20$ AIS

[joel383]

https://translate.google.com/transla...r-for-opencpn/

Obviously not ready to make into a primary system, but my imagination is running wild with sdr options!
1.AIS
2. WEFAX
3. Actual NOAA images and data from satellites
4.???

And portable too. Looking to integrate into my samsung galaxy tab 3 which already has onboard GPS. Once I root and get OPENCPN running, i will have a full 3rd redundancy for e-navigation. Loss of all power could be worked around by keeping an isolated back-up battery, simmilar to those found in UPS backups(small agm battery). Which coupled to even a small solar panel could run a really long time, if not for the remaining duration of the trip.

[biker6977]

That looks very interesting. I'm not much of a computer person but may try this here in Mobile Bay where we have lots of tanker traffic and see if I can get it to work. Thanks for the info!

[HappySeagull]

Originally Posted by biker6977

That looks very interesting. I'm not much of a computer person but may try this here in Mobile Bay where we have lots of tanker traffic and see if I can get it to work. Thanks for the info!

IMO, the "vertical polarized antenna adjusted to 162MHz" mentioned will be an important component....but you can try to tune an antenna from a plain jane FM radio or a coathanger...my results were not encouraging. The quality of the RTL Dongle I have is not great.
An old scanner or VHF radio works better for me.

[mattkab]

I do this technique on Raspberry Pi and Cubietruck platforms and it works great. No idea how (or even if) it would work on your tablet.

There is quite a bit of setup and tinkering to get it right, but once you do it is very effectve. Even using the cheap supplied antennae I get signals from over 20 miles away.

I have a splitter for my VHF radio now, but haven't hooked it up to the device as the connections don't match and I need an adapter. Yet another thing I want to work on this winter.

[hellosailor]

SDR can be very interesting. And the antenna more important than you might think. Simply using a horizontally polarized antenna (i.e. something laying down flat instead of vertical) can cause a 20db signal loss compared to a the same plain vertical whip. That's about a 64x difference in signal strength. Splurging on an inexpensive "emergency" antenna and connecting that up to the SDR might be a good idea, if you've no taste for making one.

[joel383]

Im looking into a qfh antenna to recieve the circular polarity 137mhz noaa satellites. Making one rugged enough to take cruising on the boat is going to be a trick though.

Sent from my SM-T210R using Cruisers Sailing Forum mobile app

[seandepagnier]

I have seen someone with a double helix antenna for satellite imagery

[joel383]

Originally Posted by boat_alexandra

I have seen someone with a double helix antenna for satellite imagery

That was probably a quadrifilar helical antenna, looks very similar to a double helix