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Tuned MFJ-1024 Active Antenna
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August 16th 05, 04:16 AM
Dale Parfitt
Posts: n/a
"Telamon" wrote in message
...
In article .com,
wrote:
Hello Group
I have been wondering if it might be an advantage to remotely tune
this active antenna using a varactor? The remote unit uses a 40673
dual gate mosfet followed by a 2N5109 npn vhf/uhf transistor which
feeds a 30 turn bifilar wound 4:1 balun. Then rg58 to the control
unit. The whip is 58"/1473mm in length. Any thoughts on this?
Yes. People have done this to design a tunable antenna so you can do a
Google search on it. The antenna element of the right type is inductive
and the varactor diode capacitance across it can be used to resonate it
at some frequency.
--
Telamon
Ventura, California
A short whip will not be inductive at frequencies below 150 MHz or so. At HF
they are entirely capacitive probes.
Dale W4OP
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