Re: LF: Testing WSPR2 to night a short antenna for future mobile use on MF band.

["Graham" <g8fzk@g8fzk.fsnet.co.uk>]

I think so  Bob , you  would have a  parallel tuned cct  , with  high Z , a open cct  between  the  rod and the  top load ?

 

I use a  series coil  , part of the  inv L at the  top of  the  vertical section 

 

G,

From: Bob Raide

Sent: Wednesday, June 11, 2014 8:30 PM

To: rsgb_lf_group@blacksheep.org

Subject: RE: LF: Testing WSPR2 to night a short antenna for future mobile use on MF band.

Warren;
I never gave a thought to self resonating a coil arrangement.  It could resonate but put out no power to the ant if self resonant?
 

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Date: Wed, 11 Jun 2014 14:48:26 -0400
From: wd2xgj@gmail.com
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Testing WSPR2 to night a short antenna for future mobile use on MF band.

Andy,

   You need such a large inductance for this, be careful how you wind the coil since self–resonance might be near the operating frequency!

73 Warren K2ORS

On Tuesday, June 10, 2014, André Guyé <andre.guye1@aliceadsl.fr> wrote:

Hi to all.

 

I am thinking now about the design of a short vertical antenna, for MF mobile use in next winter season.

 

To night I’ll test this first configuration : a 2 meters high tube (2 cm of diameter) and a top hat (wheel shape) 80 cm of diameter. It needs about 2.4 mH base coil tuning. The TX is 3 Watts output. Base voltage is 2,2 kV RMS.

 

I’ll test this small antenna to night, beginning at 2000 TU on WSPR2 MF band. The expected ERP is about 1 mW.

 

All reports be welcome. Note that to night the testing antenna has his base on the garden with a ground earth rod, so it is not installing on my car.

 

73 de Andy. F6CNI - JN19QB

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73 Warren K2ORS
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