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Seeking 20M Transceiver schematic

Sep 25th 2021, 11:42

miner_tom

Joined: Sep 25th 2021, 11:09
Total Topics: 0
Total Posts: 0
I am an older EE.

I would like to start the design of a 20m homebuilt rig. I have seen a couple of examples, such as one by Gregory Charvat on Hackaday. However, some diagrams and "schematics" are provided in such a format as to be difficult to translate (no direction as to RF separation of stages).

Yes, some plans are old and I intend to update the designs from "through hole" to SMT technology.

I have lots of documentation such as "Solid State Design for the Amateur" and "Secrets of RF Design", and others, as well as decades of experience in electronics design.

What I am looking for is a decent design to start with, which I can schematize and substitute components and/or add features (like PLL's, AGC, etc.).

Thank You
Tom
Sep 27th 2021, 08:45

W1VT

Super Moderator

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
DEC 1989 - QST (PG. 18)
QRP SSB/CW Transceiver for 14 MHz, A Part 1
Author: Hayward, Wes, W7ZOI
JAN 1990 - QST (PG. 28)
QRP SSB/CW Transceiver for 14 MHz--Part 2, A
Author: Hayward, Wes, W7ZOI
http://www.arrl.org/arrl-periodicals-archive-search
ARRL members can use this web page to download old QST articles.

http://w7zoi.net/qststuff.html
Wes has a web site
Sep 1st, 17:18

N8ZRY

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
Hi Tom,
It is fairly daunting to begin the process but once you get your mind into it things flow. I suggest building the radio in 50 ohm modular blocks, that way you can test it with Nano VNA and Tiny SA as you go. The trouble with the old books is that they do not include advice on how to use modern parts, such as MMIC amplifiers and double balanced mixers from Mini Circuits. These modern parts are terrific. I still found that i had to use an older circuit for the variable gain amp for the purpose of having an AGC, the Motorola MC1350 is great IF amp chip for this purpose. These days you do not need crystal oscillators, you could just use an off-shelf DDS's and Arduino to control both the VFO and the BFO. Start by piecing things together, borrow bits from designs you like, feel free to use anything from my radios (the 20m SSB transceiver and the 6 & 10m SSB transceiver from Homebrew challenge III). Good luck and keep us posted! - Gregory Charvat, N8ZRY

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