Thank you for that explanation. I didn't know the modulation mode would
make
a difference. It would have been interesting to test the theory with Skip.
Unfortunately, we live too far apart for VHF/FM.
Thanks again...
Tony - K2MO
Tony,
You do not need to test only with me! You can test
As more people try using digital modes on 2 meter FM, the overall best
performing mode will automatically surface, but for the longest
range on
digital modes (not counting CW), it is really necessary to use SSB,
and in
that case, we have found that MFSK16 is just too critical for tuning
to
someone else with the same setup, but that should become easier to do as
time goes on.
73, Skip KH6TY
- Original Message -
From: Vojtech Bubnik bubn...@seznam.cz
To: digitalradio@yahoogroups.com
Sent: Monday, February 23, 2009 1:02 PM
Subject: [digitalradio] Re: NBEMS QST article/digital
Hi Tony,
The original reason we went to DominoEx instead of MFSK16 or PSK63 was
because at VHF (we were originally using SSB), transceiver drift, in
addition to multipath, is a major problem and MFSK16 is much more critical
for mistuning or drift (on SSB) than DominoEx. But, when using FM,
Hi Tony.
I suppose the reason is that we are comparing MFSK16/DominoEX over FM
versus MFSK16/DominoEX over SSB. I believe they are just different
animals. SSB only shifts signals in frequency. FM does much more
complex (in mathematical sense) transformation.
Skip is doing interesting pioneering
Hi Vojtech,
Thanks for the tip. I totally forgot about the possible effect of deemphasis
and what effect the center audio frequency might have.
Our goal with NBEMS has always been able to reach at least 100 miles
reliably, in order to span the largest expected disaster area to reach
Internet
bubn...@seznam.cz
To: digitalradio@yahoogroups.com
Sent: Sunday, February 22, 2009 7:53 AM
Subject: [digitalradio] Re: NBEMS QST article/digital weak signal FM
Hi Tony.
I suppose the reason is that we are comparing MFSK16/DominoEX over FM
versus MFSK16/DominoEX over SSB. I believe they are just
as it is on on SSB/CW satellites.
Just a thought...
Tony - K2MO
- Original Message -
From: kh6ty kh...@comcast.net
To: digitalradio@yahoogroups.com
Sent: Sunday, February 22, 2009 8:58 AM
Subject: [digitalradio] Re: NBEMS QST article/digital weak signal FM
Hi Vojtech,
Thanks
