[IRCA] Groundwave strength changing from day to night. Robins in spring.

[Charles A Taylor <MWDXer@xxxxxxx>]

Dennis,

As far as I know (and I'm not sure how far I know, except it doesn't seem 
far enough) , groundwave signals DO NOT propagate any better during 
daylight hours. I surmise from what you've written, that what you're 
experiencing is nighttime skywave limiting groundwave coverage of your 
locals and semilocals.

In this case, the groundwave field intensity of your local station should 
be the same at night as it is during the day. But the nighttime skywave 
signals make it appear weaker.

Another factor is skywave radiation from your locals' towers. If they're 
radiating skywave, as in towers over about 5/8 wavelength (0.625), then the 
skywave will selectively add to and subtract from the groundwave., as the 
ionospheric refraction changes from moment to moment.

BTW, the mob (flock, flight, gaggle, herd) of robins that I referred to 
earlier haven't seemed to notice the low (for east NC) nighttime 
temperatures. They haven't flown back further south.

I suspect they see one of my longwires (125-footer) and find it 
interesting. Perhaps they will brood/breed in the woods behind our house. 
Imagine that! Maybe some of the young-uns will want to learn about DX. Does 
IRCA accept applications for membership from robins?

73 de Charlie

cold (F)
cold (C)


At 03:43 AM 2/5/2007 +0000, you wrote:
>Bill,
>
>I have noticed that stations on lower frequencies seem to get out better 
>during day time hours.  When I lived in the San Francisco Bay Area, KVIP 
>on 550 kHz in Redding put in a good signal with 5 kw.  Another example was 
>KAFY 550 kHz in Bakersfield, with 1 kw heard often during the 
>daytime.  KSFO 560 kHz with 5 kw also put out a nice signal in the Sierra 
>Nevada mountains.  Their signal was stronger at times than the 50 kw SF 
>stations.  My father told me the reason when I first started Dxing in the 
>60's, but I forgot the reason he gave.  Sure someone on the list will know.
>
>Dennis,
>Vancouver, WA
>48.7 F
>9.27 C
>Cloudy

        -----
Charles A Taylor, WD4INP
Greenville, North Carolina 

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