I have a copy of the excellent book 'Solid State Design for the Radio Amateur'. This book, published by the ARRL in 1986, was devoted to QRP and homebrewing with many practical circuits included. As some RF components were hard to source in Australia years ago, it took me years to finally build a circuit published in this book! Many of the semiconductors used in the designs have gone out of production since the book's publication but thanks to the internet many of the parts can be sourced from 'new but old stock' worldwide. I guess this prompted me to finally build something.
My first attempt was a receiver I.F. amplifier with a hang AGC system which could be used as a building block in an SSB/CW receiver. That project is featured elsewhere in these pages. Its success spurred me on to try another design from the book.
The circuit board pictured below is that of a carrier oscillator, speech amplifier and balanced modulator for the Universal SSB transmitter featured in chapter 8 on page 203. It has a switched crystal carrier oscillator, MC1496P balanced mixer FET microphone preamplifier and an LM741 speech amplifier. Upon testing it worked as described and will form the basis for a future project.
From Solid State Design for the Radio Amateur. Written by W7ZOI and W1FB
Pictured below is three images of the next stages of the Universal SSB Transmitter. These are the 9MHz I.F. amplifier and transmit mixer. The circuit appears on page 204 of chapter 8. A gain controlled dual gate MOSFET amplifier is used either side of the crystal filter. The 40673 MOSFET is scarce and expensive these days and the ones from China are duds so I used MFE131 types sourced from old commercial VHF two-way radios.
The transmit mixer is an MC1496P followed by a broadband output transformer. From here I will drive a broadband amplifier followed by a selectable bandpass filter for the bands of interest.
Page last updated 25th April, 2018