Michigan Mighty Mite – Page 6 – SolderSmoke Daily News

Another NY Mighty Mite Oscillates — on 40! N2HTT (Video)

Inspired by all the talk of Mighty Mites, N2HTT put together a nice 40 meter version:

Details on his blog: http://n2htt.net/

Click on the video above to see and hear it in action.

Our book: “SolderSmoke — Global Adventures in Wireless Electronics” http://soldersmoke.com/book.htm Our coffee mugs, T-Shirts, bumper stickers: http://www.cafepress.com/SolderSmoke Our Book Store: http://astore.amazon.com/contracross-20

Manhattan Mighty Mite: “Rockin’ the Big Apple on 3.579”

Dave W2DAB got his Manhattan Mighty Mite oscillating nicely! Hooray!

Check out Dave’s report on his Mighty Mite adventure:

http://w2dab.bamford.net/

So far we have sent out 20 colorburst crystals. Already we have two circuits oscillating (not counting Pete’s and mine).

CLA is on the march!

E-mail from Dave:

Dear Bill & Pete:

Thanks for all your help, I can joyfully announce the birth of my first Michigan Mighty Mite, Oscillating at the frequency of 3.579! Yes, Pete’s sage advice to flip the coil over was a great help and also my good friend from Vermont (A Michiganian by birth ). OK, so Bill… you remember your most embarrassing moments in home-brew? Well, here’s mostly what happened: I was reading the article I found online and somehow got 40 meters stuck in my head even though your colorburst was for 80 – So I build a 40 meter coil. When I realized my mistake I thought – well why not build two of these so I pulled out the Colorburst and put in a Norcal 7.040 and then built a new board with a new 80 coil oriented properly and the pic below is the one you see. Now I have two Mighty Mite’s that work, how great is that.

My next goal is to continue forward using Pete’s Build Something Video’s, so more fun to come.

I will post a video on my blog of the 80 Meter Colorburst Michigan Mighty Mite uttering it’s joyful tones, but for now I’ve put a lovely photo at the bottom.

Success is sweet when you hear the sounds of the beep!

Cheers and 73 Gentlemen

Dave

W2DAB

(“Manhattan is more fun in Manhattan”)

Building a Better Diode Ring Balanced Modulator (with Knack Karma)

So yesterday Pete and I were talking about Dave W2DAB’s Michigan Mighty Mite malady. Dave is tantalizingly close to the joy of oscillation. Wizard that he is, I think Pete diagnosed the problem with his eyes closed from 3000 miles away. I sent Dr. Juliano’s prescription to Dave this morning and expect the concrete canyons of Upper Manhattan to be ringing with pure 800 Hz tones as soon as Dave fires up his soldering iron.

Anyway, I then told Pete that I’d been looking through my bookshelf for something suitable for my 11 year-old nephew Sebastian. I found something for him, but I also came across a book that was too advanced for the young fellow: “The Master Handbook of Ham Radio Circuits.” TAB Books, 1977. By “The Editors of 73 Magazine.” Between turkey sandwiches I started looking through this book. I immmediately found an article of interest: “A Better Balanced Modulator.” The author (unnamed) looks closely at the performance of our beloved and much-used diode ring mixer with dual trifilar transformers. He concludes that the unbalanced input and output coils (in the traditional configuration) detracts from the balance needed for optimum carrier suppression. He suggest the use of baluns at input and output (see above) and claims significant improvement in carrier suppression. Very interesting. (If anyone wants to dig into this, e-mail me.) There is also a very simple solid-state VFO circuit that promises phenomenal stability.

Anyway, I found myself trying to remember where this great book came from. Then I remembered someone sending it to me. A quick check of my e-mail revealed the source: Dave W2DAB sent it to me three years ago. Thanks again Dave!

Ben’s Mighty Mite — IT IS ALIVE!

Ben KD9JNQ is the first of the Colorburst Liberation Army (CLA) recruits to get his Michigan Mighty Mite to oscillate. So he has been promoted to Colonel.

Ben writes:

Bill and Pete, thanks again for the encouragement!

