Message-ID: <A40173A4BD7E40F5BC13D77CC7EC78C2@gnat>
From: "Alan Melia" <alan.melia@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
References: <CADxXMjd0qdcV0+BiGFszX2yRg_ihBGqx8MRZ-0JP_v007KykbA@mail.gmail.com>
Date: Mon, 1 Jun 2015 12:00:04 +0100
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Subject: LF: Re: Top loaded vertical spiral antenne
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Hi Marcel the original idea came from a Pat Hawker Technical Topics =
column. It was originally in a Canadian BC Journal and recommended for =
short free standing MW BC antennas. We  did the experiments you found in =
the web pages on 136kHz. Gary up in Preston made one too. The problem =
with them is the windage of the spiral, Garry G4WGT had his destroyed in =
a light gale.  They can work but as our experiments showed top-load =
capaitance is far more effectinf at reducing ground loss and increasing =
the efficiency. Hence the additional tests with capacitance added above =
the spiral. wirespacing was 5 to 10 cm from memory and not too critical, =
yes it you need the inductance you can wing out below the stays and back =
in again above then and get 4 times the inductance. You will not need so =
much inductance at 475kHz. It is also possible to helically wind the =
vertical. The gain achieved is relatively low measured at an increase in =
Rrad of about 10%.

Best Wishes
Alan
G3NYK
  ----- Original Message -----=20
  From: Marcel Bos=20
  To: rsgb_lf_group@blacksheep.org=20
  Sent: Monday, June 01, 2015 10:11 AM
  Subject: LF: Top loaded vertical spiral antenne


  Members,


  My backyard is in the city 8 x 8 m.  My intention is to do some =
experiments on 472 khz.

  Ready: RX converter 0-500 khz 10 mhz osc. and K3, RX ant. pa0rdt whip =
and receiving loop


  TX: GW3UEP 100 watt, RF meter, and variometer 30 uh -600 uh


  Now i'm looking for a antenne. Found a article from Finnbar EI0CF and =
Alan G3NYK about the spiral toploaded vertical.


  Has any body tryed this antenne, is the original article availble.

  What is the distance between the wire's  of the spiral?

  Also talking about a double spiral?


  So who is gone help me out  ore has some better suggetions for a =
antenne in my backyard

  http://www.xeropage.co.uk/g3nyk/spiraltop.htm#aerials


  tnx in advanced=20


  Marcel

  PA9M


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<BODY bgColor=3D#ffffff>
<DIV><FONT size=3D2 face=3DArial>Hi Marcel the original idea came from a =
Pat Hawker=20
Technical Topics column. It was originally in a Canadian BC Journal and=20
recommended for short free standing MW BC antennas. We&nbsp; did the =
experiments=20
you found in the web pages on 136kHz. Gary up in Preston made one too. =
The=20
problem with them is the windage of the spiral, Garry G4WGT&nbsp;had his =

destroyed in a light gale.&nbsp; They can work but as our experiments =
showed=20
top-load capaitance is far more effectinf at reducing ground loss and =
increasing=20
the efficiency. Hence the additional tests with capacitance added above =
the=20
spiral. wirespacing was 5 to 10 cm from memory and not too critical, yes =
it you=20
need the inductance you can wing out below the stays and back in again =
above=20
then and get 4 times the inductance. You will not need so much =
inductance at=20
475kHz. It is also possible to helically wind the vertical. The gain =
achieved is=20
relatively low measured at an increase in Rrad of about =
10%.</FONT></DIV>
<DIV><FONT size=3D2 face=3DArial></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2 face=3DArial>Best Wishes</FONT></DIV>
<DIV><FONT size=3D2 face=3DArial>Alan</FONT></DIV>
<DIV><FONT size=3D2 face=3DArial>G3NYK</FONT></DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; =
PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px"=20
dir=3Dltr>
  <DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
  <DIV=20
  style=3D"FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: =
black"><B>From:</B>=20
  <A title=3Dpa9marcel@gmail.com =
href=3D"mailto:pa9marcel@gmail.com">Marcel Bos</A>=20
  </DIV>
  <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Drsgb_lf_group@blacksheep.org=20
  =
href=3D"mailto:rsgb_lf_group@blacksheep.org">rsgb_lf_group@blacksheep.org=
</A>=20
  </DIV>
  <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Monday, June 01, 2015 =
10:11=20
AM</DIV>
  <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> LF: Top loaded =
vertical spiral=20
  antenne</DIV>
  <DIV><BR></DIV>
  <DIV dir=3Dltr>
  <DIV>
  <DIV>
  <DIV>
  <DIV>
  <DIV>
  <DIV>
  <DIV>
  <DIV>
  <DIV>
  <DIV>
  <DIV>Members,<BR><BR></DIV>My backyard is in the city 8 x 8 m.&nbsp; =
My=20
  intention is to do some experiments on 472 khz.<BR></DIV>Ready: RX =
converter=20
  0-500 khz 10 mhz osc. and K3, RX ant. pa0rdt whip and receiving=20
  loop<BR><BR></DIV>TX: GW3UEP 100 watt, RF meter, and variometer 30 uh =
-600=20
  uh<BR><BR></DIV>Now i'm looking for a antenne. Found a article from =
Finnbar=20
  EI0CF and Alan G3NYK about the spiral toploaded =
vertical.<BR><BR></DIV>Has any=20
  body tryed this antenne, is the original article =
availble.<BR></DIV>What is=20
  the distance between the wire's&nbsp; of the spiral?<BR></DIV>Also =
talking=20
  about a double spiral?<BR><BR></DIV>So who is gone help me out&nbsp; =
ore has=20
  some better suggetions for a antenne in my backyard<BR><BR><A=20
  =
href=3D"http://www.xeropage.co.uk/g3nyk/spiraltop.htm#aerials">http://www=
.xeropage.co.uk/g3nyk/spiraltop.htm#aerials</A><BR><BR></DIV>tnx=20
  in advanced <BR><BR></DIV>Marcel<BR></DIV>PA9M<BR>
  <DIV>
  <DIV><BR></DIV></DIV></DIV></BLOCKQUOTE></BODY></HTML>

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