Weather fax on netbook + portable sony radio

[iainhu]

Results from Eton radio on transAtlantic crossing

Well after a lot of activity at the end of last year in the run-up to the ARC 2011, I promised to 'report back' on my success with the Eton radio and collecting weatherfax during the ARC crossing.

Well, it's not good news I'm afraid; I couldn’t pick up *anything*. I believe my problems were down to the boat which had on-board AC, two fridges and a freezer running and so I suspect simply too much RF interference. I'd expected my initial problems while in Las Palmas to disappear once we got to sea, but it wasn't to be.

Now I could have powered-off the inverter and shut-down the fridges and freezer, however, it seemed a bit of a risk to power everything off simply so I could 'experiment' with weatherfax when we could already collect gribs and other weather data from the Internet via sat-phone. If something didn’t restart properly it would jeopardise the trip and so my decision was to forego my ‘hoped-for’ weatherfax reception and leave things alone.

The boat also had an on-board SSB, however, it wasn’t possible (for various reasons I’ll no go into here) to plug in and receive via that and indeed I couldn’t even get an audio signal via the ICOM 801 from either Boston or St Louis much less attempt to capture and decode it. So sadly all a bit of a disappointment. My hope now is to try on a delivery of a much simpler yacht, e.g. no a/c, simple 12v fridge) from France out to Greece…so maybe I’ll have something to report back after that trip.

For anyone interested, there’s a short video of the ARC trip (although excuse the ‘private jokes’ embedded in it!)

 

[oldvarnish]

I confess to not having read every page of this growing thread so apologies if this has been mentioned: an App for the iPhone called HF weather fax.

I have yet to try it, but if it works as described you simply launch it and hold the phone in front of the radio speaker from which is coming the warbling.

A weather fax appears on your phone. I think it was only a couple of quid.

 

[iainhu]

iPhone ap

I've heard of people doing this with a laptop and the laptop's mic simply picking up the audio and going from that. Sounds a great idea and I guess would work on iPad which would give a slightly better chance to review the chart. But amazing what you can get to do with a smart phone...

 

[ffiill]

Well at moment I have my Eton G3 Globe Traveler set up at home on an external horizontal wire aerial of about 40 foot.My lap top is fitted up with JVcom 32 fed by 75 ohm coax from the aerial strung beween two ends of my cottage roof.The audio feed to the laptop is high quality sheilded digital quality cable as reccomended by JVcom.
I have no direct line of sight communications as I am surrounded by mountains.
The laptop a 10 year old Thinkpad A20M which cost me £10 on ebay for want of a csmos battery!
I can receive good quality RTTY reception from The German met office in Hamburg for the Atlantic and Med and as far south as The Azores.
Most of the time I can receive their Weatherfax transmissions as well as those of Northwood.
However due to it being a bounced signal it is often dirty and last night was the first time I got a clean picture but just to be akward the programme didnt centre the image at the beginning of the transmission.Although JVcom allows you to cut and paste saved images and sort out such problems.
Whats the point-well mountains dont get in the way of bounced images and for me a good synoptic chart is just like any other chart instantly telling me what the weather is doing.
Likewise RTTY buoy;ship and fixed station reports are meaningfull.Nothing like knowing how high the waves were on a buoy in the Irish Sea an hour earlier or how strong the wind is at Stornoway Airport.

 

[ffiill]

These are more results taken from earlier this evening. At the beginning you can see some 'experiments' with and without the external aerial. The results aren’t as good as earlier and you can see periods of ‘frequency tuning’ often making things worse, at one point even turning the plots into reverse (white lines on black). This was all from tuning the signal and nothing to do with program settings!

One of the main problem seemed to be ‘skipped lines’ where every 5 or so lines, there would be a white ‘missed line’. I also found that while the signal was stronger using the external aerial, with the built-in aerial the charts were darker but less broken. Which though is better? All to be decided as you are trying to receive charts for use…

All three sets of charts were collected simultaneously, so this is with the exact same feed into the one laptop although of course maybe not all programs are setup ideally. SeaTTY for instance includes a squelch control although I’ve not yet been able to use it to any visible good effect.

The main characteristics of the charts seem to be:

• jvComm seems to give the ‘dirtiest’ charts – a lot of ‘black noise’ making the charts hard to interpret
• Mscan in some ways is the clearest but suffers for black horizontal banding and the extremely irritating ‘Unregistered’ banner. A note to the software author…this kind of ‘demo software’ makes me inclined NOT to purchase a license as I can’t properly test the software. Maybe you should think again about the means of restricting your demo copies?
• SeaTTY produced lighter charts and still tends to be my favourite

I have reduced the imagesfrom 1,810 pixels to 1,000px wide and in the case of the Mscan saved as jpeg. This to try and fit on a screen and be read reasonably!

From jvComm

From Mscan

And finally from SeaTTY

More experimentation required and comments/suggestions/ideas welcomed

Those are really poor quality-thought I wasnt doing very well on my EtonG3 but despite bounced signal with source about 500 miles away/Hamburg for German charts much better quality than these.
using JVcom.
Appears to be a great deal of interference-are you plugged into mains? because certainly where I live(and I suspect the solar storm )there is a lot of interfernce being picked up by our overhead power lines.
Eton told me that this can be an issue with mains power sources.
Try radio on internal batteries/12v supply if not doing so.

 

[ffiill]

Well here are some of mine-the last of wind vectors just now is rubbish.
Not sure why my pics have reduced in size!-slants need correcting I know.
Shielded lead cost £2 on e bay.
Once back on boat at Arisaig will set aerial up to masthead-I just use 4 strand copper normally used for wiring ceiling spots-tough enough to self support and cheap enough to buy.
Used a similar wire to great effect with my old Homer Heron on my old boat.Back in 90s before its demise I could pick up Decca beacons and aero beacons in Britanny from Rothesay Harbour.

 

[iainhu]

Was I on mains?

No, entirely battery. Interference from the mains kills the charts, but these are early experiments, see post 66 for something a little cleaner.

However, you aerial arrangements sound pretty impressive...40', high quality shielded lead etc. I was using my Eton G3 with a Sangean retractable antenna similar to (but not the same as) this one: www.amazon.co.uk/Nevada-AN-05-Retractable-Clip-On-Antenna/dp/B005I4FYDQ/

So I ended up getting readable results...after much trial and error...just then failed to collect *anything* while transAtlantic, which was a real disappointment.

 

[ffiill]

German weather service Hamburg-650 miles
Today 7.43 UHT 7800 khz
Surface chart
The slight fuzzy bands are where signal drifted during transmission corrected by fine tuning signal until peak is above white spectrum on JVcom
Origional picture size about 24 inches by 20 inches.
Image has been rotated 90 degrees as delivered east through to west.

 

[Conachair]

...just then failed to collect *anything* while transAtlantic, which was a real disappointment.

My 12v fridge was a real killer. And so easy for forget to turn in on again I'll be fitting a flashing LED or something to show it's off for the next trip, even postits on the keyboard are ignorable!

On the way over from Cape Verde to Brazil I had sat phone but no decent ssb reciever so not sure what the reception is like down the canaries / carib route.
Slight aside but I found Gribs fell apart down near the ITCZ. I remember coming up from Suriname getting weatherfax from the web to see what the itcz was up to, gribs didn't show it very well at all.

 

[ffiill]

Having now had several weeks of practise in good conditions I can now set up JVcom running with my Eton G3 using my fine tuning to set the spectrum just to right of white mark.
I can then leave it running for several hours to receive perfect downloads by which time there has been a very slight frequency drift.
I can access German Met Office RTTY data almost 24/7 primarily on 10100khz.
Tuning it is as simple as fine tuning the signal until either I get the call sign;readable reports or four number synoptic strings.
I have also gone back to a book I have on aerials and radio propogation which makes good reading if you are interested in this subject.
www.hamuniverse.com/n4jaantennabook.html
Its a free 74 page book and non tecnical.
For example from what I can gather whilst transmissions are better in daylight that is not necessarily true of reception.It would appear that a transmission at the right frequency sent up into the ionosphere in day light once it starts skipping can continue into a dark zone where ionisation is dissapating.
So what this can mean I think is that if you are out mid Atlatic where local dawn is perhaps three hours later the GMT dawn Northwood will be transmitting at an optimum time for a good skipping signal out into the Atlantic even if its dark at the point of reception.
Anyone not sure about the skipping/skimmimg wave just do a Captain Jack Sparrow in Davy Jones Locker-"skys the sea and seas the sky".So basically you are causing the radio signal to skip along in the ionoshpere the same as if you are skimming stones over the water.

 

[Conachair]

...
I have also gone back to a book I have on aerials and radio propogation which makes good reading if you are interested in this subject.
www.hamuniverse.com/n4jaantennabook.html
...............

For example from what I can gather whilst transmissions are better in daylight that is not necessarily true of reception.It would appear that a transmission at the right frequency sent up into the ionosphere in day light once it starts skipping can continue into a dark zone where ionisation is dissapating.
So what this can mean I think is that if you are out mid Atlatic where local dawn is perhaps three hours later the GMT dawn Northwood will be transmitting at an optimum time for a good skipping signal out into the Atlantic even if its dark at the point of reception.
Anyone not sure about the skipping/skimmimg wave just do a Captain Jack Sparrow in Davy Jones Locker-"skys the sea and seas the sky".So basically you are causing the radio signal to skip along in the ionoshpere the same as if you are skimming stones over the water.

Thanks for the link. Full ham exam in a few weeks so will come in handy.

Re the skip, I´m regretting having a virtual tidy up now, deleted all the faxes recieved coming across Atlantic From memory they were not perfect but plenty good enough to see what was going on. That was with a degen 1103 attached to the car radio masthead FM antenna.

Where are you recieving from at the moment? Your faxes are miles better than I can get. Through an Icom 7000, but surrounded by masts and offfice blocks twice the height of the mast so maybe no wonder.

Dwd on 10.1Mhz comes in perfect mostly during the day but fades around sunset.

Have you tried recieving psk31? A ham data mode, on 3.580, 7.035, 10.141 & 14.070. Fldigi will decode it, then you can watch hams saying hello to each other. For a few minutes ´til boredom kicks in

 

[ffiill]

I am based in Glenmoriston which runs aprox.westwards of Loch Ness.
I am completely surrounded by mountains-the skyline south of me is 30 degrees from the horizontal and to the rear of my house the first three hundred feet is nearly vertical granite.
There is a small window between east and south east where the hills are about 8 miles way but which peak at 4000 foot in the Cairngorms.
So I am assumning the only signal I am getting is reflected.
We are assuming that we are getting a signal from the same transmitter.
I am sure I read somewhere that Northwood uses a series of transmitters from Ascension Island northwards because Northwood itself is near Watford.
My antenna is a horizontally strung 45 foot length of 1.5 mm dia.6 strand twisted insulated wire commonly used for wiring up ceiling spots.Feed line is 70 ohm low loss satellite coax. because I have a load of it!
Also I use a low loss screened digital audio feed-a couple of £s on e bay
Today for a change I also tried the radios onboard whip.The whip showed a far poorer spectrum spike with progressive signal build up either end wheras the antenna has little either side of the spike.
Radio is set local and narrow band ssb.
The wind vector chart begins on the whip and swops over just about where I am in the Highlands ;the prognosis chart I received almost two hours after setting the system on auto running whilst I took my dog for a walk.
Origional pic quality far better than this jpg conversion at 100kbs-1.4 mb per pic.and as I recall about 24x18 inches as transmitted.

 

[Alcyone]

I can't match these yet, but today, after a year or so of messing about, I got this:

Degen Short wave radio. laptop, Offenbach (DDH) weatherfax on 7878.1 Mhz. Software, demo version of JVComm32.

Really messy, and hardly worth anything, but after months of trying to work out what all the jargon means, how the radio works, how the software works, and getting nothing but noise, I'm absolutely over the moon to see an Atlantic weather chart. I fiddled about, and got a much clearer image after this, but didn't manage to save it.

Anyway, this isn't about me, it's just to say thanks to ed for providing the original info, and the other contributors. Cheers, lads.

 

[iainhu]

Was your laptop on mains

Did you have your laptop or radio plugged into the mains when you collected this chart? It looks very like the charts I was collecting...look back to post 56 and others.

In my many and various tests I found mains (left on by mistake) could cause this and setting the 'slant control' also helped, however, your chart seems all neatly lined up, just very 'dirty'.

I guess ensuring the radio is on narrow band tuning might help? Just been going back through my posts to see if I can find the moment I went from this kind of thing to a cleaner, readable chart.

 

[Alcyone]

Did you have your laptop or radio plugged into the mains when you collected this chart? It looks very like the charts I was collecting...look back to post 56 and others.

In my many and various tests I found mains (left on by mistake) could cause this and setting the 'slant control' also helped, however, your chart seems all neatly lined up, just very 'dirty'.

I guess ensuring the radio is on narrow band tuning might help? Just been going back through my posts to see if I can find the moment I went from this kind of thing to a cleaner, readable chart.

I'm learning with every attempt. First time I did have the laptop plugged in. I had a reasonably clear fax sound on the radio, but huge interference when I plugged in the mic lead from the radio. So, as Ed says, don't do it whilst charging.

Then I read that you can use the fine tune dial on the Degen once the frequency is set. That affects whether the fax is translated as mainly black, or mainly white. I was fiddling with this whilst recording - hence the switch from white to black fax and back again.

I haven't yet worked out why I can get faxes from Offenbach (Germany) but not yet from Northwood.

Honestly, I don't care. Once I know I can do it, it's just a metter of time to get the best results, and I'm learning loads.

 

[iainhu]

A black art

Yes it is all a bit of a black art. Look back as I struggled my way through to getting readable charts. However, having done so and being all set to use them trans Atlantic I could get *nothing* once on the boat...contrary to all predictions. Probably RF from the boat, so in the end it became a whole lot easier to use the sat-phone and download gribs, which worked fine, just failed to use my, I thought, new found skills to work!

 

[Conachair]

Anyway, this isn't about me, it's just to say thanks to ed for providing the original info, and the other contributors. Cheers, lads.

This one is fun as well, RTTY from DWD on 10.1MHz. On JVcom if you go into configuration/RTTY and enter these..

mode:Whatever memory you want to save it as.
Type:Baudot
Baudrate:50
shift:50
PTC-11 type:baudot
# of bits : 5
centre frequency:400.

you should get text weather from DWD in Germany. Strong signal usually.

 

[Alcyone]

Apologies, Conachair, I missed your post. I'll try that. Many thanks.

 

[ffiill]

What time were these faxes done at?-all mine are during the daymid morning and late afternoon is best.
Just suprised how poor the quality is-I managed to get good quality within a few days of beginning to experiment.
Several points-fine tune the signal whilst watching the image so as to get it as clean as possible.
You can pick up a lot of spurious sound of the mains-I am in a rural area but can still get a lot of noise sometimes and find that internal batteries are better.
When I was experimenting on the west coast I was getting a lot of interference on some frequencies-perhaps military jamming.
Use a sheilded coax lead between radio and PC.
Always tune down from reccomended frequency.
Set to Upper side band?-if I dont use USB I get a lot of spurious noise.
I am wondering if there are issues with Northwood of being too close.
My signals are definitely ones bounced of ionosphere.
Finally I did manage to pick one up on my long wire aerial if a little unclear from Boston -4000 plus miles away.

 

[iainhu]

Some useful hints, thanks

For my part:

1. I often did my reception in the evening, after dark, which is supposed to be better for signal reception so interesting to hear yours are in daylight
2. I used a PC audio lead...not sure how much shielding that would have had
3. I only ran both radio and laptop on battery except for one accidental use of mains which was very obvious
4. I did all my recordings outside...not a hope inside!
5. I did most of my recording with a retractable (16' I think) wire aerial stretched horizontally which helped 'a little'
6. Yes, you need to tune low the get the upper side band
7. Very impressed at you picking up Boston...makes me feel I should try that again!