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Has anyone gotten wefax to work with openplotter using rtl-sdr? Is there a reason the weather fax plugin for opencpn is not part of openplotter? Is the AIS radio in the moitessier hat tunable?


Thanks

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(2020-03-20, 04:23 PM)Josacraw Wrote: [ -> ]Has anyone gotten wefax to work with openplotter using  rtl-sdr? Is there a reason the weather fax plugin for opencpn is not part of openplotter? Is the AIS radio in the moitessier hat tunable?


Thanks

Sent from my SM-G920P using Tapatalk

I think someone got wefax, we will add an app for SDR-VHF and another one for SDR-HF (weatherfax)

istalling opencpn plugins is easy, just one click so we do not include any plugin by default.

What tunable means? you cant not get voice radio. What do you want to change? install the moitessier app and you will see the options. You can even simulate AIS reception.
(2020-03-20, 07:59 PM)Sailoog Wrote: [ -> ]What tunable means? you cant not get voice radio. What do you want to change? install the moitessier app and you will see the options. You can even simulate AIS reception.

I meant is it possible to change AIS receiver on the hat to other frequencies. It would require an antenna splitter to do both with the hat sdr so perhaps it would be more sensible to use a separate usb rtl-sdr for wefax reception.

My only experience with wefax involves receiving with gqrx and piping the audio to fldigi with pulseaudio. Can the opencpn plugin simplify this and take the place of fldigi?

Thanks

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I don't think the radio on the moitessier hat is tunable but I could be wrong.

With rtlsdr and dvb-t dongle you can tune but HF frequencies are difficult.

I used a board called an upconverter which makes reception possible but the result (using weather fax plugin) was slightly worse quality than $40 ssb receiver tecsun 600. In both cases I did not use a sufficient antenna but weather maps were readable.

So it is possible. Let us know your results and also very interested in direct mode which allows HF reception without upconverter (But even worse quality??)
moitessier HAT is not an SDR receiver, it is a dedicated AIS receiver. You can play with some options but you will get only AIS data.
Any tips on getting the wefax signal using gqrx? I'm using the rtl-sdr v3 with a 30 foot length of cat5 cable strung up in a tree. The wire is plugged into the center pin of SMA jack. The Boston wefax is the closest to me at about 900 miles. Gqrx is set USB mode with everything else default. I see a signal spike at 12748.1khz but only hear static. I've also tried the new Orleans station which is about equidistant. I have looked into various shortwave antenna styles but effectively they are what I have done. Maybe I'm just to far away? I have tried night time as well knowing you should get better reception then. The sdr is definitely working as can pick up local FM stations no problem.

I can also pick up a series steady tones from low to high at the frequencies just below at 12746 and lower

Thanks

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After a long hiatus I am revisiting this concept. Turns out wefax reception is very poor when you live in a wooded area so I moved to an area with clear sky. I've been able to record and decode transmissions on my laptop using gqrx and fldigi.

I have been far less successful on openplotter using the same antenna and sdr. The reception is just so much worse! It helped to move the sdr from a usb hub to a directly into the pi. I've also tried using a 3 or so foot dongle cable to get a little distance. I can receive images but they are very poor.

I have yet to get the opencpn plugin to receive anything(by that I mean it returns a lightly staticed white image). I added the direct sample flag to the rtl_fm command under the scheduler tab and set the upconverter offset to 0 since I'm using a v3 rtl-sdr. Is there something else I'm missing?

Thanks!

Perhaps it would help to turn off the ais sdr on the moitessier hat while receiving?
(2021-04-23, 01:53 AM)Josacraw Wrote: [ -> ]After a long hiatus I am revisiting this concept. Turns out wefax reception is very poor when you live in a wooded area so I moved to an area with clear sky. I've been able to record and decode transmissions on my laptop using gqrx and fldigi.

I have been far less successful on openplotter using the same antenna and sdr. The reception is just so much worse! It helped to move the sdr from a usb hub to a directly into the pi. I've also tried using a 3 or so foot dongle cable to get a little distance. I can receive images but they are very poor.

I have yet to get the opencpn plugin to receive anything(by that I mean it returns a lightly staticed white image). I added the direct sample flag to the rtl_fm command under the scheduler tab and set the upconverter offset to 0 since I'm using a v3 rtl-sdr. Is there something else I'm missing?

Thanks!

Perhaps it would help to turn off the ais sdr on the moitessier hat while receiving?

This is good info. Thanks for posting. I’ve not gotten there yet, but a version 3 is on my list, as I have a Ham it Up and it’s about worthless. 

Over on the OpenCPN forum I had the discussion with Sean, the programmer of the Weatherfax plugin and he did program it to work with an SDR but didn’t have one to test, so it’s possible that is might work. See here: https://www.cruisersforum.com/forums/f13...49387.html post #7.

BTW, I know nothing about this, but am trying to figure it out. My plan, if it would work, is to use a balun to attach my built in ground plain and my isolated back stay antenna. Then just let the plugin tune the dongle and receive faxes at it’s leisure right into OpenCPN. Obviously that’s overly simplistic (it’s a boat after all), but it is my ideal scenario.
Could be well worth looking at SOX, I've had that running a funcubedongle before,just record the audio live then do what you want afterwards. The opencpn wfax plugin will accept an audio file as input, not receiving and decoding at the same time uses a lot less resources.
(2021-04-23, 08:01 PM)PaddyB Wrote: [ -> ]Could be well worth looking at SOX, I've had that running a funcubedongle before,just record the audio live then do what you want afterwards. The opencpn wfax plugin will accept an audio file as input, not receiving and decoding at the same time uses a lot less resources.

Good point. However, it also requires user interaction, which is where I’ll usually mess it up. I’ve long be a proponent of automating tasks to remove the errors of the human element.
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