Quote:
Originally Posted by Boulter
Hi:
My VHF has PA and Fog signals. I mounted the horn speaker on the solar panel arch at the aft end of the cockpit on my Tanzer 22. My boat is so small it wasn't clear where I might mount it more forward without it being a PITA in some way. Plus it was not clear why I wanted the audio to be directional pointing forward, so my mount allows the speaker to rotate through 360%.
Boulter |
Yes, mine does too. In order to sound the horn, you have to get out a pair of reading glasses and navigate through three sub-menus. By which time the
collision will have already happened. Such great engineering!
I need a big red button that I can push in a split second. At my old marina, hipster douchebag kayakers would glide right out into the very narrow channel without looking at all. (There was a rental shed at the end of the
dock.) I'd really, really like something that would soil their drawers. Now, in the summer time, I have to pass through an area with hundreds of barely-controlled kite boards and windsurfers. But I'm not sure they could even hear a horn - or know what to do if they did hear one...
BTW: The frequency of the horn is supposed to be proportional to the size of the boat. So that you have some information about what is coming at you out of the dark/fog. I seem to
recall that there is actually a setting for that in the
radio. Although I find it hard to imagine that a vessel over 75m would be using a consumer-grade Standard Horizon set.
1. Whistles
(a) Frequencies and range audibility The fundamental frequency of the signal shall lie within the range 70-700Hz. The range of audibility of the signal from a whistle shall be determined by those frequencies, which may include the fundamental and/or one or more higher frequencies, which lie within the range 180-700Hz (+/-1%) for a vessel of 20 meters or more in length, or 180-2100Hz (+/-1%) for a vessel of less than 20 meters in length and which provide the sound pressure levels specified in paragraph 1(c) below.
The range of audibility of the signal from a whistle shall be determined by those frequencies, which may include the fundamental and/or one or more higher frequencies, which lie within the range 180-700 Hz (+/- 1 percent) and which provide the sound pressure levels specified in paragraph 1(c) below.
(b) Limits of fundamental frequencies. To ensure a wide variety of whistle characteristics, the fundamental frequency of a whistle shall be between the following limits:
(i) 70-200 Hz, for a vessel 200 meters or more in length;
(ii) 130-350 Hz, for a vessel 75 meters but less than 200 meters in length;
(iii) 250-700 Hz, for a vessel less than 75 meters in length.
(c) Sound signal intensity and range of audibility A whistle fitted in a vessel shall provide, in the direction of maximum intensity of the whistle and at a distance of 1 meter from it, a sound pressure level in at least one 1/3rd-octave band within the range of frequencies 180-700Hz (+/-1%) for a vessel of 20 meters or more in length, or 180-2100Hz (+/-1%) for a vessel of less than 20 meters in length, of not less than the appropriate figure given in the table below.
Length of Vessel
in meters 1/3-octave band level at 1 meter in dB
referred to 2 x 10-5 N/m2 Audibility range
in nautical miles
200 or more 143 2
75 but less than 200 138 1.5
20 but less than 75 130 1
Less than 20 120*1
115*2
110*3 0.5
*1 When the measured frequencies lie within the range 180-450Hz
*2 When the measured frequencies lie within the range 450-800Hz
*3 When the measured frequencies lie within the range 800-2100Hz
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