Small Wonders Labs - SW-40+

Steve Yates - AA5TB



Last Update: January 27, 2010

In early 2006 my wife bought me a SW-40+ kit. This 40m CW kit included a very well made circuit card and board components to put together. I scrounged the external parts and purchased a die-cast aluminum enclosure from Fry's Electronics, part number 1927957. After drilling all of the required holes I polished up the enclosure first with a wire brush on my drill motor and then with steel wool. It took a lot of "elbow grease" to shine it up but it has kept its finish for several months now with no other finish.

Full View Closed

Inside View 1

Inside View 2

Inside View 3

Inside View 4

Later I installed a NORCAL Keyer. This is a very inexpensive but sophisticated keyer. I would highly recommend one to place in your rig.


I have had a lot of fun with this little rig. With the stock components it would transmit at 2.5 Watts CW. However, I once accidently switched the lever on my J-38 straight key and left the rig transmitting for hours. The P.A. transistor burned itself up. During the repair I replaced the driver and P.A. transistors with beefier ones and I can now get 3 Watts output with 13.8V and 2.5 Watts with a 12V battery. I also installed a small heat sink to the P.A. transistor. I also increased the VFO's tuning range from about 7001 kHz to 7054 kHz.

During the Thanks Giving Holidays of 2009 I installed a Digital Dial frequency display in the unit. When a get a little more time I will detail my modifications to this rig and I will put up some photos of the rig with the new dial. But for now I will just say that this rig has had a lot of use in my ham shack. For a 40m QRP rig I have worked quite a bit of DX with it.