[HCDX]: Re: K9AY antenna

["Al - K 4 G L U" <merriman@xxxxxxxxxxxxxxxxxx>]

-----Original Message-----
From: Patrick Martin <mwdxer@xxxxxxxxx>
To: merriman@xxxxxxxxxxxxxxxxxx <merriman@xxxxxxxxxxxxxxxxxx>
Date: Sunday, July 11, 1999 7:07 AM
Subject: K9AY antenna


Hi:

I am thinking about building a K9AY antenna. I do have several
questions.
Do they work as well as an EWE antenna?
Are they as directional?


Beyond reading two articles about these in QST and a bit of hearsay
concerning their performance I have no experience with these antennas.  In
what I've written I've stated several times that F/B nulls approaching 40db
are common with the K9AY's - does the EWE do this well?  One thing that I've
heard several times about the EWE is that their performance is affected by
slight changes in ground conductivity such as during rain, etc.  If this is
true - and I don't know that it is - this is one area where the two systems
are radically different as the K9AY's require very little in the way of a
ground and are not affected in the least by rain, etc - at least as far as
I've been able to tell in a year of use.
To get max performance from the EWE I'm sure you would need a remotely tuned
variable termination which should be fairly easy to implement using the
twisted pair wire for the antennas like Steve Byan uses with his beverages.

When building one, Do you point the antenna in the direction you want to
receive, or is the input pointed in the direction you want to receive?


Main pickup by the K9AY's is from the feedline end towards the terminated
end - just the opposite of a terminated beverage.

   My EWE is directional off the input. Since it runs to the NE, it is
directional from the SW. I also have a pot at the end to adjust as the
swamp's water table changes alot, especially in the Winter months.
   Do you have a length that works the best for MW?


Per the original article antenna length should be "not much more than 1/4
wavelength at the highest frequency of interest".  This means that antennas
up to 150 feet in length - and maybe just a bit more should give full LW/MW
coverage including the X-band as a full wavelength at 1700 kHz is almost 600
feet.  My loops are 90 feet in length and with a 15db preamp give signal
levels comparable to my slopers that are approximately 60 feet high at the
high end and 150 long.

73/DX

Al - K 4 G L U
Chincoteague Island, VA
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