EL CLA UNIDO JAMAS SERA VENCIDO

Ben
KD9JNQ

Colorburst Explained

http://en.wikipedia.org/wiki/Colorburst

Bill’s Dominican Mighty Mite (1993)

If you look closely, just in front of my keyboard you can see the Michigan Mighty Mite that I rebuilt this morning (scroll down to see the previous post). Looks like I was using a polivaricon as the capacitor. Other than the cap, all the parts used in this 2014 version were from the 1993 effort. Here is how it is described in “SolderSmoke — Global Adventures in Wirless Electronics”:

I decided to start off slow, with small projects that seemed likely to succeed. The secretary in our office in the Embassy, Mady Bullen, had an interest in ham radio that had been sparked by service in far-off places where short-wave was the only way to talk to home. She would pass me old issues of CQ magazine. It was in the March 1992 issue that I found the Michigan Mighty Mite.

It was originated by Ed Knoll, W3FQJ and developed by Tom Jurgens, KY8I. It is about as simple as you can get in a radio transmitter: just one stage, a crystal controlled oscillator.

An oscillator is basically an amplifier in which some of the output signal is fed back into the input. If you provide enough feedback in the right way, the amplifier will “take off” and begin generating a signal. The howl you hear when the microphone of public address system gets too close to the speaker is this kind of signal. The speaker (the output) is sending energy back to the input (the microphone) and what was an amplifier turns (annoyingly) into an oscillator. In this case it is an audio frequency oscillator because all the filters and tuned circuits in the PA system are built for the audible frequencies. But the same thing will happen at radio frequencies. That’s what the Michigan Mighty Mite is all about.

I put the thing together using parts obtained from the Santo Domingo Radio Shack store. The resonant circuit used a coil that was just some wire wound around a discarded plastic 35mm film container. Homebrew radio projects rarely work the first time you power them up. I had to fidget with this thing quite a bit—obviously there wasn’t enough feedback. I had my Drake 2-B on and tuned to the crystal’s frequency. As I poked around on the little circuit board, I suddenly heard a little chirp from the 2-B. There it was! The little device that I had put together was producing radio frequency energy on the 40 meter band. Hooray! The joy of oscillation! Now I felt like I was truly in league with Faraday and Marconi, with Shep, Stan and Bollis, and with Serge! Hilmar would have been proud of me (but he still would have been horrified by my sloppy wiring).

I never was able to talk to anyone with that little device—the power output was very low, and my antenna for the 40 meter band was very poor. But it didn’t really matter. I had had my first real success at homebrewing a piece of ham radio gear.

Bill’s Re-Born 1993 ColorBurst Michigan Mighty Mite

So far we’ve sent out 9 of these color burst 3.579 MHz crystals. It occurred to me that I should make sure these particular rocks work with the Michigan Mighty Mite design we’ve been advocating. So today — still in something of a turkey-induced haze — I pulled out the surviving remnants of the MMM that I built back in 1993. That one had been for 40, so I rewound the coil for 80 using the data from this MMM site: http://www.qsl.net/wb5ude/kc6wdk/transmitter.html

I was hoping that this rig might oscillate even without the variable capacitor, but mine did not. Once the cap was placed in the circuit, the oscillations began. It sounds pretty good on my Drake 2B.

I have not yet wound the secondary (antenna) coil but (as I suspected) the oscillator works fine without it.

So, no excuses folks. These cheap junk box crystals work. Time to build one of these things and join the ranks of hams who have homebrewed a transmitter (and, of course, The ColorBurst Liberation Army).

Pete Builds a Michigan Mighty Mite

We have been distributing quite a few 3.579 MHz crystals, but until today we hadn’t seen a single new Michigan Mighty Mite. I commented on this in the last podcast. Pete came to the rescue and built one:

Hi Bill,

The MMM was built – took me a long time (about 30 Minutes so it was kind of slapped together). The most time was consumed drawing squares on the sheet metal. I used a pill bottle cut down for the coil.

Used a piece of Home Depot sheet metal for the based. I highly recommend a .01 Ufd from the 27 Ohm to ground –key clicks are awful.

BTW the circuit can be modified so that the tuning cap is soldered to one side of the coil and the other side to ground –essentially the tank tuning cap is in series with the 0.05 bypass cap and is effectively across the coil. Tribal Knowledge

The CLA lives on!

Pete

VIVA EL EJERCITO DE LA LIBERACION DEL COLORBURST! VIVA EL CLA!

Pete’s Michigan Mighty Mite Manhattan MePad Noodle

New recruits have been signing up for the Color Burst Liberation Army. We have been sending out many more 3.579 MHz crystals. Pete Juliano was doing some noodling and came up with this plan for Manhattan pads or Me(Maine)Pads. All you need is some copper clad board, a pair of Home Depot tin shears and some super glue. Cut out the pads, glue them down, add components and get the Mighty Mite percolating.