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I am about to begin Phase 2 of the Alberg 30 #439 project and was wondering if I need to get a new thru-hull transducer or will the old one work?
I think this is a transducer, thought it does not look like it was installed "flat" like I have read they should be. (This is a photo from when I bought the boat, it has been repainted)
I don't have the boat nearby, but was wondering if a newish fishfinder would work with what I have, or should I get a whole new transducer?
I don't have an answer for you, but I'm also working on an Alberg 30. I don't suppose you've been detailing any of your work on a website, have you? I'd love to compare notes and see some photos of your project.
You are correct about the "flat". These devices measure the distance from the transducer to a target at 90 degrees from the flat "face". There are several different frequencies and transmission angles used. If you know exactly what the devices characteristics are, you could determine whether or not it would work with a different manufacturer's electronics. The far easier course would be to remove it and install the one that comes with new electronics. The Raymarine Series 60 is a good example. When you remove it, it would be very easy to build out a proper mounting to insure that your new transducer is pointing at the bottom rather than somewhere abeam. Another option is to plug that hole and put the device amidships, forward of the keel, where you might pick up a shoal before you hit it. Placing it up there will probably require you to fabricate a "bump" on the bottom that is flat for the transducer mount and faired into the keel so it doesn't present a lot of drag. The picture that you showed, is the place where a lot of folks mount a speed transducer (knotmeter). Perhaps what you are looking at is the blank plug that is used for a knotmeter to plug the hole while the transducer itself is pulled for cleaning or service.
So that isn't a transducer? I will be back at the marina in early May and will look at what is on the other side of that thing! I had assumed it was for a depth sounder. I have no idea what sort of electronics were with the boat originally. There's nothing in there now, not even a battery.
David -- I bought the boat last April and should be finished fixing her up by July. I have two posts here that you might want to check out. Other than not having a working engine and some minor cosmetic problems, the boat was in somewhat decent shape, so this is not really a restoration on the level of what people usually talk about on this forum.
Let me know about your Alberg. I am something of a novice, but enjoy seeing other boats. I would be particularly interested on where to stick my new aluminum fuel tank.
That definitely looks like a transducer to me. My boat came with a log and plug but that looked much different from what I see in the photo. While most transducers should be pointed straight down and not to the side as the one in the picture is, I have seen some of the new ones that are built with an angle on the head so that the transducer in the hull is straight up and down while the head that sits flush with the outside of the hull is angled to match the hull curve creating a much lower profile and reduced resistance. I think the angled head is a new thing so I wouldn't expect yours to be of that type. I bet that is a standard transducer that was installed improperly. I have learned to never trust a previous installation after having some problems with previously installed equipment on my boat. Poor workmanship is not uncommon.
I have heard of mounting the transducer as far forward as possible for collision avoidance but I personally don't think you are going to have enough added warning to justify the move. The transducer is good as a trend instrument but I don't believe you are going to see a sudden shoal quick enough to back down or otherwise maneuver the boat into the clear. I would mount it wherever you have good access and an easy wiring run to the display unit. That said, there are, I believe, some high end units that will look forward to give more advance warning of reduced bottom depths but from the sounds of it I don't think you are looking at these top end machines.
In my experience, depthsounder prices are quoted with the transducer included because they