[aprssig] Re: Fill-in Digis

[John Ronan]

On 24 Mar 2006, at 22:23, Robert Bruninga wrote:

> Regarding Mobiles hearing digis better than getting
> in due to the DIGI's high site vulnerability to QRM:
>
>> What we have experienced is exactly the opposite,
>> I can get into the  Digi, but not be able to decode
>> the forwarded on packet (can hear it/ see the S meter
>> rise though).
>
> There are two very common reasons for that:
>
> 1) THe digi audio was never properly set up, so that the
> tones are properly balanced, or the digi has too much
> de-emphasis..
>
> 2) If  two digis hear your mobile, both will digipeat it
> as they should, and quite often you will "see"
> a collision and not decode it.  This is normal.
> It does not mean that you are not hearing the digi.
> You will still hear packets coming in from one digi
> or the other, just not at the same time.  Also
> anyone else near either digi will hear you fine too.
>
I was talking about the mobile scenario, as all my APRS kit at home  
is generally listening for PCSAT/PCSAT2.  Strangely enough, most of  
the time on the roads around here, one tends to hit one digi or  
another, but not more than one at the time.


I've to drive to my folks place tomorrow, and I know I'll be going  
out of digi coverage, purely out of interest, I'll digi every minute  
and see what the results are like.

Have a great weekend folks.

de John
EI7IG
--
John Ronan <jronan at tssg.org>, +353-51-302938
Telecommunications Software &  Systems Group,  http://www.tssg.org