[Elecraft] Off Topic - CME

[Fred Jensen]

On 4/27/2011 9:33 AM, Ron D'Eau Claire wrote:
> The magnetic field disturbance that accompanies such events can cause
> problems with systems that have hundreds of miles of wire strung on poles
> (e.g. power transmission and telephone lines), but, AFAIK, it takes a huge
> "antenna" like that to threaten terrestrial gear.

I've been assured that is the case.  I believe the "wavelength" of these 
disturbances is very large, thus taking a very large aperture "antenna" 
to intercept much energy.  Hundred or thousand km transmission lines 
would be the ultimate Beverage antenna for them.

> I know some satellites have been disrupted - even damaged - by magnetic
> storms.

If you mean the barrage of high speed particles that accompany the CME 
magnetic fields, that's true [says the retired systems engineer 
confidently].  Despite radiation hardened semiconductors, the particles 
do damage them.  In general, satellites are not really affected by 
changing magnetic fields [except those whose mission is to measure or 
respond to the fields :-)]

If the Z-component of the Earth's magnetic field is positive [i.e. 
North-pointing], it blocks a great deal of the particle flux.  If it's 
negative when the solar poop arrives, most of it gets through, big 
auroras, high K, high A.  Maybe it's the other way around, I can never 
remember, but one way is "door closed," and the other is "door open." 
In any case, I seriously doubt this is an issue for hams except that in 
a big storm, the bands close.

The good news is, "CME's are short-lived, Cycle 24 will go on." 
SFI=108, A=1, K=1, SSN=57 right now.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2011 Cal QSO Party 1-2 Oct 2011
- www.cqp.org