Supplied Ready-made, or homebrew your own
RTTY Keyboard Adapter small PIC based adapter for using a PC keyboard to generate
raw 5V logic level 45 baud RTTY data. Can be used in parallel with the NUE-PSK Modem with a subset of common control codes.
Includes a type ahead buffer to allow for fast typists
PCB layouts, circuit diagram and PIC .HEX code. I'm not making the source code availalble, SRI Folks !
DTMF Remote Controller
DTMF Remote control over a telephone line.
This article was first published in Radio Communication in August 2001
JNT001 Transverter interface for IC202, FT290 or similar. PIN Diode Tx / Rx switching,
switched power rails and 21V vsupply for coax relays. This rather ancient design first appeared in 1992
JNT004 1296MHz Transverter ModuleThis was originally published in RadCom June/July 1994
Transverter Head Unit Control & Switching Module Sequencer, 28V supply for relays,
Protected +/- supplies for LNAs
OPA_AllPAss.xls All-Pass network design spreadsheet
144MHz Direct Conversion Receiver
Simple design with I/Q outputs for the RF front end of a sofware defined radio
Also useable stand-alone unit for beacon monitoring and signal measurements .
This article was first published in Radio Communication November 2004
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