I recently came a cross the four state qrp group’s ns-40 kit and it looked interesting. The kit has now been retired, but the schematic is available and I had everything I needed to build the circuit, so I slapped it together on a breadboard. This is basically just a proof of concept for me to make sure that I could get the circuit oscillating. I had it plugged into the paint can dummy load and I am keying it with that little push button.

While working on my bitx, I was in need of a 20 meter antenna. I strung up a quick dipole. but it didn’t work very well. I’ve been meaning to put together a multiband antenna for a while and since I had pretty much everything I would need, I built a G5RV antenna. More information about the G5RV antenna, including formulas, measurements, etc, can be found here. The basic parts that I used were:

After an extremely lucky craigslist score, I am now the proud owner of a Heathkit HW-101 and accompanying HP-23B power supply. According to the previous owner, everything worked when it was put into storage, but I’m going to clean it up and restore it with new caps and any other parts that are out of spec. I’ve been fighting with my bitx project for a little too long, so I think I’ll put it to the side for a while and get this up and running.

I’ve started looking back into software defined radio, specifically, the rtl-sdr dongles. I’ve got a few, but haven’t done much with them. I built a simple upconverter a while back, but I built it on a breadboard and it has since been disassembled. I actually bought a ham-it-up upconverter, but it was damaged in shipping and was refunded, so I never actually received it. Anyway, in researching upconverters, I ran across a mod to use the dongle in direct sample mode.

The bandpass filter for the bitx is now complete. While I’ve been building the bitx, I’ve been checking other build logs as I go along. One that has been helpful is PA1ED’s deadbug style bitx build. I decided to build the same bandpass filter that he used which is actually from version 1 of the bitx. You can find more info here. Here is the whole layout as of now. I slapped together a simple 20 meter dipole and strung it from my front porch out to a tree.

I’ve got the main bitx board built enough to test, so now I need the bfo and vfo. I put together an arduino nano, an si5351 breakout board, and a small oled display on a breadboard. I modified some of the vfo code I’ve used before and soldered clk0 and clk2 to the bitx with some rg174 coax. I don’t have a 20 meter antenna up yet, so I can only test with a signal generator.