[KYHAM] Advice About HF

[n4lq]

I have to bite my tongue when someone recommends the BW antenna. Never 
has there been a more inefficient and overpriced "antenna". Basically 
it's just a resistor at the end of a feedline. Radiations happens due to 
wide spacing of the feedline. I bought one in 1995 just to compare 
against a G5RV. The BW was 20db down on 80 meters! I managed to get a 
refund after the test. 
You might consider the modern version of the Windom or loop antennas. 
These are easy for internal antenna tuners to match and are fairly 
efficient. I use an 80 meter horizontal loop fed on the corner with a 
4:1 balun. My swr is 1:1 on all but the warc bands. WARC bands require 
the use of the rigs internal tuner, an easy match. This loop is a 
triangle and is fairly omnidirectional on all bands, having many lobes. 
Total cost, about $50 for balun, wire and pulleys.

Steve N4LQ

-----Original Message-----
From: Bill Fuqua <wlfuqu00 at uky.edu>
To: kyham at mailman.qth.net
Date: Mon, 06 Jun 2005 12:41:29 -0400
Subject: Re: [KYHAM] Advice About HF

> Before you get real serious about the B&W broadband dipole (T2FD) you
> may 
> want to look at an analysis of it.
> http://www.cebik.com/wire/t2fd.html
> 
> Note the losses in the load resistor at lower frequencies and at all
> other 
> frequencies.
> Generally, on the ham bands half of the power is lost in heating the 
> resistor, at best, except for 10 meters.
> Between most ham bands it is 3/4 lost or more. And at lower frequencies
> only 10th to 16th of the transmitter output is radiated.
> 
> This would not affect receive at all due to the high atmospheric
> background 
> noise floor. Which increases at lower frequencies. Apparent low noise 
> behavior is probably due to the antennas attenuation factors.
> 
> Now saying that, I will have to admit that it is easy to match and most
> people will not really notice the loss of 3/4 of radiated power and
> it's 
> impedance is not affected much by nearby objects and how it is strung 
> up.  Also, these losses would not be noticed at all on receive.  At all
> frequencies that it is designed for you are still atmospheric noise
> limited 
> on receive.
> 
> 73
> Bill wa4lav
> 
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