Raymarine "drain" wire question

[potter water]

I'd definitely get the vhf antenna up and away from the plotter. The cables are pretty much a non-issue themselves. But, depending on how well the antenna is matched to the radio and cables, there can be some emissions issue with the antenna that could at least temporarily affect your plotter. I don't think you'll burn it up with a transmission, but following the manufacturer directions unless impossible is the best way to approach any electronics installation. Besides, you've already mentioned that your ante is in a bad spot. If you move it up, your com distances will also improve. Antenna height is the major improvement you can make for com distance and it is sometimes dramatic even if you only gain a foot or two.

 

[Sunbeam]

I'd definitely get the vhf antenna up and away from the plotter.... I don't think you'll burn it up with a transmission, but following the manufacturer directions unless impossible is the best way to approach any electronics installation.

Understood. I actually hadn't noticed that spec until I was re-reading the manual the other day. I would HATE to damage the new plotter! And I hear you on following the recommendations - that was my impetus in starting the thread.

The only reason I have held off moving the antenna, is that moving it will require making holes in the cabin top. When I get radar (soon I hope), I may go with an arch and then that would take the VHF antenna too, so I'd have pointless holes in the cabin top that I just drilled :cry The location I have now also has some advantage in that I can put the VHF antenna up and down from the helm seat.

I guess what I really need to find out (cover your eyes, Colby, I'm asking questions again :wink) is whether the VHF antenna being near the plotter will cause nuisance problems that I can live with -- or will damage the plotter which I CANNOT live with! If the former, I would choose to just put up with it for awhile, until I decide what I *really* want to do with the VHF antenna. If the latter, I might just put back my Garmin plotter for now (which did not seem to be bothered at all), as I really don't want to move the VHF antenna and drill new holes just for something I might abandon in a couple months.

So... does anyone know whether the VHF interference with the new plotter would be "nuisance" or damaging? I won't be able to contact Raymarine for awhile as I have no phone reception here (have not had real good luck with their forum).

 

[potter water]

Really, no one is going to be able to knowledgeably answer that question for you better than your install manual unless they've been operating a duplicate radio, antenna, wire routing and plotter. The manufacturers spend a lot of money on emissions and susceptibility issues testing associated with their digital equipment. So, they've determined, according to your install manual that you shouldn't install the way you'd like to convince yourself that you can. So, the simple answer is if you don't move the antenna, you may damage or have trouble with your equipment.

You can do whatever you want and run to the manufacturer warranty dept. if it causes grief. But that wouldn't be nice.

Now, if you can get an antenna extension mount that will move the radiating part of your antenna up and away from the plotter over 3 feet, you may be good to go. You can, I'm pretty sure get an extension mast.

 

[Captains Cat]

Sunbeam said:

"PS: I had a slight puzzlement when I went to strip that tiny wire and, no matter how careful I was (of course the 22 gauge stripper was too large, so I was using a pocket knife) I kept cutting off the whole thing. After a couple of times of that I knew something was up and looked closer: Aha - the wire insulation extended about 2" past the end of the wire, so I was "stripping" just insulation with no wire ever in there. Duh! I also found that I could just "pull back" the insulation vs. cutting it off (once I started with a fresh cut that had both wire and insulation in it). It's very rubbery insulation and moves easily along the wire."

Just a strange thought [british]. Maybe it's called a "drain" because that's where the water runs if the dome leaks? :roll: . The water wouln't leak through that great insulation... :disgust

Enough, I'll be glad to start installing my new Garmin stuff in a month or so.

Charlie

 

[Sunbeam]

Really, no one is going to be able to knowledgeably answer that question for you better than your install manual unless they've been operating a duplicate radio, antenna, wire routing and plotter.

Fair enough. I do know of one other 22 that just installed an A98 and that I think may have the VHF antenna in the same place (was put there by C-Dory on many 22's). It's actually the boat with a new A98 that I tried out before deciding to buy one. However, I don't think they read the forum (I have sent an e-mail). I just thought someone else with a 22 that has the same antenna placement might have a Raymarine MFD and might have found out about the same issue (someone with phone reception!).

So, the simple answer is if you don't move the antenna, you may damage or have trouble with your equipment. You can do whatever you want and run to the manufacturer warranty dept. if it causes grief. But that wouldn't be nice.

I hear what you are saying. But here's the thing: I think we all know of cases where a manufacturer specs the best possible scenario, and in many cases it's either not possible to achieve on a given boat, or would be a hardship. Sometimes by understanding the "why," we find out that we can live with something as-is long term, or short term (without damage). Other times it's best to do exactly as they say (or, say, decide to buy a different piece of equipment that suits the boat better). I just want to find out more so I can make my best decision. And I'd like to use the new MFD when I launch tomorrow if I can. I won't be able to relocate the VHF antenna before then.

I'm sorry if this thread has given the impression that I'm trying to "get away with something." Perhaps I need to improve my communication skills. I don't intend to "run to the warranty department" for a claim for something I had caused on purpose. I try to be nice.

Now, if you can get an antenna extension mount that will move the radiating part of your antenna up and away from the plotter over 3 feet, you may be good to go. You can, I'm pretty sure get an extension mast.

Hmm, interesting. My antenna is already of a type that has a plastic tube base section and then the (bare) wire part is raised up somewhat. I wonder where the radiating part starts? This is what it looks like. Hmm, hard to find a good photo, but this shows most of it. The upper tip is off to the right, and is basically the same as what you see. The part at the lower left attaches to a 5" long adapter which then attaches to the mount. I'll put up some better photos after I get them ready to post.

