Russ Edmunds <wb2bjh@...>
--- On Fri, 11/28/08, bbwrwy <richarda@...> wrote:
One thing I don't understand is why I'm able to hear TP signals when
geomagnetic activity blocks TA reception. From what I can find much
more has been written about how to receive European AM stations than
Have a good weekend.
36°22'51"N / 97°26'35"W
(near Perry OK)
This has to do with the geography of the auroral zone. The auroral zone, given that it is a geomagentic phenomenon, is roughly centered around the magnetic North Pole, which is located in Northern Canada somewhat more South of the geographic Pole than one might at first think.
Thus as the absorption zone is located around it, and the zone is 'pushed' to the darkness side of the earth by the sun, and when NA is on the dark side, we also have to work with that Southward location of the magnetic pole, there is much more absorption on the usual TA paths than there is on similar TP paths, simply because the absorption that gets 'pushed' southward from the magnetic pole interferes more with those paths.
TP paths to your location don't run far enough to the North to encounter the absoprtion, as on those paths, the location of the geomagnetic pole doesn't impact them.
Blue Bell, PA ( 360' ASL )
[15 mi NNW of Philadelphia]
40:08:45N; 75:16:04W, Grid FN20id
FM: Yamaha T-80 & Onkyo T-450RDS w/ APS9B @15'
AM: Modified Sony ICF 2010 barefoot