[A-DX] VOA Radiogram, 7-8 May 2016

[Roger]

Am 06.05.2016 um 16:57 schrieb VOA Radiogram:
> Hello friends,
>
>
>
>
> Lately we have been trying to determine why some listeners have less 
> success with Olivia 64-2000 than with MFSK32, even though, in theory, 
> Olivia 64-2000 should be more robust. I suggested that the problem 
> might be related to the bandwidth of the receiver, given that Olivia 
> 64-2000 is 2000 Hz wide.
>
> Christopher <http://drmnainfo.blogspot.com/>, K6FIB, a key adviser to 
> VOA Radiogram, thinks the performance of Olivia is related to the 
> processing power of the PC or the mobile device. Paul in Europe 
> provided evidence of this in his TIVAR Android shoot-out 
> <https://t.co/TqyHn2wlPW>. Other listeners wonder if it could be other 
> components, such as the microphones on Android devices, which would be 
> important if acoustic coupling from the radio to the device is used.


"....thinks the performance of Olivia is related to the processing power 
of the PC or the mobile device"

I can not believe that.
I use a Pentium4- PC from the year 2003.  There has never been problems 
with OLIVIA.
The one and only performance problems caused by the very challenging 
modes in 8PSK.
For that I had used a laptop with a Intel5 - processor.


".....trying to determine why some listeners have less success with 
Olivia 64-2000"

Audio recordings of them would be more useful for analysis.
In addition, a list of affected radio receivers or decoding 
combinations, to detect a failure pattern.




Olivia 64-2000 is the winner in conditions over Multipath
http://www.rhci-online.net/radiogram/VoA_Radiogram_2016-01-23.htm#multipath


Olivia 64-2000  is the winner despite incorrect demodulation (DSB) out 
off the correct frequency (114 Hz offset), with two identical 
interleaved tracks
http://www.rhci-online.net/radiogram/VoA_Radiogram_2016-01-30.htm#sydney



roger