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ContinuousWave: The Whaler GAM or General Area
VHF Antenna Mounting Location; Electrical Panels
|Author||Topic: VHF Antenna Mounting Location; Electrical Panels|
posted 06-12-2000 03:05 PM ET (US)
jimh--I saw the picture of your console.(nice job) Where did you mount your [VHR Marine Band radio] antena? Do you have an eight-foot long? Someone told me I could get a short whip antenna, but I usualy fish offshore and wanted to get the best range. Do you have a picture of your ant. you could post? Also how did you instal your wiring for your accesories? I was going to run a fused pos. wire to a fuse block mounted under the console and run my accesories from the fuse block. Is this how you did it? If so what gauge wire did you use for the pos. & neg. wires going to the fuse block? I want to run a uhf radio, gps, fishfinder, and running lights, maybe a radio off of the fuse block.
posted 06-12-2000 09:45 PM ET (US)
Rick: I am about to begin rigging my boat, and have many of the same questions that you do. While I would like to have answers from other forum members, I am also doing research. There are several good books on boat electrical systems and electronics. I got one from the library, and the West Marine catalog has some too. One thing to consider, if all of your electronics are run through a common fuse, then a problem with one will take out all. This is why my VHF will be on its own fuse or breaker.
posted 06-13-2000 12:41 AM ET (US)
The electrical "panel" on my boat is home made and quite compact. Here is how it works:
At the battery, a waterproofed in-line fuse (20A) protects the positive lead, no fuse in the negative lead.
From the battery a length of 12ga. red/black cable under white cover runs along the side of the boat, along with the engine remote cable, the shift cables, and the steering cable, under the console and terminates at a terminal block with about 6-8 rows of terminals, each with two screws. Little jumper clips mulitply the postive and negative battery connections so there are two or more rows of the raw battery postive and negative.
The VHF Radio and the Depthsounder are connected directly to the battery terminals here; each of these has its own ON/OFF switch built into it. The radio has its own in-line fuse; I think the depthsounder does, too.
A dashboard mounted switch controls the running lights, with a 14 ga. Red/Black under while cover cable running back to the stern where it connects to the running lights terminal block (OEM) on the port stern wall of the cockpit. The running light circuit also feeds the tachometer lighting circuit, so it is illuminated whenever the running lights are on. There is an in-line fuse protecting this circuit. It is installed between the battery positive at the dash terminal block and the switch. This is fused at about 5A so that it will blow before the main 20A, should something short circuit in the running light circuit. The main fuse wont be tripped.
I used the WEST Marine Ancor brand cable for these runs; it is nice cable and quite flexible.
The GPS runs off its own AA Batteries, as this is simple and I have basically an infinite supply of slightly used AA batteries. Isolating the GPS receiver from the battery on the boat prevents any problems with alternator/magneto whine getting into the radio and causing interference.
The radio antenna mounting has been a problem! I have a low-cost 8-foot VHF marine band antenna which I leave lying along side the railing and the seat risers on the starboard side of the boat. Lying down like that it doesn't work as well as standing up, but it usually gets the weather stations just fine. I can also transmit on it like that for calling the marina from a short distance or another boat nearby. When it is down like that I use only 1 Watt (LO) of power.
If I were miles offshore and needed to raise someone on the radio, I would just fish the antenna out of the slot along the side of the boat and hold it up by hand to get better results.
Before I had the bimini installed, I used to use a little piece of wood with a mount attached to it which I would C-Clamp to the seat. This worked fine, but now with the bimini top installed and up, you cannot mount the antenna base at either seat and get a clear shot up--the top interferes.
So I am still looking for the perfect place to locate the antenna mount. Only the transom looks likely, but I don't want four extra holes in it.
I have been thinking about developing my own compact antenna which would mount on the top of the outboard motor cowling (metal!). The flat top of the outboad is really about the best ground plane on the boat (all fiberglass otherwise).
Another idea I have had involves using the stern light pole as part of the antenna.
By the way, I have quite a bit of experience with antennas and transmitters, having worked as a Broadcast Engineer for over 25 years, and prior to that I was Associate Editor for a rather well-regarded radio techincal journal. Antennas have always been a topic of intense interest to me.
All the "gain" of any antenna comes from compressing the radiation into narrower beams, but at sea the motion on a boat can produce a situation where really high gain antennas don't result in improved transmission or reception. The narrow beam of the antenna is rocked up and down by the boat's motion.
So I am not a fan of really long, high-gain antennas for boats.
posted 06-13-2000 09:33 AM ET (US)
I am struggling with the same problem. I decided to try this:
I have a piece of 1/2" thick 16"x16" steel plate with a center hole. I mounted a standard 8'mast and located it in the rear corner of the boat. The weight of the plate keeps it upright and my hope is that it will provide some sort of ground plane. I took some soaker hose from the garden and split it lengthwise to make a bumper around the plate, so as not to damage the boat. I have pictures if anyone would like.
posted 06-13-2000 08:54 PM ET (US)
Jim: thanks for the detailed info. Now I realize that all of the research in the world can't compare to learning what other people are doing. Like the difference between when I was in Veterinary school, and practicing in the "real world".
posted 06-14-2000 12:12 AM ET (US)
On our montauk I've mounted the vhf and the loran on port/st.bd. of the front rail at the vertical support, well in front of the bimini and fairly high. It is monted by sanwiching wood blocks routed out to a little less than 180* of rail diameter, on one side is a s.s. plate and the other an antenna mount. The biggest pain is the cable routing: under the ice-chest across the froor (under a thick rubber mat about 12x24 and up the face of and across the bulkhead near it's top edge, attached with self adheasive cable clips. Works pretty well, masts lay down between rail and hull when released for trailering etc.
posted 06-14-2000 12:25 AM ET (US)
The mounting suggested by SR in his post is a good idea, but I couldn't do it in my installation because my Bimini Top rails are mounted to the gunwales, so the antenna would not have a clear slot to raise and lower into.
Now that I've seen the Mills & Co. canvas, I should have either gone for one of their bimini tops ("Sun Top") or re-configured the catalogue-brand top I bought to mount like the Mills.
Ah, live and learn. The upside is that we don't usually get THAT far offshore in a 15-foot, single engine boat that we need a long-range radio.
posted 06-14-2000 12:31 AM ET (US)
Also, I wanted to comment that I bought the "marine grade" ANCOR wire, even though it was rather expensive.
ALthoughh I work daily with all kinds of wire and electrical vendors, I really could not find a cable as nice as the ANCOR product that I could get easily from my distributor. So I just figured, the heck with it, I was only buying a few feet of wire, and I paid the retail "marine" price for it.
The other things, like terminal blocks and crimp lugs, etc., are pretty standard items and can be found through many sources, although again it may not be worth shopping all over to save $3.00 over the West Marine price.
posted 06-14-2000 12:35 AM ET (US)
Regarding mounting of antennas on Whalers, that's what the rails are for! (also for fishing rod holders). To avoid drilling holes in the hull, I have always used the clamp-on SS ratchet style antenna mounts, about $35 at most stores. On a 15 or a Montauk, the starboard side rail, near the stern just beyond the 90 degree bend as the rail becomes horizontal, works well. These rails are always outside of any Mills canvas installation, so the canvas won't interfere.
The ratchet allows you to lay the antenna down when not in use.
posted 06-14-2000 10:18 PM ET (US)
One problem for me: my nauset has no rails. I'm thinking of adding some low handrail type rails, to grip when gaffing a big fish. Not sure how to secure them. That's a topic for another day. In addition, I don't want to interfere with the potential need to walk a fish around the boat. Eric
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