Here is a related idea: We have seen with JT65a that sometimes when we think the band is closed, it is just very poor instead. W1AW, which one can sometimes hear all lone on the high bands (due to its power and antennas) shows us this as well. I..e., what we assume is no communications may in fact be just very noisy.
Shannon tells us there is no limit to the S/N we can tolerate if we reduce the data rate. So there may be a place as well for a repeater that receives lower-power stations slowly and retransmits them as higher power faster, even though it it couldn't then do the clever interleave that Bonnie proposes for other situations. This idea would be somewhat like VHF FM repeaters, as they use the limiting feature of FM to discriminate a noise-free low-power signal and then retransmit. Instead, it would decode a low baud rate, ECC'd signal to obtain a noiseless signal to re-encode and retransmit. Leigh/WA5ZNU On Mon, 14 May 2007 3:22 am, bruce mallon wrote: > Then DO IT and let the FCC rule ..... > > Just remember for your long distance digipeaters to > work the band must be open ..... > unless your going to use ECHOLINK and if so whats the > point ? > > > --- expeditionradio <[EMAIL PROTECTED]> wrote: > >> Like many kinds of interesting digital >> communications, it seems that >> this sort of digital repeater falls into the gray >> area of FCC rules. >> The "retransmit" rules may preclude it. Welcome to >> Technology Jail. >> Nothing should stop an operator in another country >> from setting one >> up, it it could be used by US operators. >> >> Bonnie KQ6XA >> >> >> >> > This type of single channel HF digital voice >> repeater is perfectly OK >> > under USA's present FCC rules, and the rules of >> most other countries. >> > >> > Bonnie KQ6XA >> > >> > > > Digital Voice repeaters, using single-channel >> > > > near-real-time >> > > > interleaved multiplexed OFDM, could work in a >> 5kHz >> > > > bandwidth. >> > >> >> >> > > > > > ____________________________________________________________________________________Pinpoint > > customers who are looking for what you sell. > http://searchmarketing.yahoo.com/ > > > Announce your digital presence via our Interactive Sked Page at > http://www.obriensweb.com/drsked/drsked.php > > Yahoo! Groups Links > > >
