Like tropo--except it's AM!

[markwa1ion@aol.com]

<<
Dan Strassberg pondered:

> Last night and early this morning I picked up some AM stations I've
> never heard in Arlington. ...

> This is high-angle skywave, which suggests--I believe--that the
> reflective layer of the ionosphere is unusually low overhead. I can
> offer no explanation for that phemomenon. Maybe someone else can.
>>

I've always noted a lot of short skip in late spring and summer.

In summer '65 when Hartford's WDRC (1360) and WPOP (1410) were both 
great Top 40 stations, they delivered nice clean signals just about 
every evening during the warm months.  WPTR-1540 Albany - another 
legendary Top 40 then - was huge and had little or no interference.

At the time, I was living near the western edge of Menotomy Rocks Park 
in Arlington, not very far (under 2 miles) from where Dan is now.

In the wintertime, 1360 had interference to WDRC from WSAI 
(Cincinnati), 1410 had WPOP wrestling with WING (Dayton, OH) as well as 
PA and DE stations, and while WPTR still had a good signal on 1540, you 
had KXEL from Waterloo, IA under it with assorted preachers and country 
tunes later at night.

So, in conclusion, short skip ... under 200 miles ... is pretty much a 
seasonal thing (better in spring / summer, and yielding to longer skip 
in autumn / winter).  This is relatively independent of the solar cycle.

Solar cycle variations would manifest themselves more in terms of more 
short-duration blackouts / aurora during high parts of the cycle.  In 
those cases most higher latitude skip gets wiped out and a narrow area 
of the ionosphere along the southern horizon does all the "bouncing".  
Those who chase DX find good Latin American action on such auroral 
nights, especially if they have water south of them such as on the 
Nantucket Sound facing shore of the Cape.

Mark Connelly - Billerica, MA