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Re: Topband: Beverage F/B using oscillator

To: pa5mw@home.nl, Topband <topband@contesting.com>
Subject: Re: Topband: Beverage F/B using oscillator
From: F Z_Bruce <k1fz@myfairpoint.net>
Reply-to: k1fz@myfairpoint.net
Date: Tue, 09 Oct 2018 10:31:37 -0400
List-post: <mailto:topband@contesting.com>
With the BOG  it is not very variable/ if any..(it does vary with conductivity 
of the soil) (consider sand as non-conductive)  

The Beverage can be tilted somewhat, however its not" one size fits all".  Low 
angle signal signals are not affected, high angles somewhat. (end height affect 
end impedance) 
 At one location  very low angle neighborhood noise may be worse.
Decide what you want and computer  model it 

73
Bruce-k1fz
 


On Tue, 9 Oct 2018 15:34:15 +0200,  wrote:

Additional question; 
with respect to the BOG/Beverage backlobe upwards angle, does the
test-generator antenna need to be lifted from local groundlevel by say 2-
10m?

Or can this test be done just as reliable on groundlevel?


73
Mark, PA5MW



-----Original Message-----
From: Topband  On Behalf Of F Z_Bruce
Sent: Tuesday, October 09, 2018 3:01 PM
To: ash.kf5eyy@gmail.com; Topband 
Subject: Topband: Beverage F/B using oscillator


Good information.
Finding the best BOG F/B.
I use an model  MFJ-5014  white noise generator off the 'back' of the BOG
antenna.  Then tune the receiver to find the 'minimum noise' signal
frequency.    Adjust the BOG antenna length to bring it into 160 meters..
Care must be taken not to create a neighborhood  noise problem.   

73
Bruce-k1fz




On Tue, 9 Oct 2018 09:07:42 +0100, Ashraf Chaabane  wrote:

Hi All,

I used a 1.843 oscillator to check NA beverage F/B. The mesurements were
taken 160m away from each end of the antenna. Noise level was constant. I
had 4 dB difference between front and back signals.

Is that what I should expect? Is 1 wavelength distance enough to do this
experience?
This will be repeated with different terminations and I want to make sure
I'm doing it correctly. It will also be applied on the newly installed BOG
to determine optimum length.

Tnx and see you on the air!
--
Ash ~ 3V8SF
Topband: *http://www.kf5eyy.info/topband.htm
*
Phone/SMS/Whatsapp: (+216) 22670026
Skype: kf5eyy
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