Aaron:

While we are all learning, I disagree from the posts that you have a packet
loss problem.  The W6YYY system has been having measurable packet loss
problems (from zero to 40%) in bursts - the effect of ISP packet loss on
dstar audio is not the garble you are hearing, but missed words, syllables -
basically, a very choppy, jittery sound.  Entire words will be missed, then
the audio will appear fine.  ISP packet loss does not seem to cause what I
was hearing on the recording.

Your recorded audio indicates that the voice error correction in the voice
coder is unable to correct all the errors.  Usually this is an RF problem,
but you specifically said it occurs during gateway and reflector operation.
So my conclusion is to use tools that can determine error rates as opposed
to packet loss.   I cannot suggest tool for this.

Also heard was the common 4-5 second period of garble, then recovery.  This
is usually an RF problem, not ISP.  This phenomena is common to the design
of the VHF and UHF repeater receivers - its is almost like a tight squelch
problem.  I thought this was just a digital characteristic, but then I
listened to 1.2 GHz repeaters, and these users gracefully start distorting,
recover, etc. when they are weak.  No 4-5 second dropouts.

Try this: Have a strong user access the repeater, then disconnect the
receiver antenna line in the middle of the message.  The repeater
transmitter will transmit 4-5 seconds of garble, then drop out.

If you disconnect it for only a second or two, then reconnect, the user will
still be garbled for the same duration, then recover.  The same thing will
occur if another stronger user, or stronger interference (IX) covers the
desired signal.

So I am saying that some of the recordings were just weak RF, or IX issues;
the others were different.


Greg Forrest
N6LDJ

W6YYY/W6UUU Trustee
440.0375 +5MHz Voice (Oakland, CA)
444.0375 +5MHz Voice (Pleasanton "Garage", CA)
925-337-4444
[EMAIL PROTECTED]


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