RADAR, A/P, Refrigeration, Etc.

I'm well into a refit on a 1976 Gulfstar 36' MKII Twin Trawler. Electrical is just about done (DC and AC upgrades). Next is plumbing (I'm pretty set on what I want), and then on to other systems. Input/experiences will be greatly appreciated.

1 – RADAR – Toying with mounting on an EDSON pole but also mounting the dome in front of and just below the upper helm. I’ve seen that done many times on other boats and I know the new domes don’t pose a health threat. But what would that do to the coverage to the stern? I very much like seeing if something is coming up behind me. Would it be able to “see” through the upper helm, additional bimini supports (sun deck) and such or would that degrade things?

2 – Satellite TV – I know the smaller KVH, Itellian, Raymarine domes will all work fine state-side, but we’re going to (hopefully) be into the Exumas. Checking coverage charts I don’t think the small domes are going to work well there. And the larger domes are heavy and very expensive. I’m tempted to go with the TITV (Track-It TV) PVC pipe thing as it can take up to a 32” dish. They don’t work well underway though.

3 – 12v or 110v refrigerator – I was originally planning on using the 36" 110v unit that was on the boat. A friend of mine who’s cruising right now runs a 110v refrigerator off inverter and has no problem with it. But my contractor really suggests 12v. I have an inverter-charger fully installed, but what if it goes up and we’re in the middle of nowhere? We’re installing a backup Pro-Mariner 40-amp charger for such a situation but I’d have no inverter.

4 - Autopilot. Twin inboard diesel. Hydraulic steering. I installed an AP on my powercat (manual cable steering with outboards) but am just starting research on a system for this boat.

Thanks!

mixman said:

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1 – RADAR – Toying with mounting on an EDSON pole but also mounting the dome in front of and just below the upper helm..!

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Aiming for the gonads? Have my radar far away from my exposure!

Kurt I'd echo (no pun intended) the previous post regarding placement of your radar antenna. Although the new broadband radars pose no significant radiation hazard any microwave radar is going to transmit straight through you in that lower position. It will probably still be able to see returns from astern but anything blocking its path will attenuate the signal and reduce the range available,

Cheers

Brett

I like my 'nads as they are. I will be putting the radar dome high on an Edson mount. The HD radar on our cat is a few feet above our Bimini so it will be that way on our trawler too. Thanks!

I got a lot of criticism for where I placed my radar on my previous boat however I had no radar display on the flying bridge as I reasoned whenever I actually needed radar (inclement weather) I'd be at the lower helm anyway.

1. Worries about marine radar, even the older type units, causing harm to your body are over blown to say the least. Between the low power and modulation of a marine radar there is little worry of harmful effects unless you were going to sit if front of it 24/7 for years from what I've read.

2. You're going to need a large dome if you want TV down in Gtown. And you'll start losing channels sooner then that. You might be able to change the LNB and get the Galaxy satellite.

3. Just have a small backup inverter just for the fridge. But straight 12 volt should be more efficient in the long run.

4. Pretty much any brand of AP is good these days. But it's hard to beat Simrad.

Isn't there a way to blank the transmission of the radar, where it won't be trying to cook you on radars mounted on flybridge front.

Rebel112r said:

Isn't there a way to blank the transmission of the radar, where it won't be trying to cook you on radars mounted on flybridge front.

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Yes....you create a zone where there is no transmission so mounting it right in front of you is no danger at all. As long as the RADAR has that feature which used to be pretty common....haven't looked lately.

The downside is you don't see right behind you with the RADAR.

A genuine DC reefer will discharge your house batts slower than a cheapo box store unit with an inverter.

As you will be learning buy the house batts at Sears or Wallmart where they are very lax on returns.

I installed a Track-it-TV unit I purchased used for $250. I installed it in a location that made it easy to remove the dish and to adjust the elevation. I remove the dish while underway and while the boat is left unattended for any time. Heavy winds or cruising at 18 kts would weaken the attachment fittings. The 24" antenna I used creates a lot of drag.

I bought the unit primary for cruising the ICW last fall. It worked mostly well but I found the power requirements for use at anchor required the use of the generator. Not for the tracking antenna but for the sat box and TV. So we used it mostly while at marina's. One major flaw in this unit is because of a very short wire connecting the rotating mast to the stationary support, the antenna would only rotate about 180 deg before I had to re-position the dish.

There is a learning curve required to use this setup. You must find the sat in both azimuth and elevation every time you use it. And the sat box must be reset each time it receives power to get programming. It took a while for me to figure all this out but once I learned it, it went pretty quick.

I did this on the cheap knowing I probably wouldn't need it long term. For this it worked well, but if you want a permanent setup, get a used dome unit.

I can't imagine anyone with a boat the size of most of us here on TF watching TV while underway.

Rebel112r said:

Isn't there a way to blank the transmission of the radar, where it won't be trying to cook you on radars mounted on flybridge front.

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Contrary to the popular misconception, marine radars are not rotating microwave ovens.

On radar, the issue to me is, not of the safety factor, but the usefulness. Higher is better for range. Not knowing what's in your FB console or behind it or how it is constructed, hard to comment on rear vision, but a lot of old Hatteras motoryachts had the radar mounted on the brow over the lower helm. But that is still a good 14 or 15 feet above the waterline. I had my open array up on an arch.

