That calculator kit is brilliant I have built it, very simple and it is a 4 band or 5 band resistor calculator as well as other functions

Your mailbag episodes are always cool and interesting. Many thanks.

If you have something like a bluetooth receiver on the same power supply as some little amp/speaker system -- the 0505 can keep that nasty RF (common mode?) noise out. A big calculator with cherry keys, that doubles as a PC numeric keypad would be nice. Build kits until your back hurts!

If you haven't seen them, there are small modules that convert 12vdc to adjustable high voltage. I think they are usually marketed as nixie tube power modules. Add in an adjustable buck module to bring the 12vdc down to 6.3 volts for the heater and you could power it all from a single 12vdc adapter.

Hi, the most interesting kit is the calculator. I though it would have an ultra rare LCD display (I mean the golden/black display found on the old Toshiba or Chinese calculators) but when you unboxed the LCD it seems a normal Arduino LCD display. The question is : how can a 3V battery coin power that LCD display ? 🤔 I imagine that with the battery it will last 3 minutes.... The instruction page seems to say NEVER plug the external power with the battery coin inserted (but I am sure 100% people will have plugged the external cable without removing the coin cell destroying everything... 😂) If you assemble this kit, let us know how much it works with the 3V coin battery 😉

Talking about kits , I haven't seen a clock kit in your mailbag videos. I've watched all the mailbag videos (twice). A clock is what everybody needs (and uses)............

@pileofstuff

4 ай бұрын

I did actually get a clock kit. It's in the queue for later this year. kzread.info/dash/bejne/dWd_uNyOY6e2YLg.html

Also, a long time ago, 1985, I built a valve amp and used several small power transformers to get the HV , one transformer was 3A multi tap that supplied 6V filament voltage, the same transformer supplied 12v to a scavenged clock radio power Transformers secondary winding and gave me a low current 240v output. A bridge rectifier and some suitable capacitors and I was up and running, It wouldn't have won any prizes, but it worked , I was able to adjust the voltage by selecting different tapping points.

@pileofstuff

5 ай бұрын

I've worked with similar multi-tap transformers in the past as well. Unfortunately, these days those are ridiculously expensive.

They love putting Canadian tourist ads on this channel - lol -. I bought a AE boost module/circuit that is something like 12V to 600V, and I think it can go as low 170V.

I isolate my grounds so when I'm out walking the pesky wife can't find me... more pub time.

Those isolated DC-DC's are a nice way to isolate bluetooth audio modules from amplifiers. Removes the nasty noise created by the module when it's differential outputs are referenced to power supply GND.

I have a similar mp3 player, glad you found reference to file naming being numerical, if it worls like mine, you can play midi files as in .mid, but not a midi input as such I also have a tube display, it's a short bar at each end that closes on the peaks, except mine is stereo, you may need a pre amp depending on what the circuit is. I got a second hand radio transformer with the high voltage and 6.3v windings from ebay If the transformer has a 240v winding, a half wave retifier would be suitable with a good smoothing cap.

Cool haul.! A buddy and me bult 6 of those tube amps, no joy. We spent months working on them, trading ideas over the radio, talking with department heads at uni. They're in the parts bin now. Can't wait to see how yours works out.

I just did a build of that calculator on my channel. Nice build and it works well too. Needs a battery upgrade though. Video 0153. It has a good HEX Decimal conversion.

@ElmerFuddGun

5 ай бұрын

I just watched your calculator build video. Too bad it doesn't have a plug in for DC power. And it was weird that you couldn't get the square root of the number already on the display.

@uni-byte

5 ай бұрын

@@ElmerFuddGun Thanks for watching. Yeah, It's no HP 41C and it does leave a lot to be desired, but it's still a nice kit build. I have mine at the ready and really only use it for HEX to decimal conversions which it does fairly well. I do plan to put a rechargeable lithium ion battery in it and a BMS module. Just to do it..

If that calculator is the same as the one I built, it has a resistor mode with 3 band/4 band/5 band input with the colour values on the keys, and it displays in Ohms, Kilo-ohms and Megaohms. It's really useful.

