Re: LF: My thoughts on ROS

[Roger Lapthorn <rogerlapthorn@gmail.com>]

Well, I agree with GM4SLV's comments on ROS, although my experience is very limited and RX only so far. I have successfully decoded G0NDB, G4WGT and GM4SLV on 500kHz. 

Like Mal and John, I also found the user friendliness of the software lacking: the array of dials presented is impressive but rather meaningless apart from the one on the left dealing with audio level. The dials may be meaningful to some. I appreciate this is a "one man job" and very credible too, but the UI does seem less user friendly than WSPR for example.

The spots for other bands, are indeed annoying and irrelevant.  I wanted the spots for 500kHz to remain but these disappeared soon after appearing.  When I first fired up the software I had no idea what should happen and there seemed little FAQ data to help understand things.  Did I miss the basic "getting started" user guide? Eventually bleeps happened and signals appeared, but this was more by luck than plan.

Unlike WSPR I am still confused about how several stations can operate at the same in the same sub-band, although this may be my lack of understanding. On 14MHz there seems to be 3 unique channels for ROS, so does this mean on 500kHz there is just one? With WSPR there can be around 200 stations happily co-existing in just 200Hz of band over an hour or so because of time and frequency separation.

In summary, I was pleased to give ROS a successful go the other night (on RX) but I doubt I'll stick with it either.  Like John P-G I'd like to give some other weak signal FSK 2-way communication modes a go on 500 and 136kHz. 

73s
Roger G3XBM

On 2 September 2011 20:51, John P-G <gm4slv@sighthound.demon.co.uk> wrote:

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

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