-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
DXing
- Thread starter Barkoff
- Start date
Radio communication that occurs with assistance of atmospheric conditions.
You can hear it on the MW AM broadcast band at night.
The atmosphere bends the signals back to Earth at a distance not achievable by the signal traveling directly from it's source to your receiver.
You can hear it on the MW AM broadcast band at night.
The atmosphere bends the signals back to Earth at a distance not achievable by the signal traveling directly from it's source to your receiver.
Many local AM broadcast stations are required by the FCC to reduce their output power at night, so that is why their signal is so much weaker.
And... yes, the distant stations get the benefit of the "bounce", and local stations do not.
Nighttime AM broadcast dx can really be fun. There are quite a few "clear-channel" nighttime stations out there.
WIBC-Indianapolis
WLS-Chicago
KMOX-St Louis
KDKA-Pittsburg
KXEL -Waterloo, Iowa
WRVA-Richmond, VA
WLAC-Nashville,TN
and many others. Use the web to find their freqs.
- 399
'DX' is a radio abbreviation for distance. So, 'DXing' means seeing how far you can hear or communicate.
There are lots of reasons why what you can hear changes from day light to dark. Primarily, what you can hear deals with propagation, how a signal 'bounces' off of the ionosphere. And then the fact that some stations decrease/increase output power at various times, and also the direction they happen to be transmitting. Propagation also is frequency dependent, different frequencies propagate (bounce) differently. The color of the grass around a stations transmitting antenna can also be an indication of how well it will be heard, believe it of not! Nothing to do with the grass at all, but with the 'quality' of the electrical ground of the antenna. Moisture tends to make for a 'better' ground, typically, which will change the radiation characteristics of an antenna. (Geeze! Now I gotta worry about the color of grass?)
Ain't all this 'stuff' fun!?
- 'Doc
There are lots of reasons why what you can hear changes from day light to dark. Primarily, what you can hear deals with propagation, how a signal 'bounces' off of the ionosphere. And then the fact that some stations decrease/increase output power at various times, and also the direction they happen to be transmitting. Propagation also is frequency dependent, different frequencies propagate (bounce) differently. The color of the grass around a stations transmitting antenna can also be an indication of how well it will be heard, believe it of not! Nothing to do with the grass at all, but with the 'quality' of the electrical ground of the antenna. Moisture tends to make for a 'better' ground, typically, which will change the radiation characteristics of an antenna. (Geeze! Now I gotta worry about the color of grass?)
Ain't all this 'stuff' fun!?
- 'Doc
Doc - just plant bluegrass. Confusion goes away.
From my home town, Las Vegas, one of the best stations to listen to at night is KOMO, in Seattle. Right at 1000 on the AM dial.
First time I ever heard it was in 1958 on an old Hallicrafters SX99 receiver which I'd just bought second-hand from a schoolmate (K7BRW) who'd upgraded to an SX-101. Just tuning around the AMBC band and found this strong station with a frequency of exactly one "megacycle". I couldn't quite make out the station ID so I listened a bit more closely and the announcer said, "...and now from KOMO, here's Perry!" and proceeded to play "Round and Round" by Perry Como.
Nowadays, KOMO is only about 22 miles from my house, still 1000 AM, and Channel 4 (ABC) on TV.
From my home town, Las Vegas, one of the best stations to listen to at night is KOMO, in Seattle. Right at 1000 on the AM dial.
First time I ever heard it was in 1958 on an old Hallicrafters SX99 receiver which I'd just bought second-hand from a schoolmate (K7BRW) who'd upgraded to an SX-101. Just tuning around the AMBC band and found this strong station with a frequency of exactly one "megacycle". I couldn't quite make out the station ID so I listened a bit more closely and the announcer said, "...and now from KOMO, here's Perry!" and proceeded to play "Round and Round" by Perry Como.
Nowadays, KOMO is only about 22 miles from my house, still 1000 AM, and Channel 4 (ABC) on TV.
One of the reasons why local AM stations appear to have a weaker signal at night is, as has been mentioned, the requirement to lower power or switch patterns at night. Sometimes the far off DX station just plain overpowers the local as well. In some cases,depending how far you are from the local station, you can be within range of both the ground wave signal and the skywave signal at night.It is quite possible for an AM station to have a skywave signal received from very close,sometimes only 20-30 miles away. When this happens the two signals combine and shift in and out of phase causing fading and generally poor signal quality even if there is no other station on frequency causing interferance.