[Lowfer] Really big coils- VA3LK

Paul A. Cianciolo paulc@snet.net
Tue, 1 Aug 2000 21:49:46 -0400


Hello Larry and the group,

Thanks for the information on the coils length/dia/conductor dia.
Very interesting.

Well there is a RTTY station just down the band from you which 3/4 scale
here with the noise
at 1/10 scale...   I know not very scientific

When tuned to 136.960 I can see the 2 tones very clearly ...   I may fire up
gram later and see
how far out of the noise they are.  Using 800 Hz BFO offset the tone are 800
Hz and 725Hz

I am not sure if this is The NPG station you are talking about or not.  It
is very strong!
It is nearing 0200 UTC so I am off to the listening post.   By the way I am
using a  preamp witha tuned front end on the
200' wire

I will have to lay a wire across the lawn and try my loop out in the woods.
It is about 300'
awayu from anything and is usually pretty quiet

I would appreiciate any info on NPG...   could I decode it somehow and know
for sure?

Thnaks again Larry



Paulc
W1VLF

Cloudbounce Webpage  http://www.qsl.net/w1vlf/
Rescue Electronic Surplus http://www.rescueelectronics.com

1982 Vanagon Diesel  Turbo Diesel 1.9
GE Electrak E20 and E15  electric tractors
First place in local tractor pulls  at 1750 LBS
With Stock E-20 Electric tractor
----- Original Message -----
From: Larry Kayser <kayser@sympatico.ca>
To: Paul A. Cianciolo <paulc@snet.net>; <lowfer@qth.net>; AMRAD Tacos
<tacos@amrad.org>
Sent: Tuesday, August 01, 2000 11:01 AM
Subject: Re: [Lowfer] Really big coils- VA3LK


> Paul es group.....
>
> >I wonder if anyone has tried building a really big coil out of CATV line.
> >I can easily be formed into 3 or 4 foot dia circles and even more. With
the
> >right lenght to
> >dia. ratio yield a very hi Q coil.  The cable diameter .5" to 1.125" and
is
> >relatively light.
> >
> >Might be OK for base loading.  Any ideas on this crazy scheme.
>
>
> I have tried using some black jacket aluminum shield coax here at the 4 ft
> diameter and I was not able to in the few hours I had to work on it make
the
> coil perform.  I unrolled the coax and used it as a radial were it made a
> measureable contribution.  IF I have the sense right very high performance
> coils, Hi Q included are when the coil approaches square, diameter by
> length.  The Q seems to improve quickly when one goes to an odd number of
> vertical winding posts and creates what I think is called the basket
weave.
> My next series of loading coils here will be LITZ wire on a basket weave
in
> a square format with a small variometer at the top for screwdriver motor
> tuning under PC control.
>
> >Also has anyone heard VA3LK on 137.710.   I am very dissapointed that I
> >cannot hear/see him using
> >Spectran 4.0 and a 200 foot long wire.  I heard that there was a good
> signal
> >in Western PA and also that someone
> >1100 miles away recently copied him  I gotta be doing something wrong.
> >137.710 correct with 800 Hz  CW note?
> >Also no sign of his friend 14 Hz down.
>
>
> There are a number of issues for this, not sure of all of them but a 200
ft
> long wire is from my experience here a lousy LF receiving antenna.  My
best
> results last winter were with a 1000, 2000, and 4000 ft Beverages laying
on
> the ground, terminated in about 500 ohms and using copper pipes bashed
into
> the ground - which is really horizontal under the soil and above the rock
> hi.  I have an email from a chap in Maine who copies the test signal on
his
> speaker most of the time, his antenna is very significant, ie big.  From
my
> meager experience it is essential to go through a very hard learning curve
> with this LF receiving bit, hearing weak signals is a complete layer of
> significant effort under the general listening on LF.
>
> I offer this hint.  I have a large coil and capacitor that is series
> connected on any broadband antenna to resonate on 137 kHz.  This assembly
> makes and amazing difference for weak signal reception.
>
> The last point was that I have learned that the use of the DSP programs
Gram
> etc. need to be diddled a lot to get the last few dB out of them.  When I
> was looking for WA2XTF (AMRAD beacons in the Washington area) I spent
months
> seeing a faint line that I came to know was them, the second signal 5 Hz
> away was similarly there but not readable (and it never has been readable
> here).  One after noon I looked up and there on the screen was the
complete
> call sign.  The point of this comment is that I was near the threshold for
a
> long time before I managed to pull them out of the mud.  My total of heard
> reports for the test transmissions from here on 137.710 is now over 20, I
> know this as I am making up the SWL/QSL cards for those who have been kind
> enough to send in reports.  I know that if you are not able to hear the
NPG
> rtty on 135.95 at times that you will not hear me.  If you need the full
> data on NPG let me know I will get my log book and send you a summary of
> information on that signal.
>
> The VA3LK test signal on 137.710 continues at this time transmitting EVEN
> hours UTC with .4 wpm CW.  If you are having trouble identifying the
signal
> I can send you a .jpg of what others are seeing so you can have a sense of
> finding the signal in the noise.
>
> 73
>
> Larry
> VA3LK
>
>
>
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