AIS, VHF, WIFI, SSB Antenna Location - Page 2

Beausoleil · 05-10-2009, 17:07

Quote:

Originally Posted by s/v Jedi

I think you're all a bit silly. That Comar switch is a fine product by itself, but it's also $350.- which is much more than the cost of 2nd VHF antenna on the radar post/arch/whatever and that 2nd antenna is still the better solution.

Truer words were never said, Nick, but - there's always a "but":

For those cruisers who aren't very adept at climbing the mast or climbing into a lazarette, pulling coax, crimping PL-259 connectors, etc. - $350 is chump change compared to the cost of hiring the local boatyard to do the installation of a second VHF antenna and the coax at $95/hour. For you and me - I'd go for the second antenna without even thinking, but to the average cruiser it could be a viable choice to go with the Comar auto-switch.

YACHT TARENTELA · 12-10-2009, 06:27

One thing to consider, and this happened to me on a previous boat, is to have your cockpit VHF antenna mounted on a stern rail and your main Nav station VHF antenna at the masthead. In an emergency when the mast comes down and you're trying to be rescued you have a means of communicating with other vessels. I actually used the VHF with the stern rail antenna most of the time and was ok with the range and reception.

GordMay · 12-10-2009, 07:44

Any opinions on the cheaper Shakespeare antenna (co-ax) switches?
- Manual CS-2 (<$50)
- Automatic AS-2 (< $90)

Are these re-labelled “MJF” selector switches?

s/v Jedi · 05-10-2009, 20:43

Jon,

I'm sorry to say that you might be right. I sure hope that cruisers who can't do that simple project or are just unwilling to do that (would hire someone to do it for them) have big heaps of dollars before setting out cruising because installing a vhf antenna is about the easiest job.... and many jobs _will_ come up....

I notice a lot that cruisers first tell me "they" are going to do this or that project on their boat and finding later that they meant hiring someone to do it.... and later complain one should do everything themselves to get it done right.... until the next time when they hire again.

cheers,
Nick.

colemj · 12-10-2009, 08:27

We use the CS-2 with no problems. It connects the AIS and the 2 meter ham to the same antenna. No problems since we don't use them at the same time and only want to share an antenna. It looks exactly like the MJF switch.

Mark

sandy daugherty · 12-10-2009, 10:03

I don't believe there is much added benefit to mounting an AIS B antenna higher that 14' to 18' off the water: a handheld VHF has more than twice the power and is limited to less than a dozen miles with line of sight. Vessels with short AIS antennas mounted on the pushpit report receiving AIS positions at 26 miles, or almost an hour warning in a worst-case head-on scenario.

Your GPS antenna should be mounted as low as possible with a relatively clear sky view on a sailboat. The cabin roof is the best bet. The motion of the antenna when mounted higher causes problems. Note that it should have a clear view down to the horizon, as more widely separated satellites yield better triangulation. It you also mount a satellite radio antenna, it needs a clear view at low angles too.

I, too am pleased that a whip is a good ssb antenna, even though I have an insulated backstay. The verticality issue is of less relevance with an SSB, because it is not line of site, strictly speaking.

I have an omni-directional wifi antenna with exceptional range, but that's still no more than 5 miles. The only reason to raise it would be to see over another boat or over a breakwater. The added height only exacerbates the problem of powering the antenna. Mine is on the same (fiberglass) pole as my AIS antenna.

12-10-2009, 07:44	#3
GordMay Registered User Join Date: Mar 2003 Location: Thunder Bay, Ontario - 48-29N x 89-20W Boat: C.L.O.D. (Cruiser Living On Dirt) Posts: 12,576	Any opinions on the cheaper Shakespeare antenna (co-ax) switches? - Manual CS-2 (<$50) - Automatic AS-2 (< $90) Are these re-labelled “MJF” selector switches? __________________ Gord May ~~_/)_~~ (Gord & Maggie - "Southbound") "If you didn't have time/$ to do it right in the first place, when will you get the time/$ to fix it?"

12-10-2009, 08:27	#5
colemj Registered User Join Date: Oct 2005 Location: Heading South Boat: Manta 40 - Reach Posts: 497	We use the CS-2 with no problems. It connects the AIS and the 2 meter ham to the same antenna. No problems since we don't use them at the same time and only want to share an antenna. It looks exactly like the MJF switch. Mark __________________ www.svreach.com

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12-10-2009, 06:27	#2
YACHT TARENTELA Registered User Join Date: Aug 2009 Location: NOVA SCOTIA CANADA (SUMMERS) Boat: HUNTER PASSAGE 450 "TARENTELA" Posts: 6	One thing to consider, and this happened to me on a previous boat, is to have your cockpit VHF antenna mounted on a stern rail and your main Nav station VHF antenna at the masthead. In an emergency when the mast comes down and you're trying to be rescued you have a means of communicating with other vessels. I actually used the VHF with the stern rail antenna most of the time and was ok with the range and reception.

05-10-2009, 20:43	#4
s/v Jedi Registered User Join Date: Feb 2009 Boat: Sundeer 64 - Jedi Posts: 1,519	Jon, I'm sorry to say that you might be right. I sure hope that cruisers who can't do that simple project or are just unwilling to do that (would hire someone to do it for them) have big heaps of dollars before setting out cruising because installing a vhf antenna is about the easiest job.... and many jobs _will_ come up.... I notice a lot that cruisers first tell me "they" are going to do this or that project on their boat and finding later that they meant hiring someone to do it.... and later complain one should do everything themselves to get it done right.... until the next time when they hire again. cheers, Nick.

12-10-2009, 10:03	#6
sandy daugherty Registered User Join Date: May 2008 Location: near Annapolis Boat: PDQ 36 "Page 83" Posts: 770	I don't believe there is much added benefit to mounting an AIS B antenna higher that 14' to 18' off the water: a handheld VHF has more than twice the power and is limited to less than a dozen miles with line of sight. Vessels with short AIS antennas mounted on the pushpit report receiving AIS positions at 26 miles, or almost an hour warning in a worst-case head-on scenario. Your GPS antenna should be mounted as low as possible with a relatively clear sky view on a sailboat. The cabin roof is the best bet. The motion of the antenna when mounted higher causes problems. Note that it should have a clear view down to the horizon, as more widely separated satellites yield better triangulation. It you also mount a satellite radio antenna, it needs a clear view at low angles too. I, too am pleased that a whip is a good ssb antenna, even though I have an insulated backstay. The verticality issue is of less relevance with an SSB, because it is not line of site, strictly speaking. I have an omni-directional wifi antenna with exceptional range, but that's still no more than 5 miles. The only reason to raise it would be to see over another boat or over a breakwater. The added height only exacerbates the problem of powering the antenna. Mine is on the same (fiberglass) pole as my AIS antenna.