Just how far can we take the Laptop/Tablet?

[jwcolby54]

Originally Posted by Lake-Effect

I have yet to see a 25W VHF transmitter USB dongle.

No but VHF amps are common place. So get the low power widget and amp it up to whatever you want. A 25 watt amp would be tiny. An antenna tuner would be needed. And a lot of VHF knowledge. But still...

[skkeith]

I say leave the laptop on land. I am working on a 'banana pro' ( ~$50 ) based opensource boat box. All sealed, except 12V and VHF antenna in. 7" touch screen on the front. GPS and VHF receiver dongles + RF24 packet modem sealed inside. RF24 NMEA routing broadcast to any node in the boat. Have not yet measured the draw, but somewhere around 220 mA for the BPro alone. Since they are only $50 each and self contained in a 2.4Ghz mesh, you can mount them near radar or ther NMEA sources broadcasting to every node in the boat automagically if you don't want to run cable. OpenCPN is the front end of couse, everything else is hidden from the user.

[skkeith]

Also in regard to using an amp on a weak VHF signal to improve AIS reception, it will not work. Bad AIS reception is caused by noise and not a weak signal, an amp will just amplify the noise and the signal not changing your situation. You need a proper antenna:

High Gain Collinear AIS (162MHz) Receiving Aerial


and you might try to 'filter' the signal not amplify it if you have noise.