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[aprssig] Feeding multiple stations into one for digipeating?

Robert Bruninga bruninga at usna.edu
Mon Jun 12 03:36:54 UTC 2006


>>> mwrobertson at comcast.net 06/11/06 5:08 PM >>>
>And I would also add,... the BIG tall transmitter would be 
>transmitting without ever listening to the busy local area 
>network on 144.390. This is rediculous!!!

Ah, Thats just what I said.  See item (a) "it gives local priority"
and I also said " A unique result which may have some 
application in some area for a special event".  Meaning, 
if you are doing something that you care most about
getting local packets heard, and dont care about DX coming
in from out or area, then this is the design I proposed.
No more, no less.

>When the low level WIDE1-1 would send each packet on 
>144.990, then the digipeater in question would immediately 
>transmit that packet without any regards to other traffic 
>on 144.390. Ludicrous!

Yep, simply depends on what  you want.  Typically, 96 to 98%
of ALL packets at most digis back east come from out of that 
digi's direct area.  Meaning only 2 to 4% of ALL packets are 
direct to the digi and yes, those 2 to 4% of all packets would 
get priority at the expese of only 2 to 4% of the DX QRM.  
Some areas prefer it that way, to give LOCAL mobiles priority.  
So this is not Ludicrous if that is what they actually  want locally.

But yes, ludicrous if you want to give DX packets equality
with locals and allowing them to potentially collide with 
local packets 96 to 98% of the time.

So again, only apply what meets your local goals.  APRS
is a local system to meet local needs.  de WB4APR, Bob


Robert Bruninga wrote:

>TO set up a multi-receive site APRS central digi:
>1) Set main digi to input on 144.99 and TX 
>    on 144.39 supporting WIDEn-N
>2) Set remote receive sites to listen on 144.39 
>    and TX on 144.99 supporting WIDE1-1 only.
>Result would be 
>a) Priority access to all locals in range of any of the receivers.
>b) Each lower remote receiver would hear less DX QRM
>b) Nothing from anywhere else would get through since they 
>    would have to go through a WIDE1-1 to get to the main digi.
>An interesting arrngement with minimal hardware and
>only operating normally 144.39 but with + and - 600 offsets.
>A unique result which may have some alpplicaion in some
>area for a special event.
>
>Bob, Wb4APR





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