I took the direct conversion receiver from two posts ago and converted it to a superhet receiver for 20 meters. The front end starts with a simple 2n3904 rf amp that feeds into a 20 meter band pass filter. ( Ignore the 40 meter band pass. I may add band switching later.) The band pass feeds into an sbl-1 mixer. An arduino/si5351 provides the vfo/bfo. There are two identical if amps (schematic below, found on n6qw.

So, while I was stuck at home sheltering from the winds of hurricane Irma, I knocked together a direct conversion receiver. I started with the audio amp that I built a while back. I added an SBL-1 mixer and an arduino/si5351 vfo. I then connected the RF amp from the previous post. I connected it to my 20 meter attic dipole and it received okay, but was pretty noisy. Probably because of all the alligator leads and bad connections.

I ran across a youtube channel by a guy named Charlie Morris, and it has inspired me to attempt to homebrew a new SSB transceiver. He is currently doing a series of videos of a homebrew superhet transciever from scratch. I finally had a bit of free time last night to work on something, so I put together Charlie’s RF amp. Here is the schematic. It his video, he goes over the calculations for finding the values of the various components in the amplifier, but I just went with what he used.

I finally got an ft8 qso with the bench top bitx. The first few times I tried, including in my last ft8 post, I was manually engaging the ptt with a push button. That got old fast, so I found a vox ptt interface that I could replicate with parts I had on hand. The DuinoVOX is a homebrew device that replicates the features of the Signalink interface. I slapped my own version together this weekend with this usb sound card and an arduino pro mini.

I’m working on an arduino morse code keyer and will be using a 16×2 lcd like this: I want to have some static text on the top line, while the bottom line scrolls. The built in arduino lcd library will do scrolling, but not a single line. There are other code examples showing how to do this, but they all seem overly complicated to me. Here is the solution that I came up with.

I wanted to try out the new ft8 digital mode this weekend, but things just did not go my way. First, I accidentally put 24 volts into my star wars bitx. I popped a few capacitors and burnt a few resistors, but it looks like the boards themselves are okay. I then rigged up the module itself on the bench with my signal generator acting as the vfo, but I wasn’t getting anything.