[aprssig] APRS low-power-local ALT input channel

David Rush david at davidarush.com
Sun Sep 26 10:51:26 CDT 2004

First of all, I don't believe that Bob ever intended for the system he 
proposed to transmit blindly on 144.390.  He proposed a system that would 
move low-power, receiver-less trackers to 144.990.  Dual-port digis would 
listen on 144.990 for packets to digipeat, then listen on 144.390 before 
they digipeat them on 144.390.  Thus low-power receiver-less trackers would 
never interfere with anyone on 144.390.

Second of all, receiver-less trackers are not guilty of intentional 
interference.  Yes, they will on occasion interfere with another station, 
but it's not intentional.  Whether or not this is an acceptable situation 
in limited deployments is another issue.

David, KY7DR

At 10:11 PM 9/25/2004, you wrote:
>I hope this never takes place on a wide scale. Special events, yes, maybe 
>it may work temporarily without too much detriment to the other users.
>To advocate listening on one frequency and transmitting on another without 
>some kind of CD, is asking for some serious kind network failures!
>I am not aware of any trackers or base stations or digipeaters that do 
>this now. If a tracker can not hear another station or CD, then it has the 
>right to transmit. If a digipeater, or base station, does not hear another 
>station, or NO CD, then it has the right to transmit..
>But to just blatantly come up and digipeat a low power signal from another 
>frequency with out CD on 144.390, is "intentional interference". It is not 
>Aloha. Isn't Aloha "Transmit if you don't hear another station" and the 
>digipeaters or home RELAYs will sort it out?
>Even in a busy area like Chicago, I can track several 5 watt trackers when 
>they are on.
>I hope this can be sorted out before hundreds of stations jump on this 
>without fully understanding what may happen..
>aprssig mailing list
>aprssig at lists.tapr.org

More information about the aprssig mailing list