Once offshore the internet is inaccessible by a laptop without assistance. To connect a laptop to HF Radio you will need a packet-data modem such as the Pactor to connect to your radio, then some additional hardware to connect your Pactor to the laptop. With this system you can connect to the internet for basic things like sending and receiving email and receiving weather files. The resulting transfer of data is quite slow and does not permit you to peruse the web or send images, but it gives you the basics for safety and communication with those on shore.
A HF Radio (we have the ICOM 735) can transmit packets of data from the internet or from specific senders when attached to a Pactor Modem. The modem receives these packets of data and downloads them to a connected laptop. The software I use to assist with this job is Airmail. The hardware connection depends on which version of the Pactor modem you are using. Older Pactors use RS-232 (serial connection) but the newer ones use USB. If you have one of the older RS-232 devices, read on!
Side note on Pactor Modems – if you have an older one see if you can get the software updated to Pactor 3 and you will get two to three times faster data speeds. Many can be updated just by paying the $169 fee, others, like ours, have to be sent to Farallon Electronics to be upgraded and so will cost a little more.
How to connect a serial device (RS-232) to your laptop
Since modern laptops no longer use serial ports, and many older boat electronics are serial port devices, you may need a RS-232 to USB hub. To the laptop, it’s just a USB hub, accepting up to 8 devices. But it allows you to plug in those RS-232 devices.
I need the serial hub for my Pactor Modem, the Weather Fax and the AIS. I plug these three devices into the hub, at right, and my computer can then communicate with them. All of these devices are also sold in USB versions now, so unless you have older hardware you may not need to worry about RS-232. The only RS-232 hub I have found that reliably works with Windows 8 or 10 is the SerialGear hub pictured at right. I would get two so you have a backup. If you want to plug a Weather Fax and old style GPS into this hub as well then you will fill it up, but I can’t think of a reason anyone would need an eight-port unit on a boat.
If your Pactor Modem and AIS already have USB cables, excellent! You will need a normal USB hub to collect all those inputs. Get a high quality one with USB 2.0 and then get a backup or two. USB 3 is faster but the devices you are connecting to only need USB 2.
Note that you will also need to connect your Pactor Modem to your Radio, but that is beyond the scope of this article. The connection varies widely depending on the radio model you have and to some extent on which Pactor Modem you have.