73 Amateur Radio Today – March 1971
Issue Contents:
Integrated Circuit Audio Filter
– Clean up that dirty audio with a filter …… W2EEY 12
Integrated Circuit Six Meter Converter
– Not for bigots with six unconverted meters …… WB4KMB 16
Trap-type Vertical Antennas
– Adding stubs for two meters. FM article …… W2EEY 18
Resurrecting Granddaddy
– Fun with a 1925 parametric amplifier …… K6BIJ 22
Digital Counters
– Five digit …… W0LMD 26
Identifying Surplus Electronic Equipment
– Military marking system …… W6DDB 37
The Horizontal-output Linear
– A $50 kilowatt amplifier? …… W2AOO 40
DX America First
– DXpedition to Maine …… K1OXK 43
Phone Patch: No Cost No Wires
– Phone patching is illegal in Rwanda. Too bad …… WA2EAW 49
Mt. Snow: To the Repeater
– On Skis – Our cover feature. An FM article …… K6MVH 54
Repeater Audio Mixer
– Another great FM article …… W1ELU 57
Something New in PC Construction
– Building with scissors …… WA1EJU 61
Switching Remote Linears
– Like in the car …… W0HFK 65
Digital RTTY Accessories
– Regenerative repeater stunt box speed conversion …… K5ZBA 66
The Coathanger Groundplane
– Two meters (FM!) …… K6MVH 72
General Class Study Course
– Part VII. Power and how to get it ….. Staff 74
Reading 5 Code RTTY in Binary
– Just what you’ve been waiting for …… WB2MPZ 93
Petitions to FCC – 220 MHz proposals
…… Staff 118
73 Amateur Radio Today – March 1971
