I am probably a pretty weird duck, I like to build simple HAM equipment and radios and kits that I cannot use because I don’t have a license and I currently live in a country where, even if I was certified, still could not have a radio station. But I want to post some about my toys anyway. It is very satisfying to build a little radio from some schematic or solder up a kit and see it work.
Michigan Mighty Mite 40 meter radio for cw
Here is my Michigan Mighty Mite 40 meter transmitter that puts out about 500 mW on an 11.1 volt lipo. I bought the key in an antique store in Harbin, China. Recently I was playing with it (with the antenna going into a 50 ohm resistor) when a chunk of solder fell out of the bottom of the circuit board. So it stopped working. Then I discovered about 4 problems with the board and was amazed it worked at all. Fortunately I have an rf probe I built so tracked down all the issues and now it works great waiting for a day when I can really use it.
HAM CW keyer – chinese from 1950s I suppose.
Closeup photo of my chinese keyer from the 1950s I suppose.
QRP manual days antenna tuner
Here is an antenna tuner kit I put together which is interesting in that it cannot possibly work because the circuit board is wrong. This kit is known as the “manual days” QRP antenna tuner. The circuit board has a capacitor with one of the leads connected to the wrong side of the diode so it dumps any RF to ground and never reaches the LED to indicate VSWR. You can verify this for yourself by looking at the online schematic and online closeup of the board. I got it working but probably wont use it with my little QRP radios as it steals too much power from my 500 mW radios, probably better to just use an appropriate length of antenna wire.
HAM Pixie 2 40 meter transceiver
Here is my Pixie 2 40 meter transciever. I built two kits because I wanted the practice before attempting my RockMite and because the kits only cost 3 dollars here in china (cheaper than buying the parts separately. On one of the kits I inadvertently bent one of the LM386 pins under and missed the hole in the circuit board. Then I compounded the problem by trying to drill a hole through and soldering directly which in effect grounded that pin to the board. So had to hard wire to that pin and cut a trace, what a mess but lesson learned – I check all socket pins before I solder them.
HAM Octopus RockMite
Pictured above is my latest project, the Octopus RockMite kit I bought for about 15 dollars and a nice aluminum case for another 8 dollars – electronic stuff is really cheap here on http://www.taobao.com.
Already made mistake on soldering this board, I was using an old version schematic with a new version circuit board. Had to pull out 5 capacitors and start again. Now I have the right schematic. Didn’t come with kit, had to find it myself on internet. Put all the 104 caps in today and IC sockets.