Bruce, It is uncertain that a typical OFDM 5W signal spread over 100 kHz would have enough power density to break the squelch on an FM receiver.
In other words, FM rigs may not even hear the 100 kHz signal. If they bother to open their squelch, they may note a slight increase in background noise level, but that is about it. Try to think of it this way. You are operating CW using a 250 hertz filter amd a weak SSB signal comes up right on top of you. Chances are you could operate right through it with no problem. Another example of imaginary QRM issues is on 2.4 GHz, where I operate the most. The FM-ATV stations fire up right on top of our HSMM signals all the time. It is accidental. They hear our 20 MHz wide signal as a slight increase in the background noise level. That QRM lowers our data rate a bit, but it is no big deal, so we don't mind sharing the frequency with them at all. They up their power if they need to compensate for us just as you might with any noisy band condition, Sp we peacefully co-exist on the same band and even the same frequencies...sort of, just much different BWs. In a time period shorter than most of us realize, most of the VHF and UHF bands will be all digital. The FCC is moving all other users in that direction anyway. No more WFM, just NFM, etc. They want greater spectral efficiency. Look at D-Star digital voice! It is only 6 kHz bandwidth. John ----Original Message Follows---- From: bruce mallon <[EMAIL PROTECTED]> Reply-To: digitalradio@yahoogroups.com To: digitalradio@yahoogroups.com Subject: Re: [digitalradio] Re: Tearing Down USA's Data Wall (300 symbols/second) Date: Mon, 26 Mar 2007 05:03:22 -0700 (PDT) The ARRL has no clue ..... and do not care ..... When open 6 meters is packed solid from 50.105 to 50.5 with ssb there are AM users on 50.400 and PSK-31 between 50.5 and 50.7 RIGHT NOW the band is closed but it will not be in 2 to 3 years the only open spot is between 50.7 and 51.5 above that are simplex nets and repeaters ..... On 2 meters here in tampabay 144.200 - 144.300 is week signal work with nets on 144.210, 144.250 common here in fl and 144.300 - 144.400 APRS users used in this state. EXCEPT for 146.500 - 146.600 and 147.500 - 147.600 evenything above 146.000 is used be repeaters. simplex nets and users are common on 146.500 ( or 146.490 ) 146.520,146.550 and 146.580 and again on 147.20 55 and 58 now where are you going to put 500 100 khz wide signals? .... EXCEPT on 220 or 440 and only because 220 has no one on it and 440 is so big? --- Mark Miller <[EMAIL PROTECTED]> wrote: > Bruce, > I will "work it out when 6 is OPEN" world wide" and > not interfere > with repeaters on 2 meters because I will continue > to follow the > clause that says "no amateur operator shall > willfully or maliciously > interfere with or cause interference to any radio > communication or > signal" . How does changing the authorized > bandwidth affect the > prohibition on interference? > > 73, > > Mark N5RFX > > > >440 ALSO has NO SKIP and 8 TIMES the space > >NOW how are you going to work it out when 6 is OPEN > >world wide ? > > > >ANYONE with a half a brain knows 6 is not the place > >for this ...... > > > >also how are you not going to interfere with > repeaters > >on 2 meters ???? they cover 3 out of 4 mhz of that > >band ????? > > > ____________________________________________________________________________________ Need Mail bonding? Go to the Yahoo! Mail Q&A for great tips from Yahoo! Answers users. http://answers.yahoo.com/dir/?link=list&sid=396546091
