Nate is correct in that the frequencies listed were the center freq of each channel. There are 14 channels. And yes, I forgot the decimal. Oh well I am old as well as tired. The channels overlap each other in that they are 22 MHz wide ( NO decimal) One can do the math and see which channels edge falls outside the Amateur band if you wish but if you do not run an amplifier, who cares.
If my memory serves me 802.11 concept began in the late 80's and there were two forms approved by the FCC. One was DSSS (Direct Sequenced Spread Spectrum) that is used today and the other was FHSS (Frequency Hopping Spread Spectrum) that consisted of 75 channels spaced 1 MHz apart and traffic jumped between those channels. In 1999 the industry selected 802.11b as the standard with its max 11 Mbps. Of course we now have everyone pushing the 802.11g that have a maximum of 54 Mbps but we seem to forget that many access points use 10 base T Ethernet connections so you are limited to 10 Mbps anyway. Remember as the signal gets noise due to low signal strength the speed is decreased. I use 802.11g but often have only Mbps speed due to low signal strength. Still pretty fast as I have seen T1 that was only slightly higher is speed. With a good antenna it possible to get amazing distance. I have sent video with p1 picture to my brother Jim,KA8HAK over in Akron 16 miles from me. I was using 1 watt into 140 feet of 7/8 hard line to a 3 foot dish at 85 feet. He was using a home brew 44 element linier yagi on a tripod 7 feet in the air fed with LMR400! Until last year I had an FM repeater (2.411200 out / 2.431200 GHz in) on the air. It also ran 1 watt and had a 20 meg split. Worked pretty good but there were only three of us that could transmit. Jim KZ5AW, my brother Jim KA8HAK, and myself. Perhaps one day I will put it back on if equipment become more reasonable and others become interested. Oh well - enough of the rambling and at least I said something about repeaters.. 73 P.S. Nate, I am glad I gave you a laugh at the no decimal. One of my goals is to make someone laugh each day even if they are only laughing at me! It was a good day as is most of them.. Rich WA8DBW http://www.wa8dbw.ifip.com ----- Original Message ----- From: "Nate Duehr" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, December 09, 2004 12:31 PM Subject: Re: [Repeater-Builder] Re: 802.11b wireless > > Careful! That channelization map only shows the CENTER frequency of the > direct-sequence spread-spectrum "channel" you're using. I believe Mr. > Reese is incorrect in his statement that channels 7 and 8 are in the ham > band. > > Each "channel" overlaps the "channels" around it -- they're wide. > > (Our old pal Nyquist's pesky theorem might point out that there's not > enough bandwidth between from say, 2417 to 2427 to do a 11Mb/s data > stream on Channel 3, and that's assuming you would run right up against > channels 2 and 4. But, I sure as hell can't do the math without having > had any coffee yet today!) > > The access points just deal with the interference they cause each > other. When you're laying them out for use in an office building, you > pick patterns that use 1, 6 and 11 to keep all the AP's out of each > other's hair. > > Channels 1, 6, and 11 are the only "channels" that don't overlap each > other in the U.S., so channel 1 extends up through Channel 3 (and below > channel 1 down to just above 2400 MHz), and Channel 6 extends downward > to Channel 4 and upward to channel 8. > > So the highest usable "channel" if you want to operate as a Part 97 > station is Channel 6 if I didn't screw up my math. Or the top portion > of your signal will be out of the ham allocation. ;-) > > I got a kick out of the 24XX "GHz" label too... that's pretty high! > (GRIN) > > Nate WY0X > > JOHN MACKEY wrote: > >>It should be noted, also, that the channels are overlapping on each other. >>The only channel setup that would NOT be overlaping it using channels 1,6, >>& >>11. >> >>There are also channels 12, 13, & 14 but they are not authorized in the >>US. Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
