O P E R A is (should be) a Beacon only Mode

ROS OPERA digital radio data mode at 200uW ERP is still performing well here, G1OPS at 135km distant received me earlier today.
I often hear Chris G3XIZ on the Key when I am testing OPERA, I thought that it would be possible to work cross mode. With my PIC system I can input anything I like all be it a bit of a task and it must not be rejected by Jose as a non call sign.

I put the idea to Chris and he downloaded OPERA, within minutes I spotted that he had seen me, OPERA chat is useful, In exactly 30 minutes we had completed a QSO. A but irregular for the mode, a bit like M/S and good fun.

This was my transmission with a 13WPM Morse ident before each.

17:02 500 RR5RRR Op4 +7 dB
16:57 500 G3XIZ Op4 +6 dB 46 km @ 120
16:49 500 R5SIG Op4 +5 dB
16:43 500 G3XIZ Op4 +7 dB 46 km @ 120
16:38 500 G3ZJO Op4 +7 dB 0 km @ 000
16:32 500 G3ZJO Op4 -16 dB 0 km @ 000

Chris’ Morse transmission was more verbose but his hand is so good I could type my comments on how it was going and the next proposed step in OPERA Chat and read him at the same time. A bit of a 3 way even, via the web although it was not internet assisted we knew the procedure we were going to use. Chris did not know what form the reporting messages were going to take.

An evening at the OPERA (OPERA Radio Mode)

I have waited for the TX experience of ROS OPERA digital radio data mode until I had my QRPp home built PIC controlled TX running. Yesterday evening I ran OP4 on 500kHz, the TX produces less than 200uW ERP from my antenna which is now a simple inverted L 5m up 5m out.

The TX was built for QRSS FSK so I had to modify it to run A1A on off keying although I have proved that OPERA does not mind being sent as FSK. The TX had been running on QRS3 and QRS10 on 500kHz with zero reports. I therefore was not expecting much in the way of results.

But results we got, very impressive.

My PIC Code sends selectable OPERA Speeds/Modes followed by 12WPM Morse ident, it is simplistic and like my WSPR PIC Code, written only for my call sign so please don’t ask for a copy. G4JNT has produced a sophisticated multi user code for both OPERA and WSPR which are available for download.

The ROS/Opera software is still in its Beta versions, the CPU load is very high which tends to put me off. No problem for me if I don’t want to receive too, everyone else uses oodles of computer power to receive me.

OPERA New Data Mode 7 Days on

ROS OPERA digital radio data mode was launched at the beginning of the year (2012). Using single frequency on/off keying it is about as basic as a Digi Mode can get. Resembling Morse Code which was designed for manual de coding, OPERA is designed for computer de coding. It was particularly developed and is suited for LF propagation and communication using slow data rates. Initially it is a Beacon mode sending Call Sign only. The Data is sent at different speeds giving rise to Op2 Op8 etc, these are not different modes, Op2 sends in 2 minute time frame Op8 takes 8 minutes.
There is data repetition on TX and FEC in the decoding I believe, which enables performance well down into the noise level.

I tried it on the first day and had good results, I have held fire on commenting mainly due to the Soap Opera which followed the release of ROS from the same software author. Could this have had an influence on the choice of name for the new mode.

OPERA has not been immune to the same sort of problems and criticisms. One source of dismay for some is the amount of web connection that installs with the software. Well learn to live with it, the facilities it provides are useful and suited to the mode which is from EA5HVK, Jose Alberto Nieto Ros so what did you expect.

If you don’t like being connected to the web facilities, turn off your modem and you will never be bothered by spammers, or rude people on forums either. However you will be left a bit in the dark.

Processor and memory use is high. Even to the extent that AVG warns of excessive memory use by Firefox when running OPERA. In my world the best software is elegant and puts the least load on the system. Does this simple mode really need more processor power than running 3 simultaneous versions of SpectrumLab. When writing software I always remember Neville G4CPY and his standard line “WHAT your program resides in more than 1K of memory, your code is not very efficient”. He was always right too.

