----- Original Message -----
Sent: Monday, February 13, 2017 1:34
Subject: Re: [CrossCountryWireless]
Comparing CCW receive-only antennas
I often get asked which active antenna is best and my usual answer is "It
depends on what you want it to do".
Running through the antennas:
Broadband Active Antenna: This antenna was designed for airband monitors
who want a single antenna to cover VHF airband, military UHF airband and ADS-B
aircraft beacons. It also works on HF as an electric field antenna so that HF
signals from transatlantic aircraft can be heard. If you can mount this high
and in the clear away from any electrical wiring it works well over a wide
range of frequencies. Don't expect wonders if it's just propped up against a
wall downstairs. Coax fed with DC power fed up the coax cable.
HF Active Antenna: This antenna was designed for the RSGB noise measurement
project. It's designed to minimise noise pickup from the power supply or
feeder cable. Again if you can mount this high and in the clear it gives great
results on HF. If used indoors it can pick up a lot of RF noise by capacitive
coupling to the electrical wiring. Depending on the version it may be useful
for VHF FM reception. The "New York" version has a 70 MHz low pass filter to
reduce overload from megawatt EIRP FM transmitters on very high buildings.
Uses ethernet cable as RF feeder and DC supply.
HF Active Vee Antenna: The same amplifier as the HF Active Antenna with
double length whip elements in a vee configuration for HF use. Excellent for
HF NVIS, ground wave and general HF listening. Again best mounted in the clear
outdoors. Not recommended for indoor use. Uses ethernet cable as RF feeder and
HF Active Loop Antenna: Probably our best HF antenna. Surprisingly good
indoors at low level as there is no capacitive coupling to nearby electrical
wiring. Excellent for all HF listening as a low noise receiving antenna. We
have sold many to contest groups and professional HF listening stations as a
remote antenna for use while transmitting on the same site. It was originally
designed for use as a low noise HF antenna mounted above a HF transmitting
antenna. If mounted high and in the clear DX performance is excellent. RF
overload protection on this as well as the other antennas is excellent. Some
performance on VHF up to the 2m band but the antenna pattern isn't good on
VHF. Uses ethernet cable as RF feeder and DC supply.