rabruner at aol.com
rabruner at aol.com
Wed Aug 13 00:05:14 CDT 2008
The average power stations are using on UHF for digital is 200 to 400KW.?A great many analog UHF stations operate with 4 to 5 Megawatts, erp, so there is a savings in power for all full power UHF stations.? VHF stations will generally have higher power bills if they move to UHF, but feel that it's worth it to get the cleaner more trouble free propagation on UHF. The VHFchannels, and particularly the low-Vs, 2 -6 are plagued with interference from ghosting and tropospheric ducting and other propagation anomalies.? The only appeal a low V frequency would have for a tv station is the relatively small transmitter employed on those frequencies.??
????Most low power TV stations, those that?serve limited audiences with signals of less than 10kw, will not have to go digital, though those who don't face the issue of not being receivable off the air on the new digital only set top boxes. Some of these do have a pass through feature, but most do not.
??? As for all the frequencies that are being vacated, the FCC is going to auction them off to people who wish to exploit them for commercial purposes, such as selling more two way radios and other devices.
??? Strictly speaking there are no "sub channels" on digital TV, though this terminology is common among the dentists and lawyers who inhabit the consumer forums and chat rooms on the net.? There is one 19.3 mb data stream coming out of the transmitter and it's bits can be assigned in any way the station chooses.? They can all be put into one very high quality HDTV signal, or divided equally among other services.? They don't even have to be television services, as long as there is at least one service that is a digital television picture.? You could have open or encrypted data, Internet connectivity, Mobile TV, or SDTV as well as HDTV.? None of these services is a sub channel of any of the others.? They are all out there on the mux, and the key to picking them off is transmitted as meta data in a group of bits known as PSIP.? The PSIP is the organizing force and it gives names and channel numbers and so forth to what is other was just a hugh spray of data coming out the antenna . ..
Date: Tue, 12 Aug 2008 11:20:02 -0400
From: "WB4JFI" <wb4jfi at knology.net>
Subject: RE: Broadcast new
To: "Nan and Sandy Sanders" <radiodog77 at pobox.com>, "WB4JFI"
<wb4jfi at knology.net>, "Robert Stratton" <bob at stratton.net>, "Michael
O'Dell" <mo at ccr.org>, <W4KRL at arrl.net>
Cc: tacos at amrad.org
Message-ID: <MFEJKJHLHKBOAKAIHKIDIEPBCDAA.wb4jfi at knology.net>
Content-Type: text/plain; charset="us-ascii"
I'm not sure. Right now, there are at least a couple dozen stations around
the country that are staying on their low-VHF channels for DTV. The
operating costs of running a 1 mega-Watt ERP transmission system will
completely overwhelm small station budgets. So, some selected to go with
their "poor" low-VHF coverage, and hope cable & satellite fix their coverage
issues as much as possible.
Oterhwise, yes, the antenna for a wireless device on low-vhf is a
show-stopper. You can have a tiny cell phone, but with a 4ft whip... like
the WWII walkie-talkies.
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