This has always interested me on patterns after sunset...helps to know how a statio's propagation works and, if using a directional "loop" receiving antenna, wher and how to null out one station and receive another:
This has always interested me on patterns after sunset...helps to know how a statio's propagation works and, if using a directional "loop" receiving antenna, wher and how to null out one station and receive another: This has always interested me on patterns after sunset...helps to know how a statio's propagation works and, if using a directional "loop" receiving antenna, wher and how to null out one station and receive another:
http://www.fcc.gov/ftp/Bureaus/MB/Databases/AM_DA_patterns/72206-7327.pdf
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Nighttime directional patterns are very hard to maintain for some stations. The more elaborate the pattern the more difficult. The F.C.C. used to be very strict about the patterns because they protected other stations. Sometime a new power line or water tower close to a tower could throw off a pattern and cause a lot of expense to bring it back. I believe the chief had to monthly run a check on the pattern to make sure it was in compliance.
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HI AJ,
The Wrightsville water tower was within about a mile from the KAAY transmitter. The legs of the water tower had to be de-tuned (made electrically invisible) to keep the water tower from negatively effecting the KAAY night-time elongated figure "8" pattern. This was done by stringing a piece of wire along each leg of the water tower and then "tuning" them. There was so much power in the free air around the KAAY transmitter that almost anything that could conduct electricity (even sections of barbed wire fence) became part of the KAAY antenna.
/DM/
One thing the "figure 8" protects is KRLD 1080 Dallas. I figured that out back when I'd try to tune in the Rangers baseball games with my dad in Hot Springs. KRLD also augments their pattern to Little Rock. So we could hear it but it was tough. Too bad the games weren't on WBAP, they are omnidirectional 50kw.
If you want to look at a truly directional station, check out KFXR 1190 Dallas. They have a 12 tower array for their night pattern. It was joked that the signal could go down Elm in downtown Dallas, without hitting the curbs.
Neat article here that details how it was built - end of article says it is a different callsign now but it is currently shown as KFXR on the actual FCC site:
http://radiomagonline.com/mag/radio_worlds_largest_battery/
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