During the ARRL 2025 Hamvention and as part of the ACRI Four Days In May event, The Michigan Mighty Mite will have a REVIVAL. It is open to all. The FDIM has a Club night on Friday 16 May 2025 at the Holiday Inn in Fairborn, OH

The Michigan QRP Club will have a table at Club night. Bring you old, new, whatever MMM to Club night. We will have a set up that includes 12vdc power and a dummy load. You bring your MMM and a way to key it (could be a pair of wires). If your MMM can be heard on our receiver, you will get a very special award. Not sure what it will be yet because we are still working on budget. But it will be special. I promise. Receiver will probably my old K2 with a hunk of wire antenna. There are no other criteria other we can hear it. If it puts a ton of power, we don’t care. If is cute, we don’t care, If it is ugly, we don’y care. If it in an altoids tin, we don’t care.

amateur radio license required to operate on the air!


500mW CW TRANSMITTER

Author and technical wizard, Dave Ingram - K4TWJ. (SK), once wrote:?

A very quick and easy way to get on the air is to build a "Michigan Mighty Mite" CW transmitter for 160, 80, 40 or 30 meters originated by Ed Knoll, W3FQJ and developed by Tom Jurgens, KY8I. KY8I was one of the MIQRP’s founding members. It can't get?simpler than this! I made my very first QSOs with a 40-meter version. It has very few parts, costs almost nothing, and it works!

Output power is about 500 milliwatts with a 12-volt power supply. To operate, attach 50-ohm dummy load or appropriate 50-ohm antenna (do yourself a favor and use a half-wave dipole antenna to avoid?tuners and assure good results) and ground, insert crystal and close the key. Adjust the variable capacitor for the cleanest signal that has the most power (compromise).That's it! You're on the air, and can?confirm that it's working with field strength meter. Power output can be figured with a common multitester by using a very simple wattmeter circuit.



Q1:
2N3053, 2N2222, SK3265 or similar inexpensive general-purpose NPN transistor. I use a plastic-case transistor that came in a bargain-pack from Radio Shack - works fine. Use heat sink - try an alligator?clip if you don't have a heat sink handy.

TANK COIL:
use a 1.25" diameter form (35mm film canister, pill bottle, etc.) and #20 - #22 AWG enameled ("magnet") wire. To make tap, wind L1 to the "tapped at" number of turns (see table below). Make a loop about?1 inch long, twist it a few times and finish winding. Sand the insulation off the end of the loop. This is your tap. After winding L1, wrap it with a thin layer of masking tape and wind L2 on top of the tape in the?same direction as L1. Secure L2 with more tape and finish by sanding insulation off remaining leads.

? ? ? ? ? ??L1:?? ? ? ? ? ? ? ? ? ? ? ? ? ? ??L2:

(primary/collector windings)?? ? ? ??(secondary/antenna windings)
160m--60 turns, tapped at 20?? ? ? ??160m-- 8 turns
?80m--45 turns, tapped at 15? ? ? ? ??80m---6 turns
?40m--21 turns, tapped at 7?? ? ? ? ??40m---4 turns
?30m--15 turns, tapped at 6?? ? ? ? ??30m---4 turns
XTAL: fundamental-mode crystal for desired frequency.
About that variable capacitor - the unit in the photo is a discontinued item from Radio Shack, but NO PROBLEM - salvage one from an old transistor AM Radio or try a trimmer capacitor. Of course, a fullsize?variable will work - but it will also be bigger than the rest of the transmitter! Tracking down variable capacitors at a good price is a noble challenge and part of the game.

Source:
Ingram, Dave, K4TWJ, "World of Ideas: QRP Fun - Part II"?
? ? ? ? ? ? ? ? ? ? ?(CQ, Vol.48, No.3, March 1992, pp.107-108)

Ed

AB8DF

Ernie

W3ETE