[aprssig] 220 MHz transceivers
Chris Rose
kb8uih at sbcglobal.net
Sun Nov 16 20:13:16 EST 2008
OK,
I'm not that far gone yet.
:)
Chris
KB8UIH
--- On Sun, 11/16/08, Scott Miller <scott at opentrac.org> wrote:
> From: Scott Miller <scott at opentrac.org>
> Subject: Re: [aprssig] 220 MHz transceivers
> To: "TAPR APRS Mailing List" <aprssig at tapr.org>
> Date: Sunday, November 16, 2008, 6:37 PM
> And if you're still confused, see this:
>
> http://www.youtube.com/watch?v=AMeaX8Kz2TM
>
> (Sorry, couldn't resist...)
>
> Scott
> N1VG
>
> Stephen H. Smith wrote:
> > Chris Rose wrote:
> >> 85MHZ is fm commercial broadcast range. Anything
> local to you there?
> >>
> >>
> >>
> >
> > The bottom of the FM broadcast band is 88 MHz with a
> (very) few minor
> > stations on 87.9.
> >
> > 85 MHz is the center of NTSC (North America) TV
> channel 6 which extends
> > from 82 to 88 MHz. I through of this, but neither
> the visual or sound
> > carriers of this channel land on the frequency
> originally mentioned.
> >
> >
> >
> > Speaking of TV channels, I am predicting a MAJOR
> renaissance of
> > six-meter activity next year.
> >
> > Channel 2 (54-60 MHz) has rendered 6M operation
> almost impossible in
> > many major cities of North America. Even when the
> lower visual
> > sideband of channel 2 is suppressed 60-70 dB (from a
> quarter-megawatt or
> > more), the net result is to blanket most of the
> 6-meter band with
> > S9-plus sync hash and noise. Not to mention the
> potential for
> > interference to TVs from 6M transmitters (TV tuners
> with lousy adjacent
> > channel rejection). This will change radically 17
> February 2009.
> >
> >
> >
> > The chaotic transition to all-digital TV broadcasting
> in the US has
> > stations currently simulcasting on analog and digital
> channels. Nearly
> > all digital transmission is currently in the UHF band.
> After the analog
> > shutdown next Feb 17, about half of the VHF HIGH-band
> TV stations (chans
> > 7 through 13) will move their digital operation to the
> classic VHF
> > channel occupied currently by their analog operations.
> The other half
> > will just shut down the analog operation and continue
> the digital
> > operation on UHF only, although there is going to be a
> lot of jumping
> > around from one UHF channel to another.
> >
> > To add to the confusion, the (UHF) digital channels
> identify with the
> > VHF channel numbers of their legacy analog counterpart
> stations no
> > matter what channel they are actually on. [The
> digital transmission
> > protocols allow you to send any arbitrary channel
> number as part of the
> > transmission.] For example, here in Los Angeles, the
> station that shows
> > up on my digital TV as "Channel 7.1
> KABC-DT" is actually on UHF channel
> > 57, but will move to the "real" channel 7
> when the analog side shuts
> > down.
> >
> >
> > However, virtually ALL analog LOW-band TV stations
> (chans 2 through 6)
> > will just shut down the analog operations, and
> continue their current
> > digital operations on UHF only. A new generation of
> "all-channel" TV
> > antennas from Channel Master and Winegard are now on
> the market. They
> > are about half as large as their traditional versions,
> because they no
> > longer cover the low-VHF band.
> >
> > The bottom line is that channel 2 is going away
> COMPLETELY!!! Not
> > just going digital but going silent which will make
> the 6 meter band
> > instantly far more usable than it is now.
> >
> > Lots of info on the DTV channel changes and
> re-assignments at this website:
> >
> > <http://rabbitears.info>
> >
> >
> >
> >
> >
> > --
> >
> > Stephen H. Smith wa8lmf (at) aol.com
> > EchoLink Node: 14400 [Think bottom of the 2M
> band]
> > Home Page: http://wa8lmf.com --OR--
> http://wa8lmf.net
> >
> > World Digipeater Map
> > http://wa8lmf.net/APRSmaps
> >
> > JavAPRS Filter Port 14580 Guide
> > http://wa8lmf.net/aprs/JAVaprsFilters.htm
> >
> > "APRS 101" Explanation of APRS Path
> Selection & Digipeating
> > http://wa8lmf.net/DigiPaths
> >
> > Updated "Rev H" APRS
> http://wa8lmf.net/aprs
> > Symbols Set for UI-View,
> > UIpoint and APRSplus:
> >
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > aprssig mailing list
> > aprssig at tapr.org
> > https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig
> >
> >
>
>
> _______________________________________________
> aprssig mailing list
> aprssig at tapr.org
> https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig
More information about the aprssig
mailing list