Re: Comparing CCW receive-only antennas


David Cutter
 


Thanks, Chris, that's a great summary.  Sounds like the HFALA is the best for us.  However, how would the HF active antenna work if the loop antenna from the HFALA were attached?  Come to that, any "small" loop? 
 
David
G3UNA

----- Original Message -----
Sent: Monday, February 13, 2017 1:34 PM
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 DC supply.

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.

Regards,

Chris


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