[aprssig] Dirty signals vs. hardware TNCs

Brian D Heaton ky9k-lists at ky9k.org
Wed May 11 15:53:58 CDT 2016

On 5/11/2016 12:13, spam8mybrain via aprssig wrote:
> What is the solution to this problem?  Do we "reward" the users with 
> poor quality signals by using a digipeater with a soft-TNC that can 
> pull their packets out of their distorted signals and retransmit them 
> clean, or do we use hardware TNCs that will reject their signals as 
> QRM and keep them from propagating? Unfortunately, the soft-TNCs do 
> not report the signal quality associated with a packet, such that a 
> digipeater operator could inform those stations that they have lousy 
> signals (and who knows if those stations are listening or contactable?).

If they don't see their packets being digipeated, some (possibly large) 
percentage of hams will attempt to correct the behavior by cranking any 
and all available knobs to "more." Intentionally silently dropping 
over-deviated packets isn't likely to help fix problems.

Direwolf has the option to log packets to a file with daily rotation. 
That file can be easily postprocessed to reflect packets received with 
an audio level higher or lower than a specified range. The error count 
per packet is there as well if you're running Direwolf with FIX_BITS 
turned on. To help operators get their deviation set correctly, 
postprocess the file dumping out statistics on stations outside the 
appropriate receive audio level, pull the file daily/weekly/whateverly, 
and contact stations as desired to attempt to help them set audio levels 


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