Following the decision to start another Hybrid SSB rig, it might be well to elaborate on some of the details. The first detail entails refining some of the features of the original 40M Hybrid Wireless Rig.
First is the change to 20M and the addition of AGC. Sure, I could ride the RF Gain Control, but at this stage of life I want something a bit more "automatic". A big development effort involves modifying the JF3HZB sketch to include sideband selection. Finally, is to add a tube final so you would have about 25 to 30 watts at the output. The Driver and Audio Amp would remain solid-state and likewise for the Digital LO and BFO.
The Devices would include the following:
12BA6 Receiver RF Amp
6BE6 Receiver Mixer
12BZ6 1st IF Amp
12BA6 2nd IF Amp
12AX7 Product Detector and Audio Pre-Amp
12AU7 Microphone Amp
6JH8 Balanced Modulator
12BE6 Transmit Mixer
12GE5 Transmit Final
2N2222A + 2N3053 Transmit Driver Stage
2N3904 + LM380 Audio Amp Stage
ESP32 + Si5351 for the LO and BFO
The circuitry would also employ two separate Band Pass Filters to simplify the RF switching. An interesting tidbit is that only one tube is common for both Transmit and Receive and that vacuum tube is the 12BZ6 which is the 1st IF Amp stage.
I have a Heathkit 3.395 MHz Crystal Filter and am looking to use that unit. This also offers the opportunity for building the rig for 17M. There is such a filter on eBay right now for $22. This is competitive with the cost of a homebrew filter and avoids the use of the questionable Nano VNA's.
The power source would be the Heathkit HP-23 supply + a 12VDC @ 5 Amps supply for the Filaments and the Solid-State Devices.
Them that know can make things go.
73's
Pete N6QW