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AM/FM/SW Active Antenna: This circuit shows an active antenna that can be used
for AM, FM, and shortwave SW. On shortwave band this active antenna is comparable to a20 to30 foot wire antenna. This circuit uses receivers that use untuned wire antennas, such as inexpensive units and car radios. L1 can be selected for application (added
4/02)
An end-fed antenna: L-match coupler and resistive bridge for HF one wire, all bands
(design added 6/07)
Antennas: Ground Pole and Half-Wave Dipole Antennas (circuit added 10/06)
MW Active Antenna: This circuit is designed to amplify the input from a telescopic whip
antenna. The preamplifier is designed to cover the medium waveband from about 550Khz to 1650Khz. The tuning voltage required is 1 to 12 volts and can be obtained from a 10k potentiometer connected to the 12 Volt power supply. RV1 is the gain control allowing weak signals
to be amplified or strong signals to be attenuated. The control voltage is applied to gate 2 of TR1, a dual-gate MOSFET, the signal voltage applied via gate 1; .... (added 10/05)
