HF Transceiver

HF TRANSCEIVER
by EI9GQ

This page will describe the construction of a multi band SSB transceiver. Because I do 99% of my operating on my four favourite bands, I decided to build a four band rig with provision for adding a fifth band later. The design can be used on any band from 160M to 10M. Mine covers 80M, 40M, 17M, 10M.

Block Diagram

SIMPLIFIED BLOCK DIAGRAM

This is definitely not a project for the beginner. I will only provide a circuit diagram and a brief description of each part of the transceiver. The construction details and choice of construction method, PCB, ugly construction, Stripboard, etc, are left to the individual constructor.

Band Pass Filter
Oscillator/Modulator unit
RX/TX Mixer
TX Amp
I.F. Amplifier
AGC
VFO
Driver amplifier
Receive audio amplifier
Final amplifier
Low pass filter
Digital display and VFO stabiliser

I've been using this rig for the last few months. I've had a lot of good reports about the transmit audio quality. So far, I've had no bad reports at all! I have added another band. The rig now covers 80, 40, 20, 17 and 10M. I haven't bothered to build a receive RF amplifier. RX sensitivity is very good on all bands from 80 to 17M. When the Autumn arrives, I'll probably build a receive RF amplifier for use on 10M.