Installing an ICOM IC-M802

[mestrezat]

I purchased all the components(at least I think so) to install my ICOM M802. Radio, tuner, GAM antenna, Pactor III modem. I had planned on having my local boat yard install it but then the transmission blew and there went the money for that. Plus, they wanted to grind off an inch of the thickness of my hull to mount the Dyna Plate to my boat(hull was too thick they said).

Now I will be installing it myself. Please keep in mind, I haven't really got a clue on how to do it. Still a bit mystified as to the copper I have to install and how the heck to do that plus grounding it.

Does anyone have any suggestions on the easiest way to install it(and still have it work)? Is there already a thread on this site? Any handy books?

I don't want to screw this up.

[witzgall]

The only think I have to offer is to question your use of a Dynaplate. I have read that they are not very effective as they foul up quickly. Think of the counterpoise as the other leg of a dipole antenna. Here is what I am thinking of doing for my newly aquired ham radio:
You can accomplish this with cut lengths of wire that are tuned to the bands you need to work in. Then fan them out on one end, connect the others to a common point and attach that to 1-2 inch copper strip that runs back to the tuner. Then a short braided run form the strip to the actual tuner. Install in either your headliner or bilge. I am new to this as well, so verify what I wrote if you think it has merit.

I would suggest not cutting any holes in the boat for the radio until you have everything working

[witzgall]

One other suggestion - go and get your ham license, at least the tech level. I am going to take the test this weekend. The entire question pool is on ARRLWeb: ARRL Home Page, so you know what is going to be asked. It is mostly simple stuff, but the good thing is that there is lots of information that will be useful the SSB operator even if you don't ever operate on the ham bands. I am learning lots of things and the whole marine SSB thing makes alot more sense to be now that I have been studying for this test, and reading for the general license as well.

Chris

[btrayfors]

Disclaimer: I do this for a living.

1. Forget the ground plate...you don't need it. If you've already bought it, sell it or give it away. Do NOT grind off 1" of your hull under any circumstances.

2. Install the tuner as close to the bottom of the backstay as you can (I assume the backstay is where you're going to put the GAM antenna).

3. Run a wide, heavy copper strip from the tuner ground lug to the nearest bronze thru-hull. You can buy the copper at any roofing supply company. Heavy is good because it will last a lot longer in the harsh marine environment.

4. One of the most important things is to assure adequate power to the radio. Use at least AWG6 wire directly from the house batteries, with appropriate 30A fuses.

5. Good connections are critical. If you don't have a proper crimper, buy one or borrow one. Use adhesive heat shrink to protect connections.

6. While RG8X coax is capable of handling the power from an 802 -- and a lot more -- I often use larger and better insulated RG213 or RG214 (double braid) because of its physical properties and better RF insulation.

7. If you're not experienced in putting on PL-259 connectors, seek the assistance of a professional or an experienced ham.

8. Take your time and do it right. Use only top quality materials.

If you're reasonably handy you should be able to do much of it yourself. One formula which has worked well here on the East Coast for sailors who are cash-strapped is to call in a professional for consultation at the beginning -- for planning every part of the installation -- and later in the process to check things and to handle the really tricky ones. This keeps the costs down, and helps insure a good installation.

Bill

[limmer]

Im going to jump in on this because i am at the same stage. as for the tuner how close do you mean to the backstay . does the tuner have to be with the radio itself or can they be apart. as for the gam antenna is that the same as the insulated backstay or is there another way. cheers

[btrayfors]

The tuner belongs as close to the base of the antenna as you can get it. Usually, the tuner is installed under the deck in the lazarette area. It can be any distance from the transceiver...you connect them with a length of coax.

The GAM antenna is a commercial product which has been widely advertised. It clamps onto the backstay.

IMHO, you're better off with a traditional insulated backstay or an "alternative backstay" antenna, based both on technical concerns and on comparisons I've heard on-the-air. It does work, however, and for some it might be a decent solution.

Bill

[nodee]

Bill,
Thanks for your assistance. I, too am in the same situation, although with a catamaran. Would you make any additional suggestions, ie. no backstay, ground plane only in one bilge or both, etc.
Kirk

[btrayfors]

Kirk,

Catamarans can be a challenge.

I installed a marine radio on a large cat here last fall, which worked out extremely well. We used an "alternate" backstay antenna made of insulted s/s lifeline, run from the top of the mast -- on a special tang made to extend aft so that the antenna would clear the roach of the mainsail -- down to a corner of the heavy s/s solar panel arch.

