Re: Topband: Beverage Antenna Tuning

["Ashraf Chaabane" <ash.kf5eyy@gmail.com>]

Hi Mark, Peter,

The BC station to be used to minimize the back lobe would be in Egypt or 
Saoudi Arabia right on the back of my beverage antenna. That should 
offer signals coming well above 10deg (I presume!). Comment noted 
regarding how efficient that will be on 1820 kHz. I know Egypt has BC 
station on Medium Wave which isn't that far from 160m.
Frank,

I have two 3-feets rods at each end so far with two buried radials at 
the feed end. I will add radials at the termination side as well as you 
recommend.
For the sake of experimentation, I  will play a bit with the termination 
resistor trying to flatten the SWR curve as much as possible, although, 
as many said, I shouldn't expect a noticeable improvement in reception.
Thank you all and those who wrote me in private. This generous technical 
support is needed for developing experience on 160 among 3V hams (mostly 
youngsters). I hope we will be ready with strong 100W signals this 
winter!
73 from Tunisia

Ash 3V8SS/KF5EYY
www.kf5eyy.info



------ Original Message ------
From: donovanf@starpower.net
To: topband@contesting.com
Cc: "Ashraf Chaabane" <ash.kf5eyy@gmail.com>
Sent: 04/07/2018 19:00:33
Subject: Re: Topband: Beverage Antenna Tuning

> Hello Ash,
>
> Your results are normal for a typical Beverage. Receiving performance
> is not significantly degraded by imperfect matching of the coaxial 
> feedline
> to the Beverage feed point or by non-optimum termination resistance.
> You could optimize your matching transformer and termination resistor
> but the improvement in receiving performance will be very minor.
>
> On the other hand, Beverage antenna receiving performance can be
> significantly degraded by:
>     - nearby antennas, power lines and other long conductors, and
>     - common mode signals coupled into the feedline
>
> You could optimize your matching transformer to reduce the VSWR to
> closer to 1:1 on the frequencies you care about most, but you won't
> notice any improvement in receiving performance.
>
> You could optimize your Beverage termination by:
>    - adding extra ground rods and/or short radials to improve ground 
> resistance
>       stability at the connection to termination resistor.
>    - adjusting the termination resistance to minimize the VSWR 
> excursion
>       as you sweep from 1.5 to about 10 MHz
>
> 73
> Frank
> W3LPL
>
> --------------------------------------------------------------------------------
> From: "Ashraf Chaabane" <ash.kf5eyy@gmail.com>
> To: topband@contesting.com
> Sent: Wednesday, July 4, 2018 2:13:27 PM
> Subject: Topband: Beverage Antenna Tuning
>
> Hi All
>
> I measured the SWR in my beverage antenna; the SWR fluctuates between 
> 1.5
> and 3 in a range of 1.8 to 7 MHz. (See:
> https://drive.google.com/drive/folders/0B9AtNpPfAOUMRDNsaXROMG1VUTg?usp=sharing
> )
> I know SWR should not vary too much. However, some people are 
> suggesting
> adjusting the termination resistor. Others suggest checking the 
> transformer
> number of windings for a good match. What shall I do?
>
> 73 Ash 3V8SS/KF5EYY
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