[Antennas] 160 Inverted L 160 Radials

[Igor Sokolov]

----- Original Message -----
From: "Dan Richardson" <k6mhe at arrl.net>
To: "W3OA" <w3oa at adelphia.net>; <antennas at mailman.qth.net>
Sent: Thursday, November 17, 2005 10:43 PM
Subject: Re: [Antennas] 160 Inverted L 160 Radials


At 04:41 PM 11/16/2005, you wrote:
>Did you get a chance to evaluate what the author said as opposed to how he
>said it?  What do you think?  Is it reasonably good for my first 160
antenna?

>Reading over KE4UYP's information there is several of his statements that
>are not correct. For example his statement that a vertical's efficiency is
>less than 50% for twenty-meters and above and less than 20% efficiency on
>forty-meters and below is nonsense. Brown, Lewis and Epstein's studies more
>than five-decades ago discredits that statement.

>He goes on to say the an adjoining mast can be metal on non-metallic as it
>"It really does not matter" then, later in his document, contradicts that
>statement stating different bandwidths for a metal tower vs. tree mounting
>for his antenna.

>In that I had a little time this morning to mess around I modeled his
>antenna using NEC4 (Although NEC2 give almost identical results) comparing
>his so called vertical with a standard ½-wave dipole and a ¼-wave vertical.
>I used KE4UYP's  recommended height for the eighty-meter version of his
>design (25-feet). This same height was used for a ½-wave dipole reference.
>For those who might be interested I've placed the total gain elevations
>plots on my web site and they can be view at:
>http://k6mhe.com/sub/KE4UYP_Vertical.gif

IMHO Danny is absolutely correct but still the original question was "Is it
reasonably good for my first 160 antenna?"
My answer to that would be "Yes". The problem is that 1/4 wl vertical
radiator on 160 m is not always possible.  It will not be antenna for DXing
but you will be able to work locals and some occasional DX. For 160M though
I would recommend aluminum mast 20m tall and some radials at the bottom.
Otherwise the efficiency of the antenna will be way too low.  BTW I am going
to be in CQWW CW contest operating from 8Q7DV over the weekend. We have 21 m
tall vertical with capacitive loading there set in salt water of Indian
Ocean. It works pretty well. Last time in March we have worked 30-40
different USA and hundreds of EU from there on 160 m and even much more on
80 m where the vertical is true 1/4 wave length.

73, Igor UA9CDC