Hi Felipe,
I've never done Beverage switching in my antenna field, my
nine receiving antenna feedlines go individually to my shack.
But I'll speculate a bit, perhaps others can comment based on
their actual experience.
The feed point impedance of a Beverage antenna is approximately
450 ohms. If you use relays to select among the Beverages at
the 450 ohm impedacne level you probably will have great
difficulty achieving adequate isolation.
You're more likely to achieve good switching isolation on the low
impedance side of your Beverage matching transformers. If you
must use a common ground rod for multiple Beverage feed points,
you should also switch the connections to the ground rod.
73
Frank
W3LPL
----- Original Message -----
From: "Filipe Lopes" <ct1ilt@gmail.com>
To: "Frank Donovan" <donovanf@starpower.net>
Cc: "topband" <topband@contesting.com>
Sent: Sunday, March 27, 2016 9:53:21 PM
Subject: Re: Topband: : Re: 1 center point to ground all 8 beverages??
Hello Frank
Thank you for your email, just one more question.
Do you put the relay directly at each antenna wire or do you just connect the
ground to a common point and you select and deselect the antenna you want to be
connected to ground?
73s Filipe CT1ILT
Sent from my Huawei Mate 8
Em 22/03/2016 4:12 p.m., < donovanf@starpower.net > escreveu:
Hi Felipe,
As W4ZV noted in his posting, three meter ground rod spacing was
not enough when he brought multiple Beverages to a common point.
A much better solution is to use inexpensive hermetically sealed
relays to connect only the selected Beverage to a single ground rod.
73
Frank
W3LPL
From: "Filipe Lopes" < ct1ilt@gmail.com >
To: "k1fz" < k1fz@myfairpoint.net >, "topband" < topband@contesting.com >
Sent: Tuesday, March 22, 2016 1:17:51 PM
Subject: Re: Topband: : Re: 1 center point to ground all 8 beverages??
what about 7 ground rods 20cm apart, will it do ?
73's Filipe Lopes
CT1ILT - CR6K
F4VPX - TM3M
2016-03-22 14:09 GMT+01:00 K1FZ-Bruce < k1fz@myfairpoint.net >:
>
> ----- Forwarded message from K1FZ-Bruce -----
>
> Date: Tue, 22 Mar 2016 09:04:06 -0400
> From: K1FZ-Bruce
> Reply-To: k1fz@myfairpoint.net
> Subject: Topband: Fwd: Re: 1 center point to ground all 8 beverages??
> To: Topband
>
> I agree. We have been thinking of switching at the coax cable location.
> Will need to correct my Beverage notes page.
>
> The W4ZV and W3LPL method will work.
>
> 73
> Bruce-K1FZ
>
> www.qsl.net/k1fzbeverage_antenna.html
>
> http://www , qsl.net/k1fz/beverage_antenna.html
>
>
> ----- Forwarded message from Bill Tippett -----
>
> Date: Tue, 22 Mar 2016 05:19:48 -0400
> From: Bill Tippett
> Reply-To: Bill Tippett
> Subject: Re: Topband: 1 center point to ground all 8 beverages??
> To: topband
>
> W3LPL:
>
> >Another solution is to use
> relays to connect only the selected Beverage to the ground rod
> and disconnect the other seven.
>
> I've done this for 31 years from 3 different locations with no problems.
> From a 2011 post on this subject:
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>
> ----- End forwarded message -----
>
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
|