Okay, here are a couple from my actual boat, inside and out.

ust a strange thought [british]. Maybe it's called a "drain" because that's where the water runs if the dome leaks? :roll: .

This is an MFD, so it's all inside the boat.

 

[colbysmith]

Hi Sunbeam, please don't take offense to my KISS statement. Just sometimes we need to keep things simple. (Not to be confused with JRTFM. All terms I learned in the military...not directed towards the person, but rather the situation!) Nothing wrong with asking lots of questions. I do the same, and when not, do a lot of lurking in the forum to see what I can learn. But I think sometimes the manuals are written for all installations, from simple boats like ours, to mega yachts. Lawyers come into play with a lot of the writing. I have all my wires ran pretty much together from the stern to the bow. So much for keeping distance. Damn near impossible in any size vessel! But I do follow the restrictions (well except for my compass..again pretty much impossible on a small boat), when it comes to distance between antennas and equipment. A shielded cable will have some silver foil or saran wrap like material around the inside wires. As for the "drain" wire, I pretty much treat it like the ground wire in house wire. I understand what those that know electronics are saying about the RF dump, but haven't had any issues of my own by connecting the drain wires to the negative post on my terminal blocks. I'm sure warranties come into play also if one doesn't follow the instruction manual precisely, but I think reasonable can be fought for in the end. Ok, off to the lake to try out my new installation.

 

[potter water]

The wire is the radiating element. The other part contains coils for what looks like your quarter waver radiating element. In any case, all you have to do really, is get the "wire" bit up three feet away from your digital stuff. Check with west marine or other supplier on an extension mast for your antenna. That should reduce your risks by 90% and give you better com to boot.

 

[Sunbeam]

Colby,

I hear you, but.... then look at the VHF scenario. Is that "ignorable"? I don't know, and haven't been able to find info from anyone who ignored it and had no problems (or ignored it and did have problems). As potter water says, it's best not to ignore the manufacturer's recommendations. But then as you say, it's not always possible to keep everything ideal on a small vessel. Trick is knowing (or finding out) when you can fudge and when you can't. That's what I was trying to find out now, about the VHF antenna.

The wire is the radiating element. The other part contains coils for what looks like your quarter waver radiating element. In any case, all you have to do really, is get the "wire" bit up three feet away from your digital stuff. Check with west marine or other supplier on an extension mast for your antenna. That should reduce your risks by 90% and give you better com to boot.

Okay, thanks. However, I won't be able to do that before I launch at Powell. This is why I wondered about damage vs. "inconvenience" interference: I'm not in a place brimming with marine supplies. And I hate to miss out on boating here. I had missed the VHF warning in the manual before coming here (my Garmin had no issues being that close to the VHF - not sure why the Raymarine is more fragile that way). I hate to just give up the trip if I don't have to. But if I put my Garmin back in I will not have reliable depth. Boo! I hate annoying guess-choices :crook

I just figured it might be like Colby said: An "ideal world" type of thing I could get by without doing for now. But it sounds like it's not that simple and could damage the MFD. That would be a bummer.

At any rate, now you know why I'm trying to not follow the manual to a T, if it's acceptable.

 

[potter water]

You pays yer money and yous takes yer chances. I actually think you'll be okay, but now you understand some of the issues and can make an intelligent choice. Another is to use only your mobile back in the cockpit. Monitoring 16 on the permanent mount, but xmitting from your mobile. of course, mobile is not as great for distance, but I've found it isn't very often that my Icom mobile vhf doesn't do the job on the lake.

Wish I was still on the lake. My trip for the gathering wasn't close to long enough. Great weather coming up for you as far as I can tell.

 

[Sunbeam]

You pays yer money and yous takes yer chances. I actually think you'll be okay, but now you understand some of the issues and can make an intelligent choice.

As you say, the main thing is knowledge -- I just like to make informed choices.

Another is to use only your mobile back in the cockpit. Monitoring 16 on the permanent mount, but xmitting from your mobile. of course, mobile is not as great for distance, but I've found it isn't very often that my Icom mobile vhf doesn't do the job on the lake.

I don't have a handheld VHF, but then as you know, there is not much reason to transmit on Powell (very little line of sight). I'll probably just go with it, and try not to transmit (or perhaps turn off the plotter if I have to). I could easily imagine no need to transmit at all given that I won't be trying to find the gang. Of course I will if I need to.

Wish I was still on the lake. My trip for the gathering wasn't close to long enough. Great weather coming up for you as far as I can tell.

I wish you were still here too! Would be fun to have some fellow C-Brats to boat with. I held off launching (and stayed land camping) because of the weather I could see was coming through yesterday and today. And it was, indeed, very stormy yesterday. There were times I couldn't see the lake or any of the cliffs due to blowing rain! There was also quite a bit of lightning and thunder. Went on pretty much all day and evening. Today has been sunny but with at least a half dozen intense "thunderboomers" passing through with wind and rain. At one point there was a fantastic, double, full-arch rainbow over the lake and hills - that was pretty cool! There are still "active" looking clouds moving about but I believe it's on the way out.

I was thinking of Thataway (and any other Brats that might still be out on the lake); hopefully they were hunkered down if still out.

Seems that now the weather pattern has changed from really hot days, to very pleasant mid-70's. Looks like tomorrow will begin a nice, settled, sunny period again (fine by me). Anyone want to come back to the lake? :smile