[Lowfer] Beverages on LF?

[jrusgrove at comcast.net]

Scott

Unfortunately, not very well on 137 kHz.

Last season I installed a 1000' terminated BOG (beverage on ground) for 500 kHz reception. A BOG 
acts like an elevated beverage about twice it's length so it's in effect a 1 wavelength antenna at 
500 kHz. The antenna is built from RG-59 (which is used to return the signal from the far end) and 
provides both directions simulateneously. The good news is that it exhibits >20 dB F/B on 500 kHz. 
The bad news is it has little directivity at 137 kHz ... beverages need to be a wavelength (or more) 
to exhibit the desired directivity. Info on this beverage is available at

http://www.w1vd.com/500kHzBOG.pdf .

The large K9AY that I've been using for a number of years maintains good directivity (characteristic 
of a terminated loop) from about 700 kHz all the way down to bottom limit of the antenna - about 5 
or 6 kHz (limited by the transformers and preamplifier in use) . In excess of 20 dB F/B is available 
across the range. Info on this version of the K9AY can be found at

http://www.w1vd.com/K9AYLF.pdf .

The downside to the K9AY is that it has a cardiod pattern ... which isn't as desireable as the 
sharper pattern of a beverage. The obvious problem is that at 137 kHz a BOG would have to be about 
3600'!

Jay





----- Original Message ----- 
From: "Scott Tilley" <sthed475 at telus.net>
To: "Discussion of the Lowfer (US, European, &amp;UK) and MedFer bands" <lowfer at mailman.qth.net>
Sent: Sunday, September 12, 2010 2:26 PM
Subject: [Lowfer] Beverages on LF?


>  Hi Guys
>
> I'm looking for opinions on how a 500-1000' beverage would work on
> 137KHz?  Assume the antenna was optimized for 160m operation.
>
> How would it behave on 137KHz compared to a resonant loop or another RX
> antenna specifically designed for the purpose?
>
> TU
> Scott
> VE7TIL
>
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