What type of antenna is this?

[ka4wja]

RB, Wotname, smac, et al,
Until we get more info, RB needs to know that so far we are guessing...


1) smac, as I wrote, I also think a DGPS-beacon antenna is a possibility....and/or also a NAVTEX receive antenna?

Originally Posted by smac999

Looks one an old dgps antenna. To pick up ground station corections.

2) Wotname, I suppose one VOR antenna would do? I've just always seen them in pairs...
But, truth be told, since this is a 2004 cruising cat, unless the previous owner was a pilot and had some weird ideas, it's highly doubtful these are VOR antennas....(I haven't seen VOR antennas on a boat in many decades, and these were all installed in the 1970's or 80's)

Originally Posted by Wotname

FWIW, a VOR antenna would usually be horizontally polarised and no need for them to be paired (on a sailboat that is) - AFAIK.

3) RB, you're welcome!

Thanks for the additional info....but...
But, unfortunately I'm a bit more confused.
'Cuz if what you write is correct, then the photo doesn't look right....and if the photo is correct, then what you describe doesn't make sense.

Originally Posted by RBCurtis

Thanks John, for the wealth of info provided. The boat is in the Caribbean, and I won’t be back for a few weeks, but I’ll tell you what I know now and follow up later. Your reply reminded me of other devices on board that I didn’t mention previously.

The boat is a 2004 44’ cruising catamaran, originally purchased in Europe, cruised in the Med, and then sailed to the Caribbean about five years ago. No pilots as far as I know.

We have what I think is all original Raymarine nav equipment, including autopilot and analog radar, but no working chart plotter or other display. Refit planned, which is one reason I want to understand what’s there now.

Radio wise, we have the working ICM 324 VHF, and an old Shipmate handset and an Iridium sat phone that I haven’t spent any time figuring out. Wondering now if the Shipmate is also connected to the VHF mast antenna A/B switch.

As far as I know now, no AIS. I don’t know yet what the GPS antenna is connected to, or how it’s connected.

The two identical antennae on the solar arch shown in my original photo are about 10” high in total, including the whip parts, which are only about 3” in length. They look like they’ve been there awhile.

More when I’m back on the boat!

a) What you write above means that the yellow distance is 10" and the red distance is 3"???

Kinda makes no sense....so, maybe you meant the other-way-around?


b) I think "shipmate" is a Simrad product....a handset for their VHF radio, I think? Don't think it would connect to either a Raymarine VHF, nor Icom VHF....(and, btw, Raymarine VHF's are rare, especially on European boats....so, maybe you have both an Icom and Simrad VHF's?)


c) Still just guessing, but perhaps more likely to be NAVTEX receive antennas and/or old DGPS-beacon antennas?
But, without knowing what gear is on-board, or was previously on-board....without actually being there and looking at them myself....I'm just guessing.


d) I applaud you for wishing to understand what is there....but, you kinda need to look / investigate / read / test / etc., 'cuz looking at one pic, all we can do here is guess.
Although, if you're gonna' do a electronics refit, you're gonna' rip this all (including most of the electronics wiring) out anyway...so, probably not necessary to know all of it.



Good luck, fair winds, and 73,
John

[Brian.D]

If we are going to guess at the length of the antenna, then really the only "known" dimensions will be the solar panel. Solar panels come in known LxW. With that in mind, the short edge of a panel seems longer than the total length of the antenna and base. If we were to assume (since I don't know the panel size) 36" short edge of panel, then we can assume length of antenna to be around 24" or so.

JMHO

[RBCurtis]

Sorry, I was a bit careless with the antenna dimensions ... shoulda looked again at the photo (I'm not at the boat).

Total height is probably closer to the 24" as Brian.D estimated, maybe a bit less. The base is probably 8" to 10" high, and the whip part probably ~ 12" high.

[RBCurtis]

Originally Posted by ka4wja

b) I think "shipmate" is a Simrad product....a handset for their VHF radio, I think? Don't think it would connect to either a Raymarine VHF, nor Icom VHF....(and, btw, Raymarine VHF's are rare, especially on European boats....so, maybe you have both an Icom and Simrad VHF's?)

You are correct about the Shipmate ... Simrad VHF handset. No Raymarine VHF. So yes, two VHF units, ICOM and Simrad). A/B antenna switch ... guessing shared between these two radios. Backup, I guess?

Thanks to all for the help. Probably not much else to say until I can investigate more on-board. I'm not very knowledgeable, I didn't want to rip out stuff and then find out later that I should have kept it!

[Redline452]

My vote (I.e. how I would have wired it) would be one radio (probably the Simrad handset) on one arch antenna, the other radio to the A/B switch selecting between the masthead antenna or the other arch antenna.
The former for short-range crossing/harbour communications, the other for longer range, weather, etc with the arch option in case of dismantling or traveling with the mast unsteppped (locks, bridges etc).

[Icarus]

Just have a look where it is plugged in to?
I would guess it's an UHF antenna with a booster build in.

[MJH]

Originally Posted by RBCurtis

New (to me) boat, first time boat owner.

I have two of these antennae, one on each side of the solar arch.

Can anyone tell me what they are for? I have a VHF antenna on the mast, and a GPS antenna on the rail ...

Thanks!

HINT...Follow the cables to learn what they are attached to! There is a possibility that they might not be attached to anything, a common happening when folks remove old gear.

[NNBill]

Just my two cents worth of thoughts. Since you are planning on upgrading just about everything electronics wise, save yourself a lot of headaches down the road. Don't worry about what is what, and what goes where with this installation. Equipment these days all "talk" to each other via an NMEA200 network, so any Raymarine SeaTalk network at this point is very obsolete.
These days Raymarine uses a slightly proprietary SeaTalk NG network. Data is generally NMEA200 compliant, but with proprietary hardware. Just about everyone else uses Micro-C connectors. So, bottom line, your boat will sit at least an inch higher in the water after removing miles of old obsolete wiring, cables, and hardware. You will also be confident there are no questionable splices anywhere in the new system, and that nothing will be suffering from the "green crusties"

[Djarraluda]

One other possibility to ad to the Navtex, DGPS option is a TV antenna, but I am not familiar with N hemisphere systems nowadays.
Roger