Ocean Navigator Communications Newsletter #24

Everything You Wanted to Know About Communications - And Weren't Afraid to Ask

I'll dedicate this issue of the newsletter to answering the many questions I received about the variety of equipment we have aboard, Aurora, the 47' ketch which is serving as a testing platform during the current trans-Atlantic passage from the Canary Islands to Antigua. Here's a list to recap what we have on board:
- an Inmarsat Mini-M (Thrane & Thrane 3060)
- an Inmarsat C (Thrane & Thrane 3022)
- an Iridium portable telephone (Motorola 9505)
- a Globalstar telephone (Qualcomm GSP-1600)
- a Boaters Mini Web system
- single sideband radio (SEA 225)
- single sideband receiver (Icom PCR 1000)
- email software & service from UUPlus
- email software & service from MarineNet

Now, on to your questions.

I received email from a few people asking about the Boater's Mini Web system. While it was a little difficult to get things going initially, I got a great deal of support from the company in Virginia, and eventually managed to trace the problem to a faulty antenna. Likely damaged in transit from Maine to Grand Canary. They sent over diagrams of how the wiring should look, and with a little electrical tape and patience, I managed to rig up a temporary solution using the boat's VHF antenna. This would have been easier if I had brought along the optional antenna-sharing switch offered with the system. The disadvantage with using the boat's VHF antenna for the Boater's Mini Web system is that we can only use one system or the other at any given time. So, to sail without a working VHF mid-ocean isn't a tragedy, it would be far more convenient to have both systems operational simultaneously. Since it's just a quick cable swap to hook the VHF back up, we do this whenever there's a contact nearby. Once the antenna problem had been fixed, the system has been working more or less reliably.

It's a store-and-forward system, meaning that I click the "send email" button and then the system will at the most appropriate time in the future actually forward my email message to the satellite for further delivery. This is important as satellite coverage is not 100%. It is location dependent, and right now (about 850 miles east of Antigua) I'm getting about 50% coverage. So there's a 50/50 chance that a satellite is in view at any given time. This is where the store-and-forward piece comes in. If there's not a satellite available now, the system will wait to find one and then forward on the message.

There are a few extra bells and whistles, most of which work reliably, though some are still going through some growing pains. The email to fax and email to voice systems seem reliable. The weather on demand service hasn't yet come through for me -- I'm supposed to be able to request a high seas text forecast, but so far no luck. Tech support is working on this - and given their track record I'll bet it will be fixed by the time you read this. The automatic position reporting works well most of the time - I can set the interval to hourly, every 3 hours and so forth. If a GPS input is available, it will use that for position information. Otherwise, it can estimate our position, though it sometimes takes a few hours for this calculation to kick in. The hourly reporting I'd set up was working like a charm, with one exception two evenings ago, when my colleague Tim Hasson called frantically on my Iridium to tell me that he was getting a position report every 60 seconds!

I also got several questions about the PCR-1000 which I'd written about in a previous email. It's been performing as expected. I brought it along with the intention to have it contiuously receiving weather faxes without needing to tie up the boat's main SSB. Among it's advantages - it's small and portable and easily carried in personal luggage to the boat, it's very easy to interface to a computer for weather fax reception. Among it's disadvantages - my computer needs to be on and connected in order to keep the receiver going. If I take the laptop to the cockpit for some writing, I need to be aware that the receiver will be out of commission until I hook it back up. It's standard antenna, a small telescoping whip about the size of a car radio antenna, is dismally inefficient mid-ocean. A simple solution would be to hook the antenna up to a long wire hoisted up the mast. Or better yet, install a permanent antenna for onboard use. It operates on 12 V DC power, but comes supplied with only a 110 V AC brick transformer. It would be a relatively easy operation to cut this off and wire it instead to a cigarette lighter type plug or direct to a breaker. Since we have 110 V power available through a good part of the day, I haven't yet bothered with this. For any future passage, I'd conitnue to bring it along, but after first making the 12 V modification and also bringing along a more suitable antenna. And, yes it works just fine with my Windows XP laptop. Be sure to have a serial port available.

Sadly, we diagnosed a problem with the aged SEA single sideband radio onboard. After several days of making only faint contact with the outside world, we found an interference problem. It turns out that the autopilot causes a significant repetitive noise pattern on the SSB. Almost as if someone is trying to transmit Morse code in bursts of static. Steering by hand is strictly against the rules on this leisure cruise, but at Tim's encouragement we've been granted a waiver in the name of science. There's still a good deal of white noise even without the autopilot, and the ground plane for the antenna looks like it's in need of an overhaul as it consists only of a few feet of copper ribbon wire-clamped to a fitting on the water tank. It may extend beyond that to other tanks, but there's no way to tell without ripping apart the bilge. So for now we're living with a limited SSB range..

About the Globalstar phone -- Worked like a charm in the Canaries. Coverage was good and consistent, and as expected the sound quality far surpassed both Iridium and Mini-M. Of the three, the Globalstar is the only one that approximates the sound quality of a cellular or even land-line connection, while the other two sound more like you'd expect a satellite telephone to sound. However, also as expected, within a couple of days of leaving the Canaries - the phone's coverage was too spotty to complete a call. This continued to be the case across the ocean. Now at 18 24 N and 44 27 W (about 900 miles east of Antigua) - coverage still isn't consistent enough for a call. I expect things will kick back into gear once we approach Antigua.

The last batch of questions dealt with receiving weather faxes via SSB or via Internet. I'll cover this in more detail in a future newsletter, but for now will build suspense by admitting that Internet reception is far clearer and easier though it comes at the cost of the airtime for whichever system you use, while the SSB weather fax charts are free for the grabbing.

UUPlus has been an oustanding success, and MarineNet promises to offer similar results. I'll defer this comparison as well for a future newsletter.

Oh and Paul H, sorry I'll miss you in Antigua -- we'll be leaving on Dec 17th a few weeks before your arrival.

In the meantime,
Keep in touch.

Regards
Dan Piltch
dpiltch@MarineComputer.com