We mounted the tuner just under the deck, connected to the antenna with a length of GTO-15 wire.

For an RF ground, we tried a couple of things, including the BIG s/s solar panel arch, and wound up with just the (also big) aluminum swim platform which spanned the two hulls. This worked out extremely well -- low noise level and very good transmit/receive capability. The boat is now in SW Florida.

Absent the large swim platform, we could have used radials run thru one of the hulls, or a simple ground strap to a nearby bronze thru-hull. Either would have worked, but in this case weren't needed.

Each case is a bit different, though the principles remain the same :-)

Bill

[Stevens 47]

Run a wide, heavy copper strip from the tuner ground lug to the nearest bronze thru-hull.

I am not an expert on this topic (no offense intended to btrayfors) . When I was in the planning stages I asked a surveyor and a electric installer about using a bronze hardware component for a ground connection, they both told me that the single side band have allot of current running through the ground and this was likely to accelerate or cause corrosion to the component. Also it would seem logical that you would have to unbond the particular component from the rest of your metal component's, as they all would become part of the ground of the SSB. I would like to get a definitive answer to this topic some time in the next 3 months I will be installing a ground system myself

[nodee]

Bill,
Thanks for the quick response. We do not have the swim platform but we are in the process of designing an arch for spring installation. Would you suggest any special modifications that we might incorporate into the arch that would enhance antenna installation? We had considered the possibility of just installing a whip antenna on the arch but that didn't seem like the best way to go as opposed to say a ropeantenna.
Also, where on the Chesapeake are you located, if i might ask?
Thanks again.
Kirk

[btrayfors]

Stevens47,

Yes and no (that definitive enough for ya?) :-)

When actually transmitting, there is a lot of voltage and current distributed along the ground line as well as the antenna itself. When you're just listening, these are not present, except in miniscule amounts.

It is true, however, that it's a very good idea to separate your RF ground from the rest of the boat's grounding systems (DC, AC, and lightning). There are several ways to do this. See, e.g., Stan Honey's excellent primer on grounding which West Marine published awhile back (Google it).

The reason for separating the RF ground from the DC ground has to do both with the corrosion potential and, especially, with the RFI potential. Both transmitting and receiving.

Lotsa ways to skin a ground cat :-) See, e.g., my post on RF grounds several years back: SSCA Discussion Board :: View topic - RF GROUNDS IN THE MARINE ENVIRONMENT

Bill

[btrayfors]

Kirk,

I'm based in Arlington, VA about a mile west of National Airport. My boat is at Capital Yacht Club, just across the 14th St. Bridge in DC.

Re: the arch, hard to say without knowing more about/seeing the boat. There are several ways to go. I have seen arches serve as excellent RF grounds, but others can be quite noisy...depends on configuration and what's mounted on them.

Whip antennas are sometimes the only solution for some cats and even some monohulls. I know of a new 57' Hunter with no backstay and a long boom which will probably have to go this route.

BTW, if you can fit a "rope antenna", it's very likely you could also fit an "alternate backstay" antenna made of more robust material, like s/s lifeline.

Bill

[Stevens 47]

In my particular case I had considered attaching the ground to bronze strut that thru-bolts to the hull using one of the bolts for my SSB ground...thats when I asked the installer. So I guess a safe bet would be to tap into the strut and attach a cone zinc that would be sacrificial then make sure that the strut is unbonded? Thanks Bill

[Paul L]

Originally Posted by Stevens 47

In my particular case I had considered attaching the ground to bronze strut that thru-bolts to the hull using one of the bolts for my SSB ground...thats when I asked the installer. So I guess a safe bet would be to tap into the strut and attach a cone zinc that would be sacrificial then make sure that the strut is unbonded? Thanks Bill

I prefer a through-hull over a strut. My rationale is that if you do end up with an electrolysis issue, it is far, far easier to get and install a replacement through hull than to get a matching strut for an older boat. Also, there is doc on the sailmail site that describes how to isolate the through-hull to reduce any chance of electrolysis from the ground connection.
Grounding I think it is the third figure labeled Figure 1.

Paul L

[limmer]

btrayfors I am thinking of running a separate ss wire from the mast to the push pit as a antenna, will this work or is just best to go with the insulated backstay and I also have rod rigging. also how many grounding points are required to the copper strip ie engine ,keel bolt, lifelines etc.. or is the more the better? cheers