JT2 Two Way Contact Made

Computer problems in France have caused delays in experiments with JT2 Mode. My signals were decoded and replied to by an anonymous commenter who it seems considered that we were running the ‘WRONG MODE’. I know what he meant, I was testing on my beacon frequency on 10.140070 ‘ish. Beaconing with a mode that can be replied to could attract fools who will reply, and he did.

The Laptop which I delivered two years ago to France refuses to decode any JT2 signals. Today the Tower Computer was pressed into duty and reports were exchanged. F6GUU carried out local tests from one machine to the other last night, always a good idea with a new mode I feel. He proved the Laptop system works one way but not the other.

 

If you try new modes with a local station you need someone with trusted equipment and reliable knowledge base of techniques. Too many times I have been told that my signal is no good and cannot be decoded by someone who has not set up his own station properly.

One only has to view the ‘slant merchants’ on SSTV. Transmitting slanted signals and telling incoming stations that its them that have a slant.

SDR Video using Winrad

Winrad software presents an extra problem for producing screen captures. Don’t worry your one eyed, one legged, aged technician has conquered both that and getting the program to run in the first place.

Winrad versions are built to expire and be replaced. If you try to run a version after the sell by date you click on START and it dies. I installed a new version and what did it do, just as described. Now if your computer date was wrong when you started the program you would get this, my date was correct.
I have run previous versions and it is a superb piece of software so I was a little peeved.
I run software on XP under two accounts one with full privileges one without, it would not run on either. I may have done my first run without admin privileges, did this cause the problem, maybe. The cure for running with the wrong date is to download and re install the latest version as a last resort, I tried it, it worked.

It is a pity the definition of the software defined radio video is not a bit better once it has been YouTubed. The display of several different Data Modes in the bottom window is superb. Here we also look at SSB too.

Sorry it is short I have to keep the file size down.

Next Morse code, I change the LSB filter to CW and re position the filter curve on the signal.

Again short but I hope sweet.

Sound Cards compared using Winrad

Winrad software is superb for analysing signals over a wide and narrow band width.

Comparing the background noise on my Dual Core high spec. Laptop which has a Realtek HD Sound card with no audio input.

With my Celeron processor desktop with Delta44 Sound Card set up exactly the same.

Speaks for itself ………….. literally.

Yes there is a volume difference due to my recording process on 2 different set ups. On the second one there is a much louder nothing.

QRSS Peace to all

Very much in the spirit of Amateur Radio an international symbol of peace accompanies the beacons and my JT2 signal today.

For those who know not of the antics of radio the Blue background is a small portion of the Radio Spectrum. The White dots are Noise. The Dove is a signal switched on and off and moved up and down to literally write in the Noise.

A little later and here is my signal less than 1Watt power into Australia.

JT2 Mode from the WSJT stable

Having been away for a week I could not wait to get on with the new mode JT2.

Ideal for weak signal work on HF, the bandwidth (as long as you do not send a Morse Ident) is only 8.75Hz.

Some QRSS Knights have been testing the mode, I have seen no contacts reported so it was time for a CQ call or 1000.

Using 5 Watts in the afternoon I could see my signal in the Netherlands, Belgium, UK, Singapore and Canada.

I dropped power to 0.7W and still was fine into Canada as the capture shows. All I need is someone set up for the mode at the other end and we should have communication.

The 3 postage stamps near the top of the display are my minute long bursts of data.

Old Fashioned Morse Code

The Government stations have ceased Morse Code transmissions, there is no need for a test to obtain an Amateur Licence. Morse Code must be a dead mode.
Not a bit, Morse Code is a Digital mode, having only three states it is reliable and can get through when other modes fail. Given the processing power of the human brain, as seen in the previous post, decoding can take place which a machine cannot do.

But surely it is slow. Well take a look at this.

Morse Code de coding with SDR

The next ‘can we do it on one computer’ is Morse decoding. I used the second sound card to feed audio from the Softrock TX/RX v6.1/Rocky combination to CWget software.

Machine decoding can’t cope with sloppy sending like the human ear can. Operators invariably slur their own call signs. I didn’t use one example decode because of this, although I could read his call sent at 30 words per minute as GM3XXX CWget persistently printed G(–…–)XXX in other words G(7 char symbol unrecognised)XXX.
Examining the waveform that CWget was presented with proved that it was indeed being fed –…– instead of — …– machines are unforgiving.

PSK31 with KGKSDR

By feeding the audio output from the Software Defined Radio into a second (or third) sound card and using BPSK decode software such as Digipan (tested) and WinPSK shown here, KGKSDR which does not have a PSK31 decoder built in can be used for the mode.
Transmit? well that is another thing.

KGKSDR CW contest

A slow tune through the many stations at the CW end of 40m during the contest on 3rd Nov 2007 using a LSB filter 2.1Khz wide.

The colour scheme of KGKSDR is a custom one I have set up.

KGKSDR SSB on 40m

KGKSDR is very configurable, using the Old Scope colour scheme I take a look with the Softrock TX/RX v6.1 at the SSB contest stations on air on the 3rd Nov 2007.

Toward the end of the video a signal is seen to sweep to and fro across the band. It was quite persistent, I think it may be a station with his rig on tune swinging his VFO.