[Lowfer] Alpha on a degaussing coil

[Andy - KU4XR]

Dex;

That is one whale whopper of a deguassing coil. I have one here that 
I plan to experiment with. It's no where near that size. It came from 
a 15" CRT monitor. It reads 19.1 MilliHenries, with 16.5 Ohms " R " .
One thing confusing me is the self capacitance reading; -61µF . That is
the first time I have saw a negative capacitance reading before. 
A little internet reading gathered some info stating that neg. cap. was
a way devised to increase the voltage in a coil, which I can see the
purpose in a degausing coil. I wonder, and do you have any thoughts on
how the neg. cap. would affect efforts to tune the coil to a certain
frequency ?? Without the Neg.Cap. considered, it will take .0085µF to
resonate at 12.490 KHz. Plus the 16.5 Ohms will be pretty lossy I 
suppose, thus the need for the audio amp.

On another subject; That is a beautiful view of your property. I have
always been a " woods " person. Ever since I was a kid, I love being in 
the woods. To me; there is nothing like the smell of the woods right
after an Autumn rain. The cool air, and wet leaves;;;;; Comes pretty
close to the smell of melting solder ! hi - hi .

Well 73 to OM, and have a wonderful day :::


Andy - KU4XR - EM75xr - Friendsville, TN. USA
LOWfer Beacon " XR " @ 185.29875 KHz ( QRSS-60 )
Coordinates:  N:  35º 43' 54" - W:  84º 3' 16"
http://www.myspace.com/beaconxr
http://webpages.charter.net/ku4xr/


--- On Sun, 2/28/10, Dexter McIntyre W4DEX <dmcintyre at att.net> wrote:

> From: Dexter McIntyre W4DEX <dmcintyre at att.net>
> Subject: Re: [Lowfer] Alpha on a degaussing coil
 To: "Discussion of the Lowfer (US, European, & UK) and MedFer bands" <lowfer at mailman.qth.net>
> Date: Sunday, February 28, 2010, 1:54 PM
> Several have asked about the
> degaussing coil that I used to receive the Alpha 
> signals.
> 
> The coil is the degaussing coil of wire removed from a CRT
> TV.  I think this 
> type of auto degaussing coil was added to color sets made
> after the late 60s or 
> so.  I suspect the TV service degaussing coils used in
> the early sets have much 
> more wire and probably are self resonant way below 10 KHz.
> 
> Here's a pic, coil with LM386 audio amp:
> 
> http://www.w4dex.com/vlf/degaussing_coil_a.jpg
> 
> The audio amp is needed to receive Alphs with Winrad but
> not when using a SLM.
> 
> (An hour later)
> 
> I located a home brew degaussing coil I made in the
> 60s.  Back then color TVs 
> didn't have built in degaussing coils so occasionally a
> color TV's CRT needed to 
> be degaussed to keep the colors clean.  Especially
> when a high current device 
> like a vacuum cleaner was turned on or off while near the
> set.  I'm sure 90% of 
> the subscribers on this group already know that :)
> 
> Anyway this coil is self resonant at 5 KHz:
> 
> http://www.w4dex.com/vlf/degaussing_coil_b.jpg
> 
> Dex
>