73 Amateur Radio Today – October 1979
Issue Contents:
Extremely Low Frequency Radiation: Cause for Worry?
– studies on ELF are inconclusive but the battle is joined …… WB2NEL 34
An LED Display for the HW-2036
– eliminates unwieldy thumbwheel switches …… WA4BZP 36
It’s a Wattmeter… It’s an Swr Bridge.. It’s Swattmeter!
– a super home-brew project …… K4LBY 42
The Double-sawbuck QRM Annihilator
– 3-iC circuit yields perfect CW …… WA5QAP 50
Center Insulator for your Next Antenna
– do it yourself with PVC …… AC5P 52
Another Approach to Repeater Control
– uses 7516 chip for low parts count …… W7JSW 54
Yes You Can Build this Synthesizer!
– keep your crystal rig …… WB2BWJ 58
Analog Telemetry Techniques
– while designed for medical signals these circuits work with any analog data …… K4IPV 68
The MICROSIZER: Computerized Frequency Control
– a synthesized vfo replacement for most HF rigs …… N4ES W4BF 74
CW Fans: Give Superior Selectivity to your Atlas Rig
– this mod uses an inexpensive MFJ filter …… WB9WWM 90
A Sensible CMOS TT Decoder
– presented by popular demand …… N6WA 98
DTMFR for your Repeater
– state-of-the-art TT decoding …… K4ALS 102
Freedom Fighters on Forty
– SWLing the anti-castro clandestines …… KA5M 108
The Miserly Mobile PVC Special
– radiates a very economical signal …… AA4RH 112
FSK Fix for the 820S
– the RTTY relay remedy …… W1PN 114
Einstein Was Wrong!
– this story has a Mobius twist …… Phenix 116
An 8-bit DPDT Digital Switch
– many uses …… W1SNN 130
Get a Piece of The Rock
– a DXpedition to Gibraltar …… W9JVF/ZB2CS 136
Easy-to-build 220 Transverter
– simple hookup to any synthesized 2m rig …… WA7SPR 142
73 Amateur Radio Today – October 1979
