Ramsey Electronics PR20 - Manual (Page 11)

PR20—11
A 220 MHz “ACTIVE ANTENNA”
For situations where a simple indoor receiving antenna is needed, the PR20 preamp will add
considerably improved performance to a whip antenna adjusted to 1/4 or 5/8 wave. And, for
a very well engineered true active antenna for both HF and VHF at a break-through low
price, take a look at our new model AA7 Active Antenna kit which features an on-board
battery supply, adjustable gain control, heavy-duty whip, HF-VHF mode switching, and jack
for using external antennas.
T-R SWITCHING CONSIDERATIONS FOR TRANSCEIVER OPERATION
If you wish to use the same antenna for transmit and receive, T-R switching is, of course,
essential. The T-R switching may be any of the following:
•
manual in-line switch (NOT recommended for VHF/UHF)
•
relay controlled by push-to-talk line
•
RF sensing T-R relay (Ramsey Kit No. RFS-1)
•
PIN diode T-R switch
PIN diode applications are discussed in amateur radio magazines and the ARRL Handbook.