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Re: [CQ-Contest] to pre-amp or not to pre-amp

To: cq-contest@contesting.com
Subject: Re: [CQ-Contest] to pre-amp or not to pre-amp
From: Jim Brown <k9yc@audiosystemsgroup.com>
Reply-to: k9yc@arrl.net
Date: Sat, 16 Jan 2016 22:50:31 -0800
List-post: <cq-contest@contesting.com">mailto:cq-contest@contesting.com>
On Sat,1/16/2016 10:30 AM, Franki ON5ZO wrote:
Question 1 is: would I benefit from a pre-amp right at the feedpoint of such a flag or single K9AY loop antenna? Coax to the shack is about 50-60m max.

This fundamental rule works for ANY antenna. Connect it to your radio. If the noise level from the antenna is at least 10 dB higher than the noise level with no antenna and a 50 ohm resistor at the antenna input, you don't need a preamp. Do this test under the quietest actual conditions -- if on 160, between an hour before sunset and an hour after sunset, on a day when static is low.

Question 2 is: The copper wire 'wannabee beverage' runs 10-15 cm above the conductive wire mesh fencing (1m to 1.20m high). Would it be better to just put it on the ground as a BOG? What about a pre-amp there?

It's generally accepted that Beverages do NOT perform well in proximity to other parallel conductors (like your fence). Beverages work because of their interaction with poorly conducting earth, and other parallel conductors defeat that.

73, Jim K9YC
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