Is the rule still 500 feet to broadcast up to?
Is that for also Radio Broadcasting?
Is that for also Radio Broadcasting?
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TV Transmitters
- Thread starter MarioMania
- Start date
No one at all
It was never 500 feet, at least not since the early 1950s.
It was 2,000 feet in most of the country -- 1,000 feet for VHF stations in the Northeast and Great Lakes.
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Since the early 1960s it's indeed been 500 feet for FM radio in the Northeast, Great Lakes, and most of California. It's 2,000 feet elsewhere. This is for a station of maximum class. There also exist Class A FM stations which were originally limited to 300 feet. That figure was changed to 328 feet (100 meters) when the FCC went metric.
More recently, several other classes of FM station have been created. Class B1 and C3 have the same limit as Class A; class C2 stations are limited to 500 feet in the area where 2,000 feet is normally allowed; Classes C1 and C0 are limited to roughly 1,000 and 1,500 feet respectively in the 2,000-foot zone. (all classes are now defined in the metric system)
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In all cases, higher antennas are permitted if power is reduced to compensate.
Also, until the early 1960s there was no limit outside the northeast. When the limits were imposed, stations that were already exceeding them were not required to reduce. As a result, most major stations in California -- and a few handfuls elsewhere -- use powers that would not be permitted today at their antenna heights.
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There is no maximum antenna height limit for AM stations. In practice off the top of my head I can't think of any AM towers taller than 1,000 feet -- maybe Scott Fybush can correct me on that
. There are definitely AM towers significantly higher than 500 feet.
It was 2,000 feet in most of the country -- 1,000 feet for VHF stations in the Northeast and Great Lakes.
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Since the early 1960s it's indeed been 500 feet for FM radio in the Northeast, Great Lakes, and most of California. It's 2,000 feet elsewhere. This is for a station of maximum class. There also exist Class A FM stations which were originally limited to 300 feet. That figure was changed to 328 feet (100 meters) when the FCC went metric.
More recently, several other classes of FM station have been created. Class B1 and C3 have the same limit as Class A; class C2 stations are limited to 500 feet in the area where 2,000 feet is normally allowed; Classes C1 and C0 are limited to roughly 1,000 and 1,500 feet respectively in the 2,000-foot zone. (all classes are now defined in the metric system)
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In all cases, higher antennas are permitted if power is reduced to compensate.
Also, until the early 1960s there was no limit outside the northeast. When the limits were imposed, stations that were already exceeding them were not required to reduce. As a result, most major stations in California -- and a few handfuls elsewhere -- use powers that would not be permitted today at their antenna heights.
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There is no maximum antenna height limit for AM stations. In practice off the top of my head I can't think of any AM towers taller than 1,000 feet -- maybe Scott Fybush can correct me on that
. There are definitely AM towers significantly higher than 500 feet.I have a UHF Video Sender, the Box say up to 500 ft
I'm in California -- but I lost the antanna that came with it, So it only goes up to 50 ft with homemade one from a hanger
I'm in California -- but I lost the antanna that came with it, So it only goes up to 50 ft with homemade one from a hanger
w9wi said:There is no maximum antenna height limit for AM stations. In practice off the top of my head I can't think of any AM towers taller than 1,000 feet -- maybe Scott Fybush can correct me on that
As long as the low end of the AM dial is at 540 kHz (and thus about 500 meters in wavelength), there's not much practical reason to have an AM tower taller than 1,000 feet. The height champions in the US are the night antenna of WRDT 560 in the Detroit market (203 electrical degrees at 560 makes for 992' of electrical height...which would be one ridiculously tall tower for 13 watts were it not also the support tower for several Detroit-market FMs) and WNAX 570 in Yankton, SD, which is 190 degrees at 570 on its day tower, or 910' of electrical height for the tallest AM-only tower out there. (The actual tower gets to 927' above ground with the base and insulator and top beacon included.)
But I suspect w9wi already knew that...
MarioMania said:
Oh, you meant that question in a completely different sense!
The maximum permissible distance for unlicensed transmission in TV channels is zero.
Very low powered unlicensed transmission like this is legal in the AM and FM radio bands but it's not allowed on TV channels.
Which doesn't mean there isn't plenty of illegal equipment on the market!
Thanks for the Info..
D
Darth_vader
Guest
Probably hasn't stopped anybody from connecting an aerial to the RF *out* port of their VCR, though, has it?
Didn't think so!
That doesn't even go for, I tried it...Even with a good antanna hooked up
D
Darth_vader
Guest
Having a bit of déjà vu there, Mario?
It helps to have a VCR with a powerful-enough modulator. On my Panasonic PV-9662 in the apartment, I could transmit barefoot on 4 with a rabbit-ears from the central "living room" area into the kitchen and into the bedroom about 20 feet away, somewhat clearly. With the VCR feeding the input terminal of an amplifier and an improvised half-wave speaker wire dipole, I could get to the building across the parking lot, about 60 feet out.
I guess it depends on the quality and type of your equipment and its operating environment (thus, past performance does not guarantee future performance.)
It helps to have a VCR with a powerful-enough modulator. On my Panasonic PV-9662 in the apartment, I could transmit barefoot on 4 with a rabbit-ears from the central "living room" area into the kitchen and into the bedroom about 20 feet away, somewhat clearly. With the VCR feeding the input terminal of an amplifier and an improvised half-wave speaker wire dipole, I could get to the building across the parking lot, about 60 feet out.
I guess it depends on the quality and type of your equipment and its operating environment (thus, past performance does not guarantee future performance.)
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