Tony,
Our on-air tests show that ROS 16 baud, 2200 Hz wide spread spectrum was
very poor on UHF under Doppler spreading. Can you confirm this with
flutter tests like Jaak has done on
http://contestia.blogspot.com/p/pathsim_09.html ?
73, Skip KH6TY
On 7/19/2010 9:42 PM, Tony wrote:
All,
With all the attention ROS has been getting lately, I thought it would
be interesting to see how the narrow mode compared to the wide version
under the controlled environment of the HF path simulator. After a few
hours of testing, it seems there's little difference between the two.
The simulator indicated that they both had the same sensitivity
(-15db) and essentially the same poor channel performance
characteristics (see throughput samples below). In no case did one
mode outperform the other to the point where it would make any real
difference; both have the essentially the same wpm rate as well.
These tests are not conclusive, but they do suggest that there may not
be any real advantage in using the wide mode vs narrow under most
circumstances. Of course, the simulator can only emulate the basic
characteristics of the real HF channel so it would be interesting to
hear from those who have compared the two on-air.
Tony -K2MO
____________________________________________________________
CCIR-520-2 POOR CHANNEL SIMULATIONS: -11DB SNR
ROS 2250 / 16 baud
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Lghe quick brown fox jumps over the lazy dog
the quccirown fox jumps over the lazy dog
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ROS 500 / 16 baud
the quick brown fox jumps over the lazy dog
the quick brown fox jumps over the lazy dog
the quick breFn fox juo3s over tes lazy dog
the quæe t ´uls r?umps over the lazy dog
the quick brown fox jumps over the lazy dog
the quick brown f Á jumps over the lazy dog
the quick brown fox jumps over the lazy dogQo