Another problem is frequency choice and clarity of operation. OPERA does not want to be among the CW stations, well only if you want bile from them. Some operators need to be told where to set the dial too which has caused problems.
My main improvement would be related this, already many users including me have moved today to Dial 503kHz on 600m to avoid the CW region. If only the drop down frequency box said Dial XXXHz Transmit XXXHz to XXXHz instead of leaving operators to do the complex maths of Dial = mean(frTX High,frTX Low)- 1500Hz, surely we don’t expect operators to know what they are doing, or to be able to count.

It would be very good to have at least the parameters of the TX data released once all is settled (there have been several changes since release) so that a simple computer-less beacon can be programmed like we do with WSPR. Many Hams are avidly against secret coding.

EDIT :- Next day our wish has come true, apparently the new version will output the TX Code.
However frustration, the download link doesn’t work, maybe more mods in the pipeline.

Finally how can we be sure that this single keyed carrier (yet agile) frequency is not spread spectrum and furthermore what ever is the bandwidth of this new mode :DD

In this capture of a couple of nights ago on 500kHz my stations received on a very poor antenna are shown on the left other reports via the web are on the right.

Note:- 1) I don’t use the Waterfall on my XP SP3 machine to save processor load as I run SpectrumLab to my LF Grabber.

Satellite Tracking with the Meteor set up.

As promised the first satellite pass I have seen since yesterday, this one was this afternoon.
Starting with possibility of it being the biggest reflector around I checked the ISS position. At first dismissing the possibility as the track was over the sea. Giving it a little more thought and examining the capture and the track it seems likely not to have been the Space Station.

The ISS track was from West of Ireland across the Atlantic to the North coast of Spain. In the 3D capture North would be on the left at the Time Line and South opposite. GRAVES sits at 1000 on the frequency line. The reflection gets better from the North as it approaches 90 Degrees to GRAVES and grows steadily as it heads South gradually being illuminated more by the signal but moving further away. However the Doppler shift does not fit in with that.

I shall watch the orbit predictions for ISS and be waiting for it in the future.

This one later does fit the bill for a Satellite orbit travelling North to South which is the norm, I watched it live too. Checking the orbits, it wasn’t ISS.

At 22:56:00 there is an indicator of the signal source, time stands still on the Satellite track briefly. GRAVES switches phase and so the beam heading of its antenna array making it a slightly imperfect signal for meteor reflections, I believe the ‘glitch’ is the switching.

Edit 2017 I have been trying this again recently, the ISS can be too high for the GRAVES beam on some close orbits I do get track which coincide with ISS passes, often tracks are of Satellites there are so many that it is difficult to identify which.

G3ZJO Meteor Grabber

So yesterday we set up a Meteor Grabber using the signal from the GRAVES Transmitter in France, after some calibration this morning it is giving very good results.

The transmitter located near Dijon in France runs high power on 143.050MHz and is installed for the purpose of Radar Tracking of Orbital Satellites, It is therefore ideal to use for the illumination of Meteors. I can clearly see the phase switching of the direct signal off the rear of its beam pattern using my 2m beam, using a Co-Linear antenna the direct signal shows as an occasional trace.

The distance from my location to GRAVES is 715.525km, the beam pattern is a 180deg arc to the south as indicated by the yellow circle.

The site is a decommissioned air field, the antenna array can be seen on Google Earth.

Despite the lack of any pronounced Meteor Showers at this time, monitoring has been very interesting. There was a track of a Space Craft which I didn’t capture as it took me by surprise and I was not sure of the origin, I will post a Grab as soon as I get another.

Meanwhile the best Meteor to date was this one which gave multiple reflections, after the initial ping, which sounded like a bell ringing.

Here in the 3D trace.

Here in the conventional 2D Time Horizontal, Frequency Vertical display.

I will try and run the Grabber as much as possible particularly for the Quadrantids showers expected around the 4th January, these Meteorites come from a now extinct Galaxy.

The equipment used is:-

Antenna – Diamond Tri Band Co-Linear
Receiver – Yaesu FT897
Computer – Samsung N10 Netbook
Software – Spectrumlab