[aprssig] I may be setting up a digipeater

Keith VE7GDH ve7gdh at rac.ca
Wed Oct 3 13:18:30 EDT 2007


Joe NE3R wrote...

> The digi will probably be a 144.99 input and 144.39 output, since
> there is another digi nearby. I don't have much experience here, but
> I'm thinking that the Alinco with the T2-135 would be easy to deploy
> and maintain. The main function for this digi would be to transmit
> the local repeater object since doing that from my home station isn't
> the most reliable solution due to antenna restrictions.  Any
> suggestions will be most welcomed.

Technically, that could be done, but with the DR-135 listening on 144.990 
and transmitting on 144.390 it wouldn't have any way of knowing when the 
frequency was clear. If it was both listening and transmitting on 144.390 it 
would at least know if another station or digi within earshot was already 
transmitting. If the frequency is very lightly used, the chances of 
clobbering other beacons would be a lot lower, but a 144.990 in / 144.390 
out digi would be better with two TNCs and a transceiver on 144.390 so it 
could listen before transmitting.

What is the coverage of the "other digi" like? Would your digi be providing 
similar coverage? What is the terrain like? Would either your digi or the 
other digi have coverage similar to the voice repeater? It's definitely a 
good thing to generate an object for the voice repeater, but it should go 
out direct with no path and ideally from a digi having coverage similar to 
that of the voice repeater. If the other repeater and the voice repeater are 
high up, the network might be better off with the other digi generating the 
object. Regardless, try and determine if a digi is actually needed... 
WIDEn-N if it's high up, WIDE1-1 if it's a fill-in digi helping mobile 
stations get to the WIDEn-N digi. That should be the first decision.

You are right about the T2-135 being easy to maintain. You can reconfigure 
it at any time with an APRS message.

73 es cul - Keith VE7GDH
--
"I may be lost, but I know exactly where I am!" 





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