EEVblog #906 - Mailbag

More Mailbag

SPOILERS:
Amateur HAM Radio Study Guides from Dan Romanchik
PCBite professional PCB holder
Accurate panel meter:
Valve Bonanza
Turns your PSU into a USB charger:
OP.A FM Synthesiser Arduino Shield:
Flip Dot Displays

Lumintop TD16 1000 lumens Tactical Flashlight Torch:
Worm AAA Keyring Torch:
Worm Brass:

Support the EEVblog through Patreon!

EEVblog Amazon Store (Dave gets a cut):

[Henchman]

I think this format is a good balance of speed and detail!

[SuperAWaC]

those rca tubes were for us military applications, hence the compliance, and the packaging

[lightguy]

I think the mirror on the PCB holder is so you can see the bottom of the board without having to completely flip the entire thing.

[galileo_rs]

Ham radio licence etc: For most of the people (these days anyway), the reason to get a licence is to be able to (legally) experiment with RF transmissions. I got my licence when I got the rtlsdr and when I learned about WSPR. There is something appealing (at least to me) in transmitting a 0.5W signal and getting that signal decoded a 1000 km away. Also lots of other interesting things to experiment with. So in a nutshell: experimentation with RF.

[bytesabre]

I want a clock made out of those flippy dot things now, just to be more hipster than the folk with Nixie tube ones...

[aljowen]

Presumably the mirror finish is so you can see both sides of the board easily.

[brycemw]

I think that the "Warning may contain Internet" is from a numberphile video where they unboxed something that said "Warning may contain numbers".

[BoltClevo]

The reflecting surface would be good on that board holder to power up prototypes with the thermal imager looking at both the top and bottom at the same time. Could be handy...

[pshq]

These lovely FlippyDot Displays are produced in Poland and are used here in almost all city transport busses. They're indeed really nice things. Even when a bus speeds through a road full of holes, these tiny dots doesn't flip! I'm being amazed by them everyday :)

[joedempseysr.]

The 6AQ5A vacuum tube was designed as the horizontal sweep amplifier for NTSC television sets in the '60s. They have an input power of about 15 Watts and an output power of up to 5 Watts. Plenty beefy to drive the horizontal sweep of a CRT.

These are fairly common and have been pressed into service by the Ham Radio community for use as QRP CW transmitters. I built a crystal controlled CW transmitter for the 40 Meter Amateur Band. With about 5 Watts output into a 40 Meter dipole antenna, I was able to work a station in Flint, Michigan from my home near Philadelphia, Pennsylvania. Not too shabby for a little 1 bottle CW QRP rig! I've got the plans for this little XMTR from a Electronics magazine from, I believe 1967. I'll e-mail you a copy when I find it.

Great job on the mailbag segments! Enjoy your YouTube channel immensely!
Cheers and 73! Joe, Media, Pennsylvania

[sotosz]

Hi, all Sotos here:

About the Panel meter case, I found it in a Chinese factory that manufactures display enclosure boxes . The PCB was built having already the enclosure and not the other way around...

[mirkomueller]

The pcb board holder looks fantastic. Great idea also the mirror surface so you also have a look under the board. Very well engineered. Love it...

[SatyajitRoy]

Mirror finished PCByte is good because you can see the underneath of the PCB quite easily.

[cypherfx]

The 5751 tube is probably worth at least $50 US if it's good. The JAN (made for military) black plate phillips ones can be over $150 each. 6HG5, is common and about $10, 5749 is $5, The 6350 runs about $25. The 6AK6 is another $5. The 6BC7 is cheap, The last one you didn't give the correct model but it looks like a rectifier tube, maybe a 5AR4 which is a treat at $100+ for a quality US one.

[sensepeek]

Thanks Dave for the positive feedback of PCbite!

Updates made to the PCBite kit compared with the early sample Dave tested in this mailbag segment includes but are not limited to:

We include insulating washers so that you can power up your creations with even more comfort. These are placed on both top and bottom side of the jaw so that the board is protected.

Stronger neodymium magnet, for better experience when using an ESD mat to cover the base plate. There is a PTFE protection cap on the bottom to sustain low friction and protect the surface of the base plate.

Decreased height of the PCBites to improve ergonomics during long soldering sessions where you would rest hands on your bench for added support. Height is reduced with 10mm (0.4") while still retaining a wide jaw and perfect grip. The PCB is held 55mm (2.16") above your workbench.

Mirror polish on one side and matte(B2) polish on the other side of the base plate, yes we just decided :-)

And regarding the price, the price on Indiegogo now include worldwide shipping and all of the above updates.

/Johan Hellman - Team PCBite @ Sensepeek

[cadikaorade]

Dan Romanchik's study guide helped me get my Technician license. Thanks, Dan!

[JennyEverywhere]

There's three US ham licenses nowadays, Technician, General, and Extra. That's in ascending grades of privileges and difficulty of study. I worked my way up through each to Extra.

[robinkopetzky]

Thanks for showing the PCBite! Best design I ever seen! Way to go, Dave!!

[voltlog]

the pcb holder with magnets, such a neat idea. Anyone can put that together at home with very little cost. Nice!

[KBNUHamRadio]

Thanks for featuring my study guides, Dave. I love your show!