Re: Topband: Beverage F/B using oscillator

2018-10-15 Thread Ashraf Chaabane 

Greg,

I re-did the exercise at 470m distance from both ends of the beverage 
and the F/B has increased to 7db. I was tired to go further in a VERY 
muddy ground but I will test again at near-field edge (around 840m) when 
it gets drier.


Thanks

73 Ash 3V8SF
www.kf5eyy.info

Message: 2
Date: Tue, 9 Oct 2018 22:57:54 +1300
From: Greg - ZL3IX 
To: topband@contesting.com
Subject: Re: Topband: Beverage F/B using oscillator
Message-ID: 
Content-Type: text/plain; charset=utf-8; format=flowed

Hi Ashraf,

The rule of thumb I use is 2D^2 /lambda, where D is the largest
dimension of the antenna. So if your Bev is 320m long you need to be
over a km away. If only 160m long you need to be 300 m away.

73, and I hope to work you one of these days at my SR.

Greg, ZL3IX
_
Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: Beverage F/B using oscillator

2018-10-10 Thread Jose Orellana - EA7BJ 
Hi, Rash.
You can look in the links that I put.
IV3PRK explains how to adjust (gain and F/B) in a BOG and an RBOG.
These explanations were very useful for me to improve my RX antennas.
Hope this can help you.

http://www.iv3prk.it/hc1pf-bog-2.htm

http://www.iv3prk.it/new-page.htm

73 EA7BJ, Jose.



IV3PRK Pierluigi "Luis" Mansutti (ex HC1PF)<http://www.iv3prk.it/new-page.htm>
The Reversible BOGs at HC1PF At last achieved my best solution with receiving 
antennas . After trying every kind of receiving antenna I came to the 
conclusion that the only one functioning in my environment was a Beverage on 
ground, outside of my wall and electric fence and far from the power lines but, 
after a few days of happiness, a bulldozer entered in that terrain and….no more 
BOGs.
www.iv3prk.it


[http://www.iv3prk.it/user/image/hc1pf-bog-2_archivos-image002.jpg]<http://www.iv3prk.it/hc1pf-bog-2.htm>

IV3PRK Pierluigi "Luis" Mansutti (ex 
HC1PF)<http://www.iv3prk.it/hc1pf-bog-2.htm>
The BOG’s at HC1PF. Finally getting them to work, and definitely the best, but 
what a sad epilogue! So, after the disappointing experiment with the horizontal 
loop, I decided to get out of my wall and try a Beverage on ground.
www.iv3prk.it




Enviado desde Outlook<http://aka.ms/weboutlook>


De: Topband  en nombre de Ashraf Chaabane 

Enviado: martes, 9 de octubre de 2018 10:07
Para: topband@contesting.com
Asunto: Topband: Beverage F/B using oscillator

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
<http://www.kf5eyy.info/>Topband: *http://www.kf5eyy.info/topband.htm
<http://www.kf5eyy.info/topband.htm>*
Phone/SMS/Whatsapp: (+216) 22670026
Skype: kf5eyy
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Re: Topband: Beverage F/B using oscillator

2018-10-09 Thread Edward Sawyer 
As a point of reference - I have 4 terminated beverages from 200 - 350m long
(also 2 unterminated bererages).  I use them on 40 - 160M.  I typically see
10 - 25dB of front to back on these beverages.  On 40M and 80M, while
contesting, if I am not careful to first listen on the transmit antenna
before CQing, I can be on top of a US station that I can't hear because of
using the EU terminated beverage.

 

4db does not seem like a good result for a terminated beverage.

 

I can't speak to BOGs as I have not used them.

 

73

 

Ed  N1UR

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Re: Topband: Beverage F/B using oscillator

2018-10-09 Thread F Z_Bruce 


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.kf5...@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
_
Topband Reflector Archives - http://www.contesting.com/_topband
_
Topband Reflector Archives - http://www.contesting.com/_topband

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Re: Topband: Beverage F/B using oscillator

2018-10-09 Thread pa5mw 
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.kf5...@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
_
Topband Reflector Archives - http://www.contesting.com/_topband
_
Topband Reflector Archives - http://www.contesting.com/_topband

_
Topband Reflector Archives - http://www.contesting.com/_topband

Topband: Beverage F/B using oscillator

2018-10-09 Thread F Z_Bruce 


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
_
Topband Reflector Archives - http://www.contesting.com/_topband
_
Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: Beverage F/B using oscillator

2018-10-09 Thread Greg - ZL3IX 

Hi Ashraf,

The rule of thumb I use is 2D^2 /lambda, where D is the largest 
dimension of the antenna. So if your Bev is 320m long you need to be 
over a km away. If only 160m long you need to be 300 m away.


73, and I hope to work you one of these days at my SR.

Greg, ZL3IX

On 2018-10-09 09:07 p.m., 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!


_
Topband Reflector Archives - http://www.contesting.com/_topband

Topband: Beverage F/B using oscillator

2018-10-09 Thread Ashraf Chaabane 
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
_
Topband Reflector Archives - http://www.contesting.com/_topband