[App_rpt-users] Co-located Split Site Repeaters

[Brett Friermood]

On Sun, Feb 2, 2014 at 2:00 PM, Steve Wright <stevewrightnz at gmail.com> wrote:
> Ok unless I have misread, we have two opposing opinions stated as fact.
>
> Anyone care to offer insight, quote sources or offer configs, or otherwise
> generally assist in the scientific principle of distilling collective
> opinion for fact?

I'll take another shot at it. First, let's define a couple things:

In one of your previous emails you specified Site "A" has a
transmitter on 6 meter and a receiver on 2m. Site "B" is the opposite
with a transmitter on 2 meter and a 6 meter receiver. Since you are
using RTCMs you can do everything with one Asterisk/app_rpt server
which can be located at either site, as long as there is an active
network connection between all points.

Ignoring anything Asterisk related, traditionally a system such as
this will normally be configured in one of two ways. Either each
repeater is individual, where 6m and 2m users are not able to talk to
each other, or they are linked together, where a user transmitting on
either the 2m or 6m input will be output on both bands. I did not see
this explicitly specified in previous emails so I will cover both
configurations below.

If setup for the linked configuration, a single RTCM can be used at
each site for a total of 2. The node configuration would consist of a
single node number that uses both RTCMs as voting receivers and
multicast transmitters. Only one receiver can actually receive
anything due to different bands, but the voting process with handle
that. Once the audio is voted it will then be sent out to both
transmitters.

The first way to setup the unlinked configuration is to use four
RTCMs. These would then link back to two separate nodes. This would
allow the ability to link the two repeaters when needed/wanted. Of
course this is what you don't want because of excess RTCMs.

The "new" way that Mike (W5JR) brought up is to configure the sites as
duplex bases. I believe the Cactus Intertie is a network that uses
this configuration. These networks are usually set up as in-band
repeaters, but the receiver audio is linked to the rest of the system
and not repeated through the local transmitter.

This is what I think you are wanting to do. To do so two nodes would
need to be created. One node for the Site "A" RTCM and the second for
the Site "B" RTCM. Then link these through Asterisk. When the A
receiver picks up a signal the audio would be sent back and sent to
the B transmitter. Similarly any signal picked up by the B receiver
would be sent to the A transmitter. Both appearing independent of each
other.

Setting duplex=1 will not repeat the audio from receiver to
transmitter, but uses half duplex operation for simplex nodes. I don't
know how this will function when connected to full duplex radios
instead of a half duplex mobile. Someone else would have to way in on
this aspect.

Hope that helps to clear it up.

Brett
KQ9N