KC8AON's QRP PROJECTS
SW-40+ QRP CW TRANSCEIVER

THIS IS THE FIRST TRANCEIVER KIT THAT I BUILT


This is my SW-40+ QRP CW transceiver from Small Wonder Labs. The SW series kit comes as a board and parts only kit, and you must supply things like the enclosure, the controls, power, key, and headphone jack, knobs, and othe misc hardware. The circuit board in the SW series are 2.8" x 4", and are top quality double sided, plated through holes and have parts numbers printed on them. Small Wonder Labs did sell an enclosure and hardware kit for the SW series at one time, but is no longer offered. I decided to order just the board and parts kit though since I had several surplus enclosures on hand that I had picked up at hamfests for next to nothing. Most of the other parts like the 2 control pots, the various jacks and switches were purchased at Radio Shack, and the knobs came from my junkbox. The finished product provides you with a very nice transceiver that has full breakin keying, a very sensitive receiver, and about 2 watts out of the transmitter. The SW series is a VFO controlled rig that covers about 35 khz of their respective band, and uses a potentiometer that controls the voltage to a varactor diode for tuning. The vfo can be modified to increase its tuning range by changing the value of one capacitor in the vfo. My SW-40+ covers 7.026 to 7.125 mhz for 99 khz of band coverage. When you do this mod, the tuning rate gets very sharp ! To fix this, simply install a ten turn pot to slow things back down. For dial calibration, you can use either a 10 turn counter knob and make up a chart to keep track of the frequencies, or just do what I did and use a regular knob with numbers on the front panel of the radio and count the turns yourself and then keep a chart handy. I did this because I plan on (someday) putting a Freqmite freq counter in it. I did install a TicK keyer inside the rig so that all I have to do is plug a set of paddles directly into the radio and I'm ready to send.

All in all, the finished product is a very dependable little QRP rig that is very battery friendly (about 16mA RX / 215mA TX) and provides a small package that you take almost anywhere ! I have enjoyed several hours of operating with my SW-40+, and it has never failed me once. If you are looking for an inexpensive QRP rig, the SW series kit is very hard to beat for the $55 shipped that Small Wonder Labs charges for these kits ! For more info about the SW series and other fine kits that Small Wonder Labs offers, just click on this link to go to direct to their site: Small Wonder Labs

 

NOTE: Just to make it clear, I don't work for Small Wonder Labs, and they don't pay me any commissions. I'm just a very satisfied customer !

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