R Ed,
There should not be any Doppler
problems as Op only has a single tone and
is not trying to determine frequency shift,
more likely to be loss of data past the
50/55% ?
Its not the decode level that I am
looking for , its the number of
decodes at range in a given time period , the
maximum data rate is limited by the CW
keying speed of a TX, what's the
minimum 'dot' width that can be produced ,
from say 50% power points ?
Look out for the 2/4 500 test from the
usa , that should give an indication of
the cycle time / s/n play off
73 -G.
Sent: Saturday, February 11, 2012 12:15 PM
Subject: Re: LF: WE2XGR/6 OP8 & OP4 tests
Hi Graham
I am far from anti, would just like to see some
proof with my own eyes, with an hour between mode changes propagation can of
course be totally different.
From my example below within 1 minute of
each other OP8 will look as if it is doing better.
17:32 500 G3ZJO de G4MDH Op4 104 km -26 dB in Wootton
Bassett with 0.0002w + 5m inv.L - rx
17:27 500 G3ZJO de
G4MDH Op8 104 km -33 dB in Wootton Bassett with 0.0002w + 5m inv.L - rx
Trouble is I was testing on 50MHz last night and saw the same results
OP2 failed to decode more often than OP1.
Here are the first 6 transmissions
when there was little Aircraft activity.
21:50 50700 G3ZJO de G6AVK Op1 127
km -10 dB in Essex with 0.5w + 4element at 5.5m agl
21:49 50700 G3ZJO de
G6AVK Op1 127 km -12 dB in Essex with 0.5w + 4element at 5.5m agl
21:47 50700
G3ZJO de G6AVK Op1 127 km -13 dB in Essex with 0.5w + 4element at 5.5m
agl
21:46 50700 G3ZJO de G6AVK Op2 127 km -17 dB in Essex with 0.5w +
4element at 5.5m agl
21:44 50700 G3ZJO de G6AVK Op2 127 km -16 dB in Essex
with 0.5w + 4element at 5.5m agl
21:40 50700 G3ZJO de G6AVK Op2 127 km -25 dB
in Essex with 0.5w + 4element at 5.5m agl
When there is the chance of
Aircraft enhancement OPERA seems pretty robust Doppler causing only
rare problems. Most often, with power levels set for no direct path
decodes, both OP1 and OP2 'hop on to Easy Jet for a ride'.
22:32 50700
G3ZJO de G6AVK Op1 127 km -8 dB in Essex with 0.5w + 4element at 5.5m
agl
22:31 50700 G3ZJO de G6AVK Op2 127 km -6 dB in Essex with 0.5w + 4element
at 5.5m agl
We still have to try both stations beaming to Flight Path Hot
Spots to try parallel Doppler when there in no chance of direct decode but I
think OPERA will do it.
Yes some of this mail is O/T for LF.
Eddie
G3ZJO
On 11/02/2012 00:29, Graham wrote:
Interesting post in the yahoo group
May be a long haul OP2 test
would give a useful comparison , other than ground
wave , I have not seen , the longer OP16
produce reliable decodes on 500 , OP8 may
be the better choice , but 2/4 have not
been tested ?
G.
WE2XGR/6 [aka WE6XGR-OPERA mode call sign] I ran OP8 for an hour and went
to OP4 for an hour and back to OP8 for final hour. OP8 certainly shows promise
as a good compromise speed. On OP8 many decodes were all the way down to -35
[G0KTN]. Best I got on OP4 tonite was a -30. All transmitting tonight was at
200 W and that is 20 W ERP with my antenna.
> Thanks to the following
for all the decodes;
>
> G4WGT
> G0KTN [-35 USING
OP8]
> WU9Q
> WW2R
> AC4IU
> W3NF
>
N4FRE
> K3SIW
> N6RY
>
VE4XC
