Mast wiring

[Terry]

That wording about a channel through the 26M mast has been on the MacGregor website for five years now. Same for the large optional cooler that fits in the aft dinette seat, IIRC.

What about the big colorful racing spinnaker with the 6' bow extender that has been in the print for just as long, is it all talk and no action too?

[Shane]

Rich,

Thanks, that's exactly the type of info I was looking for; factoring in the different antennae gains. Considering how firm they sound on the 5 meter distance, the FCC & manufactures info all seems somewhat vague on these types of specifics.

As I read it, it looks like doubling the power (ie 50 to 100w) increases the safe distance by 1.4 (approx). So at 25w, I get 2.28m (Dividing the 3.2 by 1.4). A 50% duty cycle takes it down to 1.6m. Does that sound in the ballpark to you?

Regards,
Shane

Shane,

Maybe this chart will help:

Use the 2m/144MHz and assume 50 watts continuous, unc(uncontrolled).

Rich---Hamin' X---N7ZH

[Catigale]

Doubling the power decreases the safe distance by 1.4 of course, but you did the calc right for 25W.

A typical marine duty cycle is much, much less than 50%. If you talk 50% on the Hudson, the CG will come on and tell you to get off the air

[Hamin' X]

Shane,

That's pretty close to correct. Also, most antenna gain figures are wishful thinking. An antenna that is listed as 6 db gain is rarely more than 4. It is important to understand the difference between gain ratings, also. The third letter in the gain units is the important one. db(i) is rating compared to an isotropic (imaginary point source that radiates equally in all directions, spherically). db(d) is comparing to a half-wave dipole, a much more realistic figure. dbd is about 2.15 db less than dbi. If the third letter is missing, assume that the manufacture is rating in dbi, to inflate their gain. Also, a typical 25W VHF marine transceiver is only putting out 18-20 Watts. However, the chart is intended for a worst-case scenario and if you follow it's guide lines, all is well. Another point is, The FCC does not require us (Amateur Radio operators) to do an RF safety evaluation on VHF installations below 50 Watts and all mobile installations are excluded.

Rich---Hamin' X---N7ZH

[Catigale]

Mine was rated for db-Cooper - it came with 300k cash in the box

[Hamin' X]

Mine was rated for db-Cooper - it came with 300k cash in the box

[Captain Jim]

Nice Aft:

Ray,

I am getting ready to purchace a new VHF radio and antenna. I lke the way you have installed yours on NICE AFT, it seems to be a clean and simple solution. Have you experienced any regrets with your antenna mounting arrangement? If so, what would you change? What type of antenna do you have/recommend(3db,6db, etc)? Would appreciate your input or anyone else's from the forum. I only want to do this once. Like measure a whole bunch and cut/drill once.

Fair winds,

Jim

S/V BOLD VENTURE

[bubba]

Has anyone used the drilling thru the mast to put an anchor lite on the top of the mast? I was looking at a low wattage LED lite for the anchor lite.
I am already changing the interior lights to LED bulbs to reduce the wattage use.

[Catigale]

Just as an FYI this year I am putting a combined Nav light and anchor light on top of Catigales mast - this performs the function of the bow and stern light with a single bulb (one each for cruising and anchoring of course)

[RickJ]

Just as an FYI this year I am putting a combined Nav light and anchor light on top of Catigales mast - this performs the function of the bow and stern light with a single bulb (one each for cruising and anchoring of course)

I looked at the idea of a masthead tri-colour (both the bow and stern nav. lights were broken when I got my boat), but then I realised that the tri-colours were 10W minimum, whereas the Aqua-Signal 20 standard replacements are 5W each. The combined masthead lights are neat, but don't actually save any power over standard (unless you've found a 5W tri - I'd love to know which one if you have)

Anyway, by the time I'd put a wind transducer and VHF antenna on top of the mast, there was no room for anything else

Cheers, Rick

[Catigale]

Im actually less motivated by power savings, more so by wanting to be more visible. I think it is a 10W rating - LEDS are the way to go to save power of course.

[RickJ]

Im actually less motivated by power savings, more so by wanting to be more visible.

Which is OK until you start up the motor - the masthead tri-colour is then invalid, because of the need to show a white steaming light above the red/green lights. So you still need the regular lights at low level when under power!
Do you think nav. lights at the top of the mast actually do make a sailing vessel more visible? I've no opinion on this either way as I've never tried to make objective comparisons.

I think it is a 10W rating - LEDS are the way to go to save power of course.

LEDs rule! The only problem with nav. lights is the LED ones are stupidly expensive. I've been experimenting with replacement LEDs for other lights - the sort that are sold for cars at pretty good prices (esp. on eBay). I've found some good ones for interior lights, a deck light, and also one that works well in a Davis Megalight. But they aren't any good in the Aqua Signal nav. lights.

A lot sold for car use only emit usable light end-on, which is fine for the way most car lamps are made. For other purposes you tend to need light all-round, and there are some that have multiple individual LEDs pointing in different directions. These work pretty well, including in the Megalight, but the alignment is wrong for the nav. lights

Cheers, Rick

[Russ]

Do you think nav. lights at the top of the mast actually do make a sailing vessel more visible? I've no opinion on this either way as I've never tried to make objective comparisons.

My last boat had a tri-color light on top along with the anchor light. I think we used it maybe once.

I've got mixed opinions on this.

Surely in any kind of swells, higher lights are superior as lower lights will dip below the swells. However in close up situations, I'm leaning towards lower lights myself. I've been on the water close to another boat and didn't see their mast top tri-color. Well, actually I did, but mistook it for a light on shore or something. It was disorienting because I wasn't looking up there or expecting to see a light up there. This was in calm inter coastal waters. Offshore, the masthead tri-color wins.

Since the primary purpose of nav lights is to avoid collision, I'm now leaning towards good lighting close to eye level.

I'm toying with the idea of a masthead LED anchor light. Besides the fact that LEDs are priced way too high, I'm wondering if a small boat up close to me would be looking up there. With a blue hull at night, I'm probably a pretty dark object and my masthead light might look like a star.
I know of an accident where a Seadoo crashed into the side of a sailboat and went right through. Killed the driver and planted the Seadoo inside the boat.

Now, I'm thinking of a simple D cell battery powered clamp on anchor light that might also illuminate my deck a bit to make me more visible to fast moving boats at night. Shoot, if I had the power, I'd haul Christmas lights up the halyards to make us stick out.

[Catigale]

Thats an oft-missed point Rich, and thanks for reminding me of it.

Which is OK until you start up the motor - the masthead tri-colour is then invalid, because of the need to show a white steaming light above the red/green lights. So you still need the regular lights at low level when under power!

Correct. Of course, once under power, I have 200 Watts of alternator power, and energy conservation be d****d!!

[tangentair]

I have an 8 foot antenna that I mount to the rear mast support with 2 clamp on mast attachments and a short piece of pipe. Why 2, to correct for the angles of the mast support, one holds the short pipe and compensates for the backward slant and the other clamps on the short pipe and makes up for the inward slant -> cause she didn’t think it "looked nice" with just one.

The issue with the antenna atop the mast when stepping the mast often (or at all) is the connectors, soldering with dissimilar metals, corrosion, regular removal wear (and forgetting or loosing it) when trailering, or leaving it on and adding to the length/breakage opportunity.

As for visibility, when I am in doubt if my “low riding” running lights are being seen, I light up the main with the lantern on wide beam. I also saw a tricolor atop a J boat with milar sails AFTER it went by zipping by me in the dark. Close in I am just not focusing on anything that high