[aprssig] Clarification on Wide 1 digi characteristic please

Keith VE7GDH ve7gdh at rac.ca
Mon Mar 1 15:24:19 EST 2010

Michael N1PLH wrote...

> My APRS call is N1PLH-7 and I am in the zipcode of 06855. I believe
> that I may be able to receive a Wide 2 digi if I were using a mobile or
> base, however, I am only using a portable VX-8DR at the moment and
> I hear the local Wide 1 digi (WX1CT) just fine.

2010-02-28 18:15:20 UTC:

There's at least one digi in your area that responds to WIDE1-1 but that
doesn't do any call-sign substitution... i.e. looking at the above data
I can tell that you went through a WIDE1-1 digi, but it didn't tell us
who it was. You were subsequently gated by WA2GUG-15 with the
WIDE2-1 portion of your path being un-used. The asterisk above tells
us what part of the path had been used.

> I am still just learning how to interpret paths as shown on APRS.fi and on
> my radio. I am not even sure how determine which digis are Wide 1 or 2.
>  I can check for paths that they might be included in and see if there call is
> in the first or second slot, but is that the best way?

2010-02-28 18:47:05 UTC:

As mentioned above, there's a WIDE1-1 involved that doesn't do callsign
substitution, but NA1SV-3 responded to WIDE2-1 and it did tell us who
it was. Again, the asterisk tells us that the WIDE2-1 had been used.
You were subsequently gated by W1SQL-1.

> So, I need to know how I can tell which type of digi is which
> (Wide 1 or 2), and then how I can see if I can hear that particular station
> directly. Or, am I going about this all wrong to try and understand the
> network in my area?

I don't have an 8R, but doesn't it have a "station list" that would tell
you if you heard a station or not? Does it show you the symbol used
by the digis? e.g. a digi symbol with a 2 overlay would indicate that
it would respond to WIDEn-N up to 2 hops... i.e. it wouldn't respond
to longer WIDEn-N paths than WIDE2-2. A digi using a digi symbol
but a "1" (one) overlay would indicate that it was a fill-in digi that
responded to WIDE1-1 only.

You could look at the symbol used by the digi... e.g. NA1SV-3 is using
the digi symbol (star) with an N overlay, indicating that it responds to
WIDEn-N. However...

2010-03-01 11:02:41 UTC:
:!4110.55NN07313.42W#PHG5050 Fill-in Digi in Fairfield, CT

it claims that it is just a fill-in digi. My take on that is that the information
"fill-in digi" is erroneous... basically,the symbols and beacon comments
by digis are supposed to tell you of their capabilities, but not always.

> Another thing, I Gates are nice, but I am a bit of an RF snob and it is too
> bad a couple of the local stations are only I Gates that receive.

I'm not quite sure what an RF snob is. Perhaps you could explain so we
don't go and read something into that statement that isn't true. I'm not sure
what you mean by "a couple of local stations are only I Gates that receive". 
All IGates are supposed to receive. They would be kind of useless without
any receive capability, They are also supposed to gate what they hear to
the APRS-IS. If set up properly, they would also gate messages to RF
for local stations... i.e. if I tried to send an APRS message to you, a local
IGate would gate it to RF if it thought you were "local"... in other words,
IGates should be capable or both receiving and transmitting.

If by "RF snob" you mean you don't want to be gated, just add "RFONLY"
or "NOGATE" to the tail end of your path... i.e. WIDE1-1,WIDE2-2,RFONLY
No guarantee, but most digis would not gate you to the APRS-IS if you do this.

> As I drive through these areas, my radio hears nothing, but my packets
> are making it to the internet only.

There can be many reasons for "not hearing" anything. Maybe no-one is
beaconing in your area. Maybe you're running with just the rubber duck
on the 8R and other stations and digis around you could be a bit distant,
or running low power, or on less than optimal antennas. Maybe you just
need to use an external antenna on the 8R. Maybe there's a problem with
your 8R and your radio is deaf. Options... you could test the radio with
an accurate signal generator, or you cold get together with another 8R
user and see if their receive performance is comparable to yours.

I'm not sure if you have an actual problem, or if you are just in the midst
of learning about APRS.

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

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