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Path: utzoo!watmath!clyde!burl!ulysses!allegra!alice!danny
From: danny@alice.UUCP (Dan Kahn, K1DK)
Newsgroups: net.ham-radio
Subject: Re: Antenna Tuners on Receivers
Message-ID: <2996@alice.UUCP>
Date: Fri, 21-Sep-84 17:17:10 EDT
Article-I.D.: alice.2996
Posted: Fri Sep 21 17:17:10 1984
Date-Received: Tue, 25-Sep-84 21:35:52 EDT
References: <239@whuxl.UUCP>
Organization: AT&T Bell Laboratories, Murray Hill
Lines: 24

I've never seen much reason to use an antenna tuner on a rcvr on HF,
so I read with interest the articles on the net advocating the practice.
Two reasons have been given, neither of which I find convincing:

1. "It will increase your S meter reading by an S unit or two."
But in the great majority of cases on HF, if you are having trouble
copying a signal it is because it is weak WITH RESPECT TO an adjacent
signal or atmospheric or power-line noise, NOT because of ABSOLUTE
weakness.  Better antenna tuning increases signal AND interference/noise
alike.  (And if you're NOT having trouble copying the signal,
who cares about the extra S units?)

2. "The antenna tuner is another tuned circuit, hence more selectivity,
which should be helpful given all the QRM on 40 and 20 meters." (Approx
quote.)  But when people talk about the "QRM on 40 and 20" they are
talking about QRM on the SAME FREQ or within a couple of KHz of the
desired signal.  No antenna tuner is going to help with that.
(If you have a kilowatt xmtr a few hundred yards away, operating a
few hundred KHz away from the signal you're trying to copy, the
extra tuned ckt could help, but that is clearly a special case.)

					Dan Kahn, K1DK
					Bell Communications Research
					Murray Hill, NJ