EEVblog #1330 - Mailbag

[EEVblog]

Mailbag with new guest lab backdrops!



SPOILERS:
00:00 - Inside Ian Johnston's Lab!
https://www.ianjohnston.com/
03:16 - Err, Nothing...
04:49 - Google Nest Mini Teardown, ripoff Airpods teardown, Bose speakers.
12:14 - Sinclair C5 Brochure
18:08 - Inside Yunus KURBAN's Ecay Geophysical Solutions Lab
https://www.ecay.com.tr/
20:39 - IBM bank magnetic card reader teardown, weather station transmitter teardown
28:08 - Old School Archer Radio Shack dry etch PCB transfer symbols. SPO-256-AL2 speech synthesis chip.
34:45 - 5 dollerydoo's
35:31 - CrowPi 2 Kickstarter with Sagan!
https://www.kickstarter.com/projects/elecrow/crowpi2-steam-education-platformand-raspberry-pi-laptop
https://www.elecrow.com/crowpi2-raspberry-pi-portable-laptop.html

[DrG]

Ahhh the SP0256-AL2...and right from the shack....thanks for the nostalgia. Still have mine, built to work off of a PC parallel port. At the time, it was pretty neat.

[rsjsouza]

The Keysight U1273A has a tonal continuity tester. I did a video a while ago.

[Teti]

Loved the episode, background with viewer's labs is a great idea. Camera angle just need a bit polishing. Why don't you try blue/green screen background for one episode and see which one works better?

[crisr]

I really wanted to see arrangement of the microphones on the Google Home mini... I wonder what is done acoustically for the far-field voice recognition. I use those at home and they are really convenient if you have "smart" lights, plugs and appliances. Even if not, when paired to external speakers they are also great for (asking for and) playing music. As far as security concerns go, I have mine on a separate network (does not help if Google wants to be evil, but it's an extra obstacle for hackers).

[SilverSolder]

Oh man, that speech chip... I wanted it soooo bad. It also reminded me of the voice recorder chip that came in the same packaging. Huge nostalgia rush from that one along with the circuit strips. Total shame that shack turned into a phone store then died.

Sure ordering parts online is nice and cheap, but I still miss walking into the store and looking at all stuff and getting ideas.

Their big forte was CB radios, scanners, and stereo / sound systems.  All of the above have died out with the appearance of the modern smartphone...   

[themadhippy]

Good to see sagan is getting a good musical education in rock,although you might have to worry if he starts asking about the jack.

[CChin254]

Here is the IC Identifications and (some) Block Diagrams of the devices torn down in this Mailbag:





[ Specified attachment is not available ]

[EEVblog]

Loved the episode, background with viewer's labs is a great idea. Camera angle just need a bit polishing. Why don't you try blue/green screen background for one episode and see which one works better?

Green screen will be worse, guaranteed.
The effectiveness of the background image will be dependent upon the actual photo.

[EEVblog]

Ahhh the SP0256-AL2...and right from the shack....thanks for the nostalgia. Still have mine, built to work off of a PC parallel port. At the time, it was pretty neat.

For the life of me I can't find my old parallel port prototype 

[mwarren2]

Once again a great Mailbag segment. Glad to see you got the backdrop working correctly for the viewer's labs! I've attached a couple pics of my "lab" (Ha!) It's actually a part of my HAM Shack in my home in Pittsburg, California, USA. Many of the power supplies on the upper shelf were self built and others were assembled with purchased sub assemblies. Much of the test equipment was purchased used from various sources. On the left is an HP 54200A Digitizing Oscilloscope above a Marconi 2955 Test Set. On the bench is an HP 8568B Spectrum Analyzer and my soldering work station. Above the work station, hanging from the top shelf, is a Heathkit VTVM which I built in the 1970's, still fully functional. On the shelf, left to right is a GW RF Signal Generator, a GW Function Gen/Freq. Counter above a GW Digital MultiMeter and below a homemade Freq. Display. Next is an HP 6432A Dual Output 0.25A power supply above a home built power supply based on the small 5A switching supply module available on Amazon, and a Astron 30A linear supply. Under the lamp is my home built 10.000 MHz TCXO reference oscillator. Finally are two linear supplies, a 12V/30A and a 5V/2A supply. I've also attached a pic of the other end of the bench which is my HF, VHF, UHF, DTV HAM radio equipment. The GW 100MHz 2-Channel oscilloscope is used as a station monitor. Modest compared to the two labs in this mailbag but it gets the job done for me. Thanks for all you do for the electronics ,community worldwide!
Stay Well
73
Mike Warren
W6MEW
Pittsburg, California, USA

[Bud]

@EEVBlog maybe you could do a couple of episodes with Jim William's and Bob Pease's desks as the backdrop. High res photos may be hard to find though.

