If you are considering running a Wide Area Digi, we ask that you please take the following information into consideration. Too many Wide Area Digi's in a given area can create problem for the regional and APRS network at large.

1. The first question you need to ask yourself is, where is the nearest Wide Area Digi? Can a moderately equipped home or equiv. station hear and talk to the nearest Wide Area Digi? If this location is well positionedand can fill in the coverage holes and still talk to the nearest Wide Area Digi then the station should be setup to provide Fill-in Digi service.

2. The next question you need to ask is, at what height will this digi run. HAAT in particular will be the deciding factor between a Wide Area Digi and a station that needs to Fill-in Digi to fill in the holes. For Nashville, all Wide Area Digi's are positioned on the top of hills that overlook a wide area of Middle Tennessee. NT4UX-1 is south of Franklin, TN, NT4UX-2 is on Short Mountain, NT4UX-2 is on Blueberry Hill, and W1ARN-1 is on Music Mountain. Thus, any station in the "bowl" of Nashville should not be a Wide Area Digi. It may serve well as a Fill-in Digi though if there are coverage gaps that neither of the three stations in the example can hear. As a general rule of thumb, if the station will not be 100 to 150 feet HAAT then it should not be a Wide Area Digi.

3. What are the brains behind the setup? We suggest either a KPC3 with V.8.2 firmware or KPC3+ TNC with the latest firmware available from Kantronics or a TNC2 clone. With the TNC2 clones, we suggest using the UIDIGI firmware. The advantages of UIDIGI is removing un-needed TNC2 features, recovery after power failure (does not rely on the battery to retain settings), and features that pertain to APRS. If your TNC cannot provide callsign replacment and support the New n-N Paradigm then it should not be a Wide Area Digi. All Digi's covering the Nashville area support this protocol.

4. What is the braun behind the setup? Wide Area Digi's should be able to talk about the same distance it can hear. Thus, Wide Area Digi radios should be at a minimum 15-20 watts and no more than 50. There may be specific reasons to go above that figure, but a Wide Area Digi should not be less than 15-20 watts. This does not take into account ERP from various antenna designs.

5. Coordinate with existing Wide Area Digi owners and operators. This is important. They may have suggestions for configuration and likewise have reasons why specific areas are not covered. By coordinating with them they can assist to make sure that the problems you're seeing are taken care of and likewise not create or inject additional problems into an APRS network.

Here are some suggestions:

If you are running a fixed station (which can either be a Fill-in Digi or Wide Area Digi) you should not have WIDE1-1 in your UNPROTO path. A WIDE2-2 should be more than enough for local tactical communications that APRS was designed for. WIDE2-2 should be enough to make it to an Igate and get into the APRS-IS system.

With the way Nashvilleaprs.net has structured the Igate system, Wide Area Digi's should only really need a WIDE2-1 or WIDE2-2 statement in their UNPROTO path to make it to aprs.net, Findu and other APRS internet services. Nashvilleaprs.net is attempting to tie together several geographically dispersed igates and have them all feed into one of three geographically dispersed "HUB" systems which then tie into the national aprs.net system. Thus, all Wide Area Digi's should easily be gated with an UNPROTO path such as WIDE2-2

It is suggested that if you you are running an Igate then it should only have an alias of WIDE1-1 and serve as a Fill-in Digi. A Wide Area Digi should be reserved for full time digis on relatively high terrain running 24/7. With the technology today a Wide Area Digi should support the New n-N Paradigm. If someone has a a good place to put a Wide Area Digi and has a TNC2 clone I would be happy to program a UIdigi ROM for them.

There is a need for Fill-in Digi stations. Most fixed home stations in the area can hit one or more of the NT4UX-x or W1ARN-1 digis directly. If so it doesn't need to be a Wide Area Digi but would be very helpful to mobiles as a Fill-in Digi.

Suggested configuration information for a digi in the Nashville / Mid-TN region:

UNPROTO WIDE2-1

UNPROTO WIDE2-2

Please note that anything wider than 2-2 creates additional unnecessary traffic on the APRS network. Futhermore, it accomplishs very little other than to announce where your digi is to places that may in fact not care about your digi.