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Old 12-15-2006, 08:27 AM   #1
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Default Icom M802/AT140 &Winlink

Santa has informed me that I will be getting a couple items from the top of my wish list at Christmas ie, Icom M802 & AT140.

http://www.icomradiosdirect.com/m802.html

Once I complete my general exam and 5wpm, I'll be all set. So, my question is this: does anyone have advice or insight as to the laundry list of things that I will need to integrate the system into my glass hull with my computer in order to send and receive email via winlink over HF? I have been told that this will be a major job to achieve the proper counterpoise for the back stay antenna. Also, I here that email access isn't plug and play like they advertise.
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Old 12-15-2006, 09:50 PM   #2
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Trim:

First, congratulations on asking Santa for some really neat stuff!

Second, the ONLY people I know who say HF radio (let alone pactor HF) is 'plug & play' are a few vendors. The rest of us, including all the principals of Sailmail and Winlink and many vendors, are quick to say the reverse.

Third, there are two learning curves: the first one is the installation itself, and the second is to build skills at using all that technology effectively, efficiently, and with respect for the bands and the rest of us who are trying to do the same. This is not like installing an autopilot or watermaker. OTOH many of us have climbed the ladder before you and, if putting in the effort up front, feel very rewarded with the results.

Fourth - and to get to your Q - you have some outstanding resources available to you; use them. Read the Pactor Primer on the Sailmail website and the help files in Airmal about installation, RF loops, etc. That information, all written by Jim Corenman who is a technowizard central to both HF email systems, an excellent writer and a great guy as well, is all relevant. As for ongoing support, the best source I know of - better even than the ham-related forums - is the Communications area of the SSCA Discussion Board. The accummulated content there is excellent and the product of some real field-tested experts. You'll find the current DB and topic area at http://64.70.221.24/DiscBoard/viewforum.ph...65ed1ebbd0cd35a Use the Search engine. Read the instructions for accessing the old Board (which has content that could not be imported to the new Board) and use that Search engine, as well. Everything you will want to know about has most likely already been documented there. Some of it is in geek-speak; some of it is contradictory; much of it is manageable. Welcome to the world of HF radio.

Lastly, dip into the ham radio community beyond just mastering your 5 wpm. Visit the local club on meeting night, introduce yourself, explain you are about to jump off the cliff and you would really appreciate a few 'Elmers' to be available when you need someone to talk to. Few communities are as mutually supportive as hams; of course you want to ask for their help.

Good luck to you. And don't fret: with the right expectations, you won't be overwhelmed by the task and you'll end up with a good station and receive all its benefits.

Jack N3FYP

WHOOSH, wintering in Gzira, Malta
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Old 12-16-2006, 12:53 AM   #3
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Jack,

Thanks for the information...I will definitely visit the sight. One specific question that I had was size of the counterpoise. I have two stainless steel 200 gallon water tanks located midship port & starboard that I'm hoping will provide enough grounding area if they are bonded together with the engine using battery cable or copper strap. I estimate the surface area of the tanks at about 100sqft. Will this be enough when combined with the surface of the engine?

Lori & I just passed our Technician exam last weekend and we are pretty excited about getting our general now. Lori was worried that she wouldn't pass the exam...she ended-up getting the same score I did. So now she is suddenly motivated to continue with the process. I'm really hoping she takes ownership of the radio and communications onboard. Something that I was really amazed by was how many people there were at the exam session. I counted nearly 40! I had no idea HAM was so popular.

We are planning on setting-up the system in our house for a while and using it at home to learn. Any suggestions on a low cost antenna system for a temporary home base?

Kind Regards

Ken

Also, I was talking to a HAM that works with me and I told him that I'm really concerned about this venture with the radio because it is like placing one expensive hobby inside a more expensive hobby. He agreed with my concern for my bank account.
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Old 12-18-2006, 07:43 PM   #4
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Ken:

You'll see even MORE interest in the ham exams in the near future; the FCC just announced that it finally is eliminating the code requirement.

The 'home first, boat later' approach is one good option (that's what I did) but I don't think I would prefer it if I had regular access to the boat. It sounds like your cruising plans are somewhat imminent, in which case perhaps it's better to apply all the installation and learning curve time to the boat station.

There are lots of views on counterpoise systems (as you'll soon learn). There is a general consensus that it is NOT a good idea to tie your RF ground into your DC ground (these are two very different things) as you provide additional paths for RF loops within the boat. That would preclude using your s/s tanks as they are and should be grounded to the boat's DC ground. Another 'biggie' is to avoid powering your radio from your DC panel; avoid this *completely*. It should be powered directly from your house bank (via + and - fuses) as the battery bank suppresses RF loops very effectively.

"How much" counterpoise is very vessel-dependent. A good general rule of thumb is to start with those rf ground sources that are easiest (not necessarily biggest) and keep adding sources until you have an effective station. There are many good sources of counterpoise, including the boat's ballast keel, aluminum toerails on deck, lifelines and pulpits, the stainless rub rail cover (tie the rub rail sections together with 'jumpers') and by the use of lengths of copper foil (radials). What's most accessible from your tuner would be my first criterion. However, don't overlook the rec to add a T-4 large ferrite isolator just ahead of your tuner; it is a big help to station performance and is dirt cheap relative to its value ($30 or so from Radio Works). Again, see the Pactor Primer.

There is a strong view held by some that ALL counterpoise sources have to be above the waterline. The theory holds that water kills rf propagation...so e.g. a ballast keel won't work as a counterpoise. I've found this to be totally false (a ballast keel was the ONLY counterpoise I used initially and I was often the 'go to' guy in the anchorage for getting email out and wx f'casts in). But, like many other aspects of ham radio, views can be rigidly held. Try what works for you and see how it functions on your boat, and form your own opinions.

