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Re: [TenTec] How to Hear the Weak Ones,

To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Subject: Re: [TenTec] How to Hear the Weak Ones,
From: Robert & Linda McGraw K4TAX <RMcGraw@Blomand.Net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Thu, 17 Nov 2005 20:56:20 -0600
List-post: <mailto:tentec@contesting.com>
In reading through all of this it does appear that the antenna is the most upfront part of the station. Certainly there are specific antenna designs and configurations that lend themselves to enhanced RX application. While at the same time there are some the lend themselves to TX application or in some cases both RX/TX applications. As to the receiver, I agree that today's modern receivers for the most part are very adequate technically in normal operation. For multi station contesting or just contesting alone, certain features are most desirable.

One point that seems to always get overlooked and seems to be most mis-understood is the issue of noise as received and presented by the receiver. Time and time again I hear comments on the air to the effect the "I have a S-9 noise level today". Well sir, if you have a S-9 noise level the first thing you need to do is reduce the RF gain or add some attenuation on the input. Regardless of your outside noise level, allowing the receiver AGC to pump up to an S-9 is simply sucking up good dynamic range that you will need to hear the weak ones in the presence of strong signals. Don't get the idea that "more gain" will allow you to hear the weak ones, specially if you are amplifing random or unwanted noise. Simply not a fact of physics. I make it a practice to adjust the RF gain or attenuation so the S meter indicates no more than S-2 to S-3 on non-signal conditons. You will be surprised how efficient the receiver will be and how much less fatugue will be experienced by the operator under these conditions. And those weak signals will appear to "pop out of the noise".

The human ear is the most efficient filter system today. Typically it can detect signals that are as much as 10 dB below the noise threshold or thus signals down in the noise. This is where good confortable headphones come in to play complemented with an operating position that is not contaminated with acoustic noise. Nothing like a 600 CFM blower on the amp screaming in your ears augmented by the TV in the next room. Who needs this.

Finally, there's several good external DSP boxes on the market that do wonders for assisting in separating noise from signal. Get one and try it, you might find you like it.

73
Bob, K4TAX


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