Date: Fri, 2 Sep 2011 19:51:39 +0000 (GMT Standard Time)
From: John P-G <gm4slv@sighthound.demon.co.uk>
To: rsgb_lf_group@blacksheep.org
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Subject: LF: My thoughts on ROS
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LF,

One of my objectives listed on my application for a NoV for 500kHz was to 
assist other UK stations in their own experiments, acting as remote eyes 
and ears, and it was in this role that I accepted Graham's request to join 
him and others using ROS.

The mode has had a huge amount of press - negative and positive - and 
being a one-person development (and closed source) is certain to be 
controversial.

After installing the software on my NetBook (Samsung NC10 - the only 
Windows PC I had available) I was initially bewildered by the look, feel 
and configuration of the beast. 

The continuous appearance of information relating to bands quite unrelated 
to the band you've selected is annoying and, on the small screen of a 
NetBook, very distracting - taking up valuable window space.

The MF mode, with it's 2 symbol rates, is nicely compact, in 100Hz 
bandwidth, and the modem seems very sensitive - often (on a quiet band) 
giving 100% copy of signals that were inaudible in the speaker and 
invisible on a separate RX/waterfall (the netbook screen is too small to 
allow me to use the ROS waterfall). 

In the presence of lightning static crashes I found it less sensitive, 
often failing to lock on weak signals, but coping only with those that 
were both audible and visible.

As a QSO mode - yes it probably does very well, but the user interface is 
awful - little documentation to get the casual user started - and the 
continuously and pointless spots of other bands is enough to drive one to 
distraction - and there is no way of storing a sequence of spots on the 
band you're operating on, which means you can't easily digest just who has 
reported your last transmission before it disappears, replaced by a spot 
on 50MHz...

I am always interested in digimodes for QSOs, not just for beacons, but 
ROS falls short, I'm afraid.

Mal's reported problems with both ROS and WSPR decodes failing might be 
more a problem with his computer - as most people manage to decode WSPR 
signals from the very weakest (just visible) at -30dB up to the very 
strongest (bright white trace) at +10dB or more. Failure on stronger 
signals is generally a timing issue - soundcard sample rate errors - and 
failure to decode in general is a PC clock timing issue - the PC /MUST/ be 
synchronised to UTC - via NTP/Dimension 4 or whatever. Window's own 
inbuilt "network time sync" just isn't good enough.


Now - anyone want to try some other datamode (FSK only, Class-E amp) tests 
this weekend?

For tonight I've got a CW beacon running on 501.5kHz but would be happy to 
try a CW QSO if anyone hears me. Can't do x-band - no HF antenna....

Regards,

John 
GM4SLV