[EEVblog]

Once again a great Mailbag segment. Glad to see you got the backdrop working correctly for the viewer's labs! I've attached a couple pics of my "lab" (Ha!) It's actually a part of my HAM Shack in my home in Pittsburg, California, USA. Many of the power supplies on the upper shelf were self built and others were assembled with purchased sub assemblies. Much of the test equipment was purchased used from various sources. On the left is an HP 54200A Digitizing Oscilloscope above a Marconi 2955 Test Set. On the bench is an HP 8568B Spectrum Analyzer and my soldering work station. Above the work station, hanging from the top shelf, is a Heathkit VTVM which I built in the 1970's, still fully functional. On the shelf, left to right is a GW RF Signal Generator, a GW Function Gen/Freq. Counter above a GW Digital MultiMeter and below a homemade Freq. Display. Next is an HP 6432A Dual Output 0.25A power supply above a home built power supply based on the small 5A switching supply module available on Amazon, and a Astron 30A linear supply. Under the lamp is my home built 10.000 MHz TCXO reference oscillator. Finally are two linear supplies, a 12V/30A and a 5V/2A supply. I've also attached a pic of the other end of the bench which is my HF, VHF, UHF, DTV HAM radio equipment. The GW 100MHz 2-Channel oscilloscope is used as a station monitor. Modest compared to the two labs in this mailbag but it gets the job done for me. Thanks for all you do for the electronics ,community worldwide!
Stay Well
73
Mike Warren
W6MEW
Pittsburg, California, USA (Attachment Link) (Attachment Link)

If you want these featured please send to eevblog+mailbag@gmail.com

[mwarren2]

If you want these featured please send to eevblog+mailbag@gmail.com

Thanks Dave. Will do.

[bsfeechannel]

I'm thrilled to see Sagan so conversant and at ease with Scratch, Python, Arduino, Raspberry Pi. How old is he? 9, 10? I'd encourage him to have his own channel and share his discoveries. He has apparently inherited his father's enthusiasm (Minecraaaaaaaaaaaaft!!!!!) and penchant for removing stickers. He'd be an inspiration for kids his age.

[Lord of nothing]

  Dear Mr. Dave
Sadly the Austrian Post refuse to send anything to Austrlia do to the Corona Panic. 
I had to eat my Good Pack my self but I swear you will receive some big Box full with Austrian Candy's!
 

[WN1X]

I bet the ferrite rod in the weather transmitter is for a low frequency lightning detection receiver.

[coppercone2]

did you consider a evil postal worker in regards to the empty box? whats with the yellow tape?

[SmokedComponent]

Those were some really perishable goods in that (now) empty box. See what happens when you don't open your mail in time...   

[Wollvieh]

The Coils at Yunus Kurban's Lab seem to be Helmholtz Coils. I'd guess for testing compassy things, as I don't see a Teltron Tube around.

[spicyjack]

The dry-etch transfers that I sent to Dave were the ones I used to etch this SP0256-AL2 board:

https://www.eevblog.com/forum/projects/first-eevblog-forums-post-homebrew-1986-vintage-gi-sp0256a-al2-speech-box/msg2797266/#msg2797266

Radio Shack also used to sell an etching kit that came with a bottle of ferric chloride inside of a plastic box.  You would mask up your PCB, fill up one half of the box with the ferric chloride, drop the PCB into the box, and come back in 20 minutes to see if all of the copper had etched off.  I remember waving a plastic knife in the solution to see if the copper had all etched off, but I don't remember what I did with the etching solution after I was done.

State of the art home-etching in the late 1980's included using a stand up etching tank with a bubbler (like from a fish tank), so that the tiny air bubbles would etch your board faster.