Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

LF: Re: Loading Coils

To: [email protected]
Subject: LF: Re: Loading Coils
From: "Dave Brown" <[email protected]>
Date: Wed, 17 Nov 2004 23:30:50 +1300
References: <B333AB0EF6D4D4118BAF00508BAED8EA088D9ECA@mms12014.stv.uk.astrium.corp>
Reply-to: [email protected]
Sender: [email protected]
Chris

Most of your losses will normally be in your ground system - not the loading coil. Amateur LF vertical antenna systems of necessity have severely constrained (size/efficiency) ground systems. So contributions from any half-decent loading coil will be way down, compared to the ground system losses.

Dave, ZL3FJ

----- Original Message ----- From: "OSBORN, Chris" <[email protected]>
To: "LF Group (E-mail)" <[email protected]>
Sent: Wednesday, November 17, 2004 10:19 PM
Subject: LF: Loading Coils





Hello LF Group

Many thanks for all comments and advice - most interesting.

I drilled out the wooden dowels on the loading coil and replaced
them with lengths of 15 mm plastic water pipe.
I was unable to obtain plastic rod at short notice and my XYL
wouldn't let me have her knitting needles !
The pipe was not really rigid enough and bent slightly but was
sufficient to prove the experiment.
With this new arrangement I obtained my personal best Q of about
250..

Placing the new coil in the aerial circuit made a slight improvement
to the aerial current - from about 1.2 A to 1.5 A
I would have thought that as most of the losses were in the coil a
bigger current improvement would have been achieved.

I share my office with some young electronics engineers and was
surprised that they know very little about RF inductors or Q factor.
It must be a dying art !

My next improvement will be to raise the 'droopy' end of my aerial,
presently at a height of about 5 metres
Unfortunately two neighbours' telephone wires pass over my garden
where the mast was to be situated.
Any suggestions - should I go over the wires or keep well clear of
them and cut a length off the aerial ?
Presumably I can't get the phone company to move their wires !!

73 Chris G3XIZ

This email is for the intended addressee only.
If you have received it in error then you must not use, retain, disseminate or otherwise deal with it.
Please notify the sender by return email.
The views of the author may not necessarily constitute the views of EADS Astrium Limited. Nothing in this email shall bind EADS Astrium Limited in any contract or obligation.

EADS Astrium Limited, Registered in England and Wales No. 2449259
Registered Office: Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2AS, England




--
No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.289 / Virus Database: 265.3.1 - Release Date: 15/11/2004





--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.289 / Virus Database: 265.3.1 - Release Date: 15/11/2004



<Prev in Thread] Current Thread [Next in Thread>