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Post by thelegacy on Aug 25, 2018 19:39:39 GMT
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Post by part15engineer on Aug 27, 2018 14:49:25 GMT
he thinks he can change the physics of the am band, what will wind up happening in actuality at night is one ginormous clusterfuck!!! and this idea does not address the core problems of the AM Band.
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Post by Boomer on Aug 27, 2018 21:22:53 GMT
Revitalize this! *slap*
There was an anecdote from a broadcaster who worked at a station on a local Class IV frequency, known as a graveyard channel. Every station on that class of channel used to operate at 1000 watts by day, and had to drop power to 250 watts at night. There came a time when the FCC allowed all stations on those frequencies to run 1000 watts day and night. Now with all stations at 1000 watts at night, he found the range was no different, but the signal within that range was better.
That's a special case, where you have many stations on one frequency at the same power. What that piece of revitalization seems to want to do is allow some stations to increase their power where they're in the night footprint of a 50 kw dominant station. It seems that few stations will get to do this and it will just increase interference levels.
Stations are thinking of themselves, as you would do as an owner, but at what price? AM is ruled by interference from other stations at night, so wouldn't more vitality come from reducing that interference?
Maybe it's something that looks good on paper, like someone is taking action and doing something. I haven't seen someone post numbers and charts on an actual example station to show what the impact would be, no breakdown, so it still just talk.
If they do it, we'll see what happens.
Boomer
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Post by Admin on Aug 29, 2018 4:35:44 GMT
Great project! I do hope it gets traction and helps our stations. Jim |
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Post by Boomer on Aug 29, 2018 11:48:37 GMT
Maybe it's such a small change, knowing how things are today, with the AM band being less vital, so it will just go through.
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Rich
Full Member
RF Systems Engr (retired)
Posts: 112
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Post by Rich on Aug 29, 2018 18:52:03 GMT
... now with all (Class IV) stations at 1000 watts at night, he found the range was no different, but the signal within that range was better. ... Just to note that other things equal, increasing the nighttime power from 250W to 1kW for all Class IV AM stations increases their groundwave field AND their nighttime, interfering fields from each of the other co-channel Class IVs by the same amount: 6dB, or twice what it was at 250W. So to an AM receiver, the net difference in nighttime performance between 250W and 1kW Class IV AM stations is about zero. |
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Post by Boomer on Aug 29, 2018 21:11:07 GMT
Here's where my info on nighttime interference and Class IV stations comes from.
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EXPERIMENTAL BROADCASTER'S NEWSLETTER Vol. 2, No. 4
Letters continued
Rebuttal:
Re- March issue: I take exception to remark made concerning Class IV stations
doubling range at 1 KW night time.
Theoretically, true! In practice, NO DIFFERENCE in range by operating 1 KW nights.
Why? Because everybody else is also running 1 KW and you get nailed by Heterodyne...
At WYGL, Selinsgrove, PA (where I work weekends), I find we're getting out no
further at night than when we ran 250 watts. However, we are heard better in the area
we do cover at night . . . . Just my 2 cent's worth.
R.F.H.
Editor's reply: Your 2 cent's worth is appreciated. There is nothing like first-hand
experience in the field to get at the truth of the matter. It appears I understated the
case when I said "Some new interference may be noted at times."
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Boomer
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