As for TV, even a Track It will be very sketchy to worthless in the islands; I'd give them a call (very nice folks) and discuss. My advice is stock up on DVD's or load movies on some other device.

Recreational marine radars don't have the power output to do damage unless you eat the parts.

The SPS-48C 3D air search radar we used on the Constellation was another thing altogether- it could burn thru chaff and focus its output like a laser beam. Nasty stuff!

A/P- the Raymarine Evolution is fantastic- easy to install and integrates with all modern Raymarine MFDs.

Track It is tempting as I've had a competing product on my cat for years with good service. AzTrax is no longer made but worked well for me through the Abacos with only a 14" dish.

There are differences in opinion on whether 110v refrigerators are good bets for cruising boats. I have three concerns with them ( had them for 14 years). 110 v uses more power which means more generator time and more battery cycles. Battery life is dependent in part on the number of charge /discharge cycles. Also if the inverter or generator goes down you are out of refrigeration. With 12v reliance on the inverter is not an issue.

The exumas are not well equipped to repair either a generator or an inverter. Nor can you replace them there easily. It is best to be prepared for breakdowns.

1. Radar - agree with others
2. Sat TV - not much I can add. Had FMTV and it was too "ghetto" for my wife.
3. Fridge - Inexpensive AC on inverter plus backup Engel / Edgestar.
4. AP - just went thru this on separate thread. I have Raymarine AP and MFD as well as Garmin MFD, and Coastal Explorer on laptop. Hydraulic pump sizing is critical, the AP must support that current draw, any N2K AP should work.


Keith

Capt.Bill11 said:

1. Worries about marine radar, even the older type units, causing harm to your body are over blown to say the least. Between the low power and modulation of a marine radar there is little worry of harmful effects unless you were going to sit if front of it 24/7 for years from what I've read.

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You may be right, and your logic is compelling, but I would discourage anyone from accepting that conclusion without independent verification. The stakes are too high. FWIW, my Furuno radar manuals warn of health hazards of exposure, but that may just be from the legal department.

MYTraveler said:

You may be right, and your logic is compelling, but I would discourage anyone from accepting that conclusion without independent verification. The stakes are too high. FWIW, my Furuno radar manuals warn of health hazards of exposure, but that may just be from the legal department.

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From Furuno's tech training seminar (which I attended for 3 years and asked that very question)...

How damaging is small boat radar say 4kw and less....

The instructor said you would have to have your head in the dome or within the sweep of an open array to even begin to worry. Not only is the pulsing or the radar reducing the radiation, the sweep is reducing it greatly.

When close to the dome, sort of like putting your microwave on 5% power...that's the amount of time you are getting pulses (not full power).

So unless you want the same info right from Furuno...

The radiation hazard caution is probably the same for anything that can cause radiation used incorrectly or when working on it or refocusing the beam by improper placement....not normal install and proper use.

psneeld said:

The radiation hazard caution is probably the same for anything that can cause radiation used incorrectly or when working on it or refocusing the beam by improper placement....not normal install and proper use.

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My boat has two radars. A 6kw is mounted on an arch above the tower. It is not physically possible for anyone onboard to get within the radar's beam unless they climb above the tower's seating/standing area. The second radar, 25kw, is mounted on the hard top above the fly bridge. Anyone climbing the tower ladder must pass through its beam, from a distance of about 6 feet. If you are quick, you can time the ascent so that it misses your head or gonads, but not both. So, some of my guests won't go to the tower unless the radar is shut off first. One time, I shut if off long enough for a buddy to go up to the tower, then I turned it back on. After a few hours, I realized that I hadn't seen my buddy and found that I had trapped him in the tower -- he didn't want to come down while the 25kw was spinning. And unfortunately for him, he couldn't figure out how to work the hailer in the tower. I think I will tell him that the consensus of opinion is that he doesn't need to worry about that little exposure, especially since he is beyond his reproductive years.

American supposedly get 100 times random radiation that most undeveloped nations get.


Airline personnel also get a much higher dose of solar radiation....


You friends need to get an education.

boatpoker said:

I got a lot of criticism for where I placed my radar on my previous boat however I had no radar display on the flying bridge as I reasoned whenever I actually needed radar (inclement weather) I'd be at the lower helm anyway.

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I use radar whenever operating the boat. Need to continually educate myself on what one sees on the screen versus eyesight.

markpierce said:

I use radar whenever operating the boat. Need to continually educate myself on what one sees on the screen versus eyesight.

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With over 20,000 hours in my log and an 11 week radar/arpa /marpa course certificate under my belt I'm quite comfortable using it only when needed.

boatpoker said:

With over 20,000 hours in my log and an 11 week radar/arpa /marpa course certificate under my belt I'm quite comfortable using it only when needed.

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As you know, as a licensed professional there is no excuse for an incident with your radar not on and being used for collision avoidance. No marine accident has 100% blame on one party (or at least VERY few). You would have some "Splainin" to do if a cigarette boat full of bimbos slammed in to your boat and your radar wasn't activated. Makes no sense, but thats the world we live in. You will be held to a higher standard because of your radar/arpa/marpa.

Greetings,
I'm with Mr. mp on this one. Radar on in all weather to correlate what I can see on the water with the corresponding return on the screen.

Regardless, during daylight hours I primarily rely on eyesight. Many things don't show up on radar.