ADAGIO’s long range wifi configuration: options for antennas, routers and local wifi

This post is for cruisers who are interested in a very convenient and easy to operate way to translate land-based wifi into your yacht’s local wifi zone. We are very happy with this configuration – this is “generation 3” for us – technology has improved since our first-generation rig installed in 2000. The first section is on antennas, the second section on routing and our local wifi bubble.

 Antenna options:

External antenna: historically we bought our antennas from L-COM. But recently we’ve bought omnidirectional antennas for for both cellular and WiFi from RF Industries (Australian company, often abbreviated as RFI). An excellent New Zealand source for RFI is Paul McKnight +649 537 2683, rfi@xtra.co.nz. Paul may have difficulty advising you what will satisfy your needs – it isn’t just distance, it depends very much on what gear the WiFi base station is using (the router, the antenna directionality, quality and gain).

We are using the RFI COL2410 which is their highest gain omnidirectional. Note there are 3 smaller (cheaper!) versions. I’m not an antenna guy so I won’t speculate whether you would be happy with less gain. Maybe ask Paul McKnight for advice? See pricing of the range of RFI sizes. The 2 dBi is $99, 6dBi is $120, the 10dBi like ours is $170. Telco Antennas is an Aussie company.

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Router options:

For your external WiFi router (to communicate with land-based wifi access point), the options have improved very dramatically in recent years. All of the expense and trouble we endured to install low-loss microwave cable from wet to dry is no longer needed. The reason is outdoor routers that convert the analog signal to digital – so we only need ethernet cable from wet to dry. And we use POE (Power Over Ethernet) to supply power to the little router. We did a good bit of research amongst contacts in the communications biz – the consensus recommendation for our needs was the Ubiquiti Bullet M-2 running AirOS on linux.

Because the WiFi connectivity is often so important to us, we now have 2 Bullets – live and backup. The live/active Bullet was bought from Amazon for about $75. Later I discovered this first Amazon unit was the N. America version which locks out the international channels 12 to 15 where the best wifi is in places like Noumea. You may not care about the extra channels as the cost is slighty higher. If you do care, I ordered the second one from HD Communications for USD $78.50.

To bring the ethernet from the wet to dry we are using the L-COM ruggedized flange mount (when we go to sea we remove the cable and close the gasketed cover).

I also bought an L-COM POE injector that allows us to feed regulated 13.8V into the cable instead of using the AC wall wart that ships with Bullet. If you haven’t dealt with L-COM before, they are my go-to place for anything communications (high quality, low price).

Once you get the ethernet cable inside, one option is to connect your computer’s ethernet port directly. Then have the PC create a WiFi zone inside the boat for your other devices. Another option is to spend another $30 – $40 for the convenience of our setup. For the in-boat WiFi we repurposed our old external WiFi router, an Engenius ECB3500,  configured as Operation Mode = Access Point, fixed IP 192.168.222.21 (Note the other fixed IP addresses must be carefully chosen – ours are Bullet IP 192.168.222.20 and Bullet-router DHCP range 192.168.222.50 – 99).

The ECB 3500 has no auto collision avoidance AFAIK, only fixed IP or DHCP. So I used the Bullet’s site survey to assess channel collisions, then assigned the 3500 to CH4. I adjusted the ECB 3500 transmit power to minimum 9dbm and removed one of its 2 antennas. That got the 3500 down to about 7 dbm below our wifi ISP as seen by the Bullet site survey. Speed tests using an iPad to sample various areas around the boat are OK at around 2Mbs.

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