I don't agree with the notion that you are putting one expensive hobby inside another, altho' it's a cute way to describe it! You are certainly making a sizeable initial investment ($4K by the time the last ferrite chokes are added?) but, unlike your boat, from that moment onward, you'll find the radio station keeps earning its keep and asks nothing further from the budget. We've been using Winlink as our primary email and wx f'cast source for 7 years now, and it's cost us nothing once the installation was complete. By 'boat standards' that's amazingly cheap! <g>

Feel free to contact me directly if you'd like to discuss any installation-specific issues; I'll be in the USA for another month before returning to Malta. I'm not one of those ham techno-whizes but I have learned a few things about installing and using radios on boats.

Good luck to you, and congratulations to your wife!

Jack

jack_patricia at yahoo.com
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Old 12-19-2006, 12:39 PM   #5
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Jack,

Correct me if I'm wrong here, but my understanding of the counterpoise isn't that it needs to propagate rf, but rather that it provide a sufficiently large ground for the signal to electrically "push-off" through the antenna. I do not see the logic in having the counterpoise above waterline...in fact I would think that you would want the capacitive couple with the water.

I just found this at ICOM:

http://icomcanada.com/techbulletin/t..._grounding.pdf

They specifically say that you want the counterpoise below the waterline. Strangly enough, 100sqft is recommended...so is the keel. This would tend to be supported by your results using your keel.
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Old 12-19-2006, 07:06 PM   #6
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Ken, you will discover that Icom's installation guide - especially WRT the counterpoise - is greeted with great disdain by most hams. Odd, isn't it? You would think they would offer rf ground instructions which would be considered as good as their hardware...but they don't.

The basic theory of the groundplane is that the 'pushing off' that needs to occur is from the surface plane of the sea. Thus, the rf has to get outside the boat to that surface plane. The objection to laying radials, using the keel, and otherwise using counterpoise sources below the waterline is that water attenuates rf dramatically, keeping the rf from reaching the surface plane in any measure. This hasn't been my experience but you can spend some very boring time with others who will explain the theory to you.

As I said above, what determines an adequate counterpoise is very vessel dependent. 100 sq ft might mean something to Icom but it doesn't mean much to you. Again, start with those sources that are easiest to run foil to (from your tuner), and try to get a decent collection of rf counterpoise sources hooked together (and independent from your 12V negative ground). Then start using your rig, and see what the performance of your rig is - sending and receiving - on multiple bands, mulitiple modes.

Jack
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Old 12-31-2006, 08:40 PM   #7
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Hi Ken and Jack,

Thought I would add my 2c worth. I am a delivery skipper and deliver catamarans from Cape Town to destinations all over the world. I am also a HAM. The cats I deliver are not equipped with HF and thus on each delivery I do a temporary installation of my Icom 706, AH-4 tuner, SCS modem and laptop. This gives me all the communications I need for delivery trips. I stand my 706 on the chart table and run two cables back to the tuner (tuner control cable and ant. cable), which I strap in the engine room or aft locker of the boat, depending on the size boat. From the top of the tuner I lead a 13.5 metre wire, which I have inserted inside a 10mm rope, about 3 quarter up the mast with the section of the rope that has no antenna wire in it, continuing up to the top of the mast, thru a small block and down again to a cleat at the bottom of the mast – this so I can adjust the tension of the antenna rope. I use one insulator to ensure that the antenna wire is kept away from any stanchions etc. The 13.5 metre length of wire is calculated to ensure that the tuner will tune up an all marine and HAM frequencies I use.

My earth or counterpoise is simply another 13.5 metre length of wire which is connected to the earth connector of the AH-4 tuner. This is led out of the fibreglass hatch and trailed behind the boat in the water. The only thing to remember is to roll up the wire before entering an anchorage or marina. I have excellent comm’s at all times and send and receive email via Winlink three or more times per day. One of the tricks on good comm’s is to choose the right frequency and land station for the time of the day. Do install Icepac, the propagation software available via the Airmail site.

The biggest problem with HF is to be able to suppress the QRM that is generated by the autopilot and navigation electronics as well as the refrigeration on board most modern boats. I find that when I want to use the HF I have to turn off the refrigeration and put a big card on the DC board to remind myself to turn it on after any QSO. The nav electronics also create a lot of interference and on days of weak propagation, I have the helmsman hand steer for a short time whilst doing a Winlink connection. It would be nice for the manufacturers of the different nav electronics to build suppression ferrites into their systems but it then pushes up the retail price!

Anyway, Jacks advice is spot-on. One thing I have learnt over the years is that the most vulnerable piece of equipment in the whole set-up is the laptop computer. Just make sure that it is packed away in a well padded bag after use – do not leave it on the saloon table. It is a magnet to rouge waves and slamming through heavy seas tends to knock all the data off the hard drive (Hi), making it useless until you can have it repaired or replaced.

John – ZS1JNT – doing Cape Town to Mallorca deliver end Feb 2007.
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Old 01-01-2007, 01:41 AM   #8
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John, excellent post and from real-world experience, too.

I notice that you, like me, have not found the coutnerpoise being at/below the waterline to be a horrible thing. It's amazing how adamant some hams are about that not working.

Good luck on the run up to and into the Med. What a strange experience it must be to arrive in Mallorca without all the charter boats - somewhat like a Neutron Bomb went off, I imagine. <g>

Jack
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