern than it really is;)

I wanted to add that I'm not Russian :) :)

Cheers!

[electrofan]

38:34 This is 4-phase clock generator for the main chip.
Also, I guess the VFD is OK (black stuff inside becomes white if there is air inside), try to power it up and check supply rails. 99% there is a problem in the power supply. It is very primitive, you can quickly find and fix the problem.

[HazeAnderson]

To be fair it takes me 2.5 seconds to translate your accent too. 😏

[SidneyCritic]

You gotta at least try to get the MKU-1 working.

[martynwelch]

2:49 I suspect the reason it's got dual mics is simply because it's a standard board that can be picked up fairly cheaply - the ReSpeaker 2-Mic Pi HAT.

[stephenbell]

The HP board is probably part of some telecom testing equipment. The 140MB/s rating is a standard bit rate for high order multiplex equipment which I worked on in the late 80's. The 75ohm input impedance is standard for this type of telecom equipment.

[vasilybulochkin]

Hi Dave!. Not sure if someone already said it. Chip on 38:35 is К165ГФ3 - 4 phase impulse generator. It have frequency range of 75-100kHz and was used in calculators.

[timballam]

Love the industry standard volume control on the buzzer :)

[meanwhileinmylab]

The timer is just for learning and fun. I used what I got, so it's a mix of SMD and through-hole. I wish you would discuss about the calibration like how to measure its frequency and calculate its trim value. It's all in the MCP7940N datasheet and I believe people would love to see it because it's very educational.

[Nik]

We still use hatchet fill on NFC readers, so it does not interfere with the antennas, but you still get some kind of polygon plaines.

[lp]

34:22 It says "Electronica MKU1".

[zaprodk]

That VFD is looking EXACTLY like it should. The white coating is to make sure the getter doesn't short out the parts it's not supposed to do. The silvering on the back of the tube is like it should be. Silver = Good. Gray/white, air got in = junk.

[freeman]

It's everyone's favorite segment, Mailbag!

[FranLab]

Repair that Calculator or give it to me! ☺

[linagee]

"Hey Snips, make my startup project successful."

[tzisorey]

*_Hey Snips_* - Move in... _stop_ ... track 45 right, center and stop ... enhance 34 to 36....

[emilybjoerk]

It can't steal power from the usb port because they are limited to 500mA 5V unless you use PD which I don't think your scopes have; and the RPi specs a 2A 5V supply iirc. Not that it uses it constantly but for peak usage and all the io you can attach.

[ViktorEviltronics]

RC Thing is part of "К165ГФ3" - 4-phase clock generator

[gudenau]

I tried to use snips before, couldn't make it work at all.

Edit:
The scope connection doesn't provide power. It's a device, so it can't. Only host can provide power. (OTG is both, kinda)