Gary grwes...@... wrote:
Maybe there is something that the path simulators are missing.
It could be Gary and I think it's fair to say that propagation
simulators are just not capable of capturing all the variables of the HF
channel. They do, for the most part, capture the fundamental
For ARQ there is an additional criterion, viz. the value to look for is the
thin border
line between 95% and 100% copy. 95% copy is generally not enough for efficient
ARQ operation.
That is why pskmail does not use S/N levels as the only parameter for switching
modes,
additionally we use block
Gary,
Thank you for the feedback. Using ARQ systems like you did we have also noticed
that faster PSK modes show better performance as in less repeat request than
slower ones.
Your first theory is the one we believe is the most likely contributor for the
ARQ links in general benefiting from
Hi Tony,
Thank you for the information. This is the issue with field tests, there are
always several variables.
I will proceed with some other field tests, trying to eliminate some of the
variables. In my case I have an inverted V on 40 and 80M at only 9 meters peak
over the ground for the
I have done several tests with DA5UWG on 80m, and the 200 km path still shows
lots of multipath.
Both antennas are low (mine is a full wave 80m loop at 10m, DA5UWG has a dipole
at 12m).
Sometimes the mode goes up to PSK500 for a few frames, but it always switches
back to PSK500R, PSK250R or
Rein, what is the cause of the 1700hr heaviest multipath? Is that a
ionospheric condition of some peak airport traffic issue ?
Andy K3Uk
On Fri, Apr 2, 2010 at 7:35 AM, Rein Couperus r...@couperus.com wrote:
I have done several tests with DA5UWG on 80m, and the 200 km path still
shows
Your question is one that I have also. In our recent NVIS testing with
fldigi/flarq we found BPSK250 provided better throughput than other modes we
tested, and most notably MFSK32 which we thought would be our safe, robust mode.
This was with a variety of band conditions including strong
On 4/2/2010 5:24 AM, vk2eta wrote:
Hi Tony, Thank you for the information.
My pleasure John, wish I could have helped more. Thank you for your
field tests.
I should be able to safely eliminate ground waves over that distance
(95 miles).
It would also be interesting if you could
Interesting observations John. I can't offer any useful insight, but look
forward to hearing from those that can.
Andy K3UK
--- In digitalradio@yahoogroups.com, vk2eta vk2...@... wrote:
To Tony (K2MO) in particular, but not exclusively:
Following your simulation results on these modes in