@MothKeeper

5 ай бұрын

Yeah... it's not the same.

@frankowalker4662

5 ай бұрын

@@MothKeeper Still, you can never have too many calculators.

I get most of my metric hardware from disassembly of discarded electronic gadgets. I harvest motors, steppers, rails,etc from printers. Only the USA uses "Imperial" and nothing is made in the USA now days, so basically anything you pull apart is full of metric bolts and screws.

Thanks pileofstuff.

What an interesting mix of items! 👍😀

Man your show going to rock!

I love the EM84 VU Valve. I've made quite a few projects with them. They look so funky.

@douro20

5 ай бұрын

The 6E2 is actually closer to an EM87. It is pin compatible with an EM84 but its electrical characteristics are somewhat different. I think one has more gain than the other.

That looks like a resistor calculator I built a couple of years ago. The case is different. The buttons are super fiddly to get into the holes. Before soldering each button make sure the legs are perfect even before inserting. Thanks again. Take care.

@pileofstuff

5 ай бұрын

Thanks for the tip.

Don't think I've seen any kit builds since December

@pileofstuff

5 ай бұрын

I ran out of kits to build after December. I'm restocking and should be doing one next month.

I built that calculator it works fine and the colour coded buttons gives you resistance of surface mount resistors a bit of fun🙂

@Hasitier

5 ай бұрын

I also ordered this kit especially for the resistor color code function. I’d like to see your build on it as I have to build one myself soon I think.

That calculator is interesting. I have that mp3 player, but never got around to playing with it.

all those dfplayer style sound trigger chips are a huuuuuuuuuuge pain in the bum. they might have uart control but you can't use it while it's playing any sounds, it will cause horrendous noises. eventually got the one i had under control but they really are for super simple applications. seriously, if you wanna conditionally play, say, 1 of 4 sounds, having all the files numbered in the right place and everything is a huge ordeal. they're best used in auto mode, it's designed for messages on busses and stuff about safety and routes. the midi one you're thinking of is probably the vlsi semiconductor vs1053 and friends. that's a whole codec chip that does a ton of stuff & has loadable software modules

I look forward to a Canadian Speak and Spell.

@AsilarWindsailor

5 ай бұрын

Ben Heck has been summoned!

Odd that in a country where the law says you shall work in metric, metric hardware is so expensive...

@pileofstuff

5 ай бұрын

A lot of construction materials and related hardware is still in US measurements. Part of it is for backward comparability, Part of it is that the manufacturers on this continent supply both the Canadian and the (much larger) US market. Stuff imported from overseas tends to cost more to get here, unfortunately.

Always nice to have an anonymous donor :) Btw.. did someone already ask why you have a piece of red tape on your scalpel?

@pileofstuff

5 ай бұрын

the tape adds a bit of thickness to the handle so I can pick it up off the desktop easier.

@DustinWatts

5 ай бұрын

@@pileofstuff Asked and answered :)

I don't think I've ever seen you build anything (kits don't count)?

@pileofstuff

5 ай бұрын

There's several in my video history over the last 7 years.

What's the difference between the first modules you unpacked and an optocoupler?

@geirendre

5 ай бұрын

The DC-DC module can deliver power to drive a unit, like the XY-V17B MP3 module. You might need that if you connect the MP3 module to a mains powered unit, this is to avoid ground hum. The optocoupler only isolates a small signal and requires some circuit on both sides of it.

@MothKeeper

5 ай бұрын

The opto's are coupled 👍

@pileofstuff

5 ай бұрын

These are for power supply use. An opto-coupler is to pass signals (not power) across an isolation gap.

Paid 17$ for a calculator.. i think i saw a pack of 10 for 20$ the other day.. lol

@johncoops6897

5 ай бұрын

It's not a standard numerical calculator. Anyway, almost any electronics kit will be more expensive than buying pre-built.

@pileofstuff

5 ай бұрын

Of course, but that's not the point.