[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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