Receiving weatherfax via ssb & Seatty

Sy-Revolution

Sy-Revolution

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Hi Folks,
Trying to receive weatherfax on my laptop using an Eton E5 ssb receiver and SeaTTY without much success.

What's the best frequency for Northwood (I'm east of England) and what mode should I use in SeaTTY?

Total newbie so any other tips gratefully received.

Cheers,

Crispin
 
Download the current weatherfax schedule from HERE, check that you have tuned your SSB to 1.9khz (see page 6 paragraph 3) below the published frequency and report back here if it still isn't working.
 
I notice you are in Ips. I live a few minutes walk from the wet dock. If you draw a blank then PM me and I will come round and show you. Its one of those things that takes pages and page to describe but a few minutes to demonstrate!
 
Can you hear Shannon Volmet (voice met reports) on 5505khz?

Is more or less continuous and should be pretty solid at this time of day. If you can hear that at good strength it means ant, ground and rx are ok at about 4 - 5Mhz.

If you can't hear it, don't even bother with Northwood until you have shaken down the reasons why.
 
Hi Shmoo,
I think that's got to be my problem. I can just about hear Shannon Volme, but only just and with alot of hiss and a high pitched whine.
I'm using the wire ariel that came with the radio. I'm at home in Cambridge at the moment, I'll try on the boat next week,

In the meantime is there a station closer to me or that I might stand a better chance of getting a better reception?
 
closer dosn't always mean better on HF. In fact one of the probs with Northwood is that we are too close in uk. Have to rely on ground wave at this close range.

The whine and hiss may be the pooter: does it vary as you re-orient the pooter or type and change the screen display? Bigger separation may help. I use a tuner under the lazerette so the lead from the rx is screened in the area local to the pooter noise. This option is only really open if you have a transceiver though.

Does the noise go up with the pooter plugged into the rx? I can get Northwood fax to resolve quite well with the pooter listening to the rx speaker with its built in microphone, though I am not recommending this! The last resort here is to use an audio range transformer to isolate the rx from the pooter (or something like a RigBlaster)

May all be better on the boat - get an ant. up in the clear on a spare halyard and the extra signal you bring in may be enough to drown the noise.
 
Shmoo,
Yes I do get some noise down the line from the laptop, I tried making a line isolator lead but I don't think I made it correctly because it didn't filter anything out.
I have had much better results with my PC, shame because I was hoping to use the laptop that I already own, and use little , on the boat but may not be able to if I can't resolve the interferance issue. I've tried using a USB sound card instead of the laptops one but didn't improve much.

Perhaps I'll have to invest in a pre made line isolator cable.......
 
In my experience much of the hash that comes out of a laptop (apart from that which comes up the wire) comes from the flat screen. It has a lot of quite fast switching going on over a big area - like an aerial. Orienting the laplop screen for minimum noise may work a bit.

What you want is to increase the signal to noise ratio and if you can't decrease the noise then work on increasing the signal with a long aerial up in the clear. Perhaps try an active aerial some way from the nav station (and the noise) and lead it back with screened cable. Don't use screened cable without either an active aerial or a tuner on the end - it won't screen and you will loose signal.

Ferrites round the cable may work. Prise them off old keyboard leads at the local dump. Put them as near each end as possible.
 
take a look at the signal/noise thing on the software. I always had to turn it right up to screeching point then all the pretty lines started coming in. turn down the volume on the pc turn up the volume on the set then tune across freq

Ian
 
Agree with Ian - this is why I said this stuff was easier to demo than describe in writing!

Long aerial is just long length of wire - that's all. Multi stranded and tinned is best. Use a couple of plastic decorative garden chain links as insulators at one end and haul it aloft. Active aerials are hard to source for HF: a kit is the nearest I have come across and this is not recommended unless you have some experience home-brewing radio equipment but search for "active" on this http://www.wsplc.com/acatalog/Kits_Ten_Tec.html page for what I mean.

Don't give up - you will get there and the Northwood maps are a great resource. Getting maps for the whole north Atlantic every 24 hours for next 4 days has given us great confidence to do crossings we would not have considered with only the shipping forecast to go on.
 
aerial - long length of wire wrapped around NOT CONNECTED TO the backstay - induction will do the rest - then you need a good ground plane to the anode or summat.

you will get there but it takes a lot of fiddling - don't give up - you'll learn the beepsing sequences that bring on a picture.
it's a magic moment when the weather maps come in - trouble is there are too many of them - including all the ice predictions for the noth atlantic etc..
 
or buy a sat phone - connect email up and request gribs for 1 2 and up to 5 days - they are super accurate to the nearest couple of knots and it only the wind we really care about anyway?

If you compare a grib to a normal synoptic the picture comes clear..
 
Might be worth letting the operating system turn off the screen as in screensaver. Could be a rough and ready check.
Inverters are pretty noisy beasts as well so could be worth using it on just the batteries and if this is successful perhaps maintaining battery charge using a linear regulator.
I have had similar problems with a desktop PC some years back and used a filter between the PC and the receiver to help reduce the interference fed back down the line.

Neil
 
You can't compare those awful sticky grib things to a real met chart. There is something satisfying about the idea of a WREN deep under Northwood flashing up a 50 year old Muirfax machine, clearly descended from a lathe, to send out real weather maps. If anyone is thinking of posting messages along the lines of "they do it all on PCs now" - please don't.

Besides, if the admiral discovered you could talk on a sat phone...
 
Re: Receiving weatherfax via ssb & Seatty

I have a Nasa HF3 (?) whith active antenna. Its connected to my laptop, formmerly with Meteo Scan and now on new laptop running Vista with JVComm 32. I have never really got my head around it as it never works in harbour but worked perfectly in the middle of Biscay when I tried it but that wasn't the idea place to experiment. I concluded that there is too much interference in harbour. Does this sound likely? My mooring is on the Dart, lots of hills around. I find the instructions quite confusing as it always seems to assume more knowledge of the subject than I have got.

Thanks for any advice

Colin
 
Re: Receiving weatherfax via ssb & Seatty

Sounds very reasonable. Too much noise in harbour and too close to Northwood to get skywave. Groundwave works on lower frequencies up to a hunderd miles or so but is not ideal. We use an insulated backstay through a tuner and that pulls in a passable signal on East Coast. It is better at sea though and better once we get to West Country. The other problem with being close is getting both skywave and ground wave and this causes a second ghost image a millimeter or two displaced.

That all said, you should get something
 
Re: Receiving weatherfax via ssb & Seatty

I too am using a Nasa HF3 with Meteo and Seatty.I use a Nasa active antenna.
It works perfectly on a PC,but the Fax picture is totally distorted on my DELL Inspiron1501.
Any help out there ????????? /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif
 
Re: Receiving weatherfax via ssb & Seatty

[ QUOTE ]
[Seatty].....works perfectly on a PC,but the Fax picture is totally distorted on my DELL Inspiron1501.

[/ QUOTE ]


Depends what you mean by 'distorted'.

Have you set the slant correction? That is very different on different monitors. For SeaTTY, you record a fax, or just a fragment of a fax, stop recording, then press the 'slant correction' button (it is greyed out when receiving a fax, just left of the M- button). Drag a line down what you think should be a vertical, and allow it to adjust the display. If it is really way out you may have to do this a few times to get it right.


Or do you mean 'noisy'; could be RF interference from different PCs.

For fun,I just got this from DDH Germany (4,000 miles from me) and with a wrong slant correction. It looks like this:

distorted-1.png


Then corrected the same image looks like this:


correctd.png


(to save bandwidth these are small slices that don't exactly match, but you can see the effect)
 
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