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[aprssig] 220 MHz transceivers

Chris Rose kb8uih at sbcglobal.net
Mon Nov 17 01:13:16 UTC 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
> > 
> > 
> 
> 
> _______________________________________________
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