ems@BBN.COM> (01/11/90)
In article <6043@alvin.mcnc.org> spl@mcnc.org.UUCP (Steve Lamont) writes: >There are some antenna systems which PURPORT to emit an omnidirectional pattern >(the FCC, in fact, MANDATES that all FM and, if I recall, all TV to be >omnidirectional), although numerical analysis as well as actual measurement >indicate that no such beast exists. I'm confused (a not unusual state for me ...) Why would the FCC want folks to have an omnidirectional pattern? Most of the population lives near one coast or another (West, South, or East). Why would they want a TV station in, say, New York, to radiate half of it's power out to sea? In other areas the city is often in a valley surrounded by nice hills or mountains. Why would an FM station want to send half it's power into the hills/desert/national wilderness rather than into the valley with the people and cars? I don't understand ... -- E. Michael Smith ems@apple.COM 'Whatever you can do, or dream you can, begin it. Boldness has genius, power and magic in it.' - Goethe I am not responsible nor is anyone else. Everything is disclaimed.
Steve Lamont <spl@MCNC.ORG> (01/12/90)
In article <6132@internal.Apple.COM> ems@Apple.COM (Mike Smith) writes: >I'm confused (a not unusual state for me ...) Why would the FCC want >folks to have an omnidirectional pattern? Most of the population lives >near one coast or another (West, South, or East). Why would they want >a TV station in, say, New York, to radiate half of it's power out to sea? Beats the heck out of me, but it is in the Rules and Regulations -- or at least it was when I was actively involved in broadcast engineering about 7 years ago. I'll check with some of my broadcast engineer friends and give you an update. >In other areas the city is often in a valley surrounded by nice hills or >mountains. Why would an FM station want to send half it's power into >the hills/desert/national wilderness rather than into the valley with >the people and cars? I don't understand ... See above. As I recall, the rationalization that was given to me had something to do with giving equal service to all markets and/or locales. Again, I'll check and post what I find out. spl (the p stands for propagation used to be my middle name until I discovered confusers) -- Steve Lamont, sciViGuy (919) 248-1120 EMail: spl@ncsc.org NCSC, Box 12732, Research Triangle Park, NC 27709 "That's People's Commissioner Tirebiter -- and NOBODY'S sweetheart!" - F. Scott Firesign
carroll@BEAVER.CS.WASHINGTON.EDU> (01/14/90)
I'd refer anyone interested in these topics to the November 1982 issue
of Proceedings of the IEEE, which is devoted to UHF TV broadcasting. It
includes articles on coverage, CP transmission, and several other
aspects of UHF TV.
Jeff Carroll
carroll@atc.boeing.com
:wq