73 Amateur Radio Today – July 1970
Issue Contents:
Improved Color Slow-scan Television
– Using Polaroid films …… W4UMF 18
Worldwide ITU Prefix/call Area List
– Call prefix allocations …… W1SWX 24
The Super Autopatch
– Telephoning from your FM mobile …… K6MVH 26
How to Build a Keyer
– And still retain your appliance-operator status …… W9KXJ 36
A 2-channel Search- Lock for FM Receivers
– Listening to two repeaters at once …… W3DTN 38
A Look at Allied’s Portable FM Receivers
– Under $20 …… K9STH 44
450 MHz Mighty Mite
– One transistor superregenerative receiver …… K9VXL 46
Cheapie 6-meter Half-gallon
– Use 811-as and be heard …… K1CLL 48
A High Performance Power Supply
– Using an IC voltage regulator …… K0ECF/7 54
A Soldering Gun Tip
– New SCR-522 conversion article …… WB6PKA 59
Latham Island DXpedition
– This Zanzibar isle is for the birds …… 5H3LV 60
Study Guide For Your General Class License: Part I
– Okay Techs here it is! …… Staff 66
DB to Power
…… WA3JBN 85
Protection For Grid Dipper Coils
– Low-cost insurance policy …… WA0ABI 88
Mobile CW Receiver
– But where do you mount the code mill? …… W6BLZ 90
QSLing Ham Radio’s Own Con Game
– Not for pecuniar interest eh? …… VK4SS 96
73 Amateur Radio Today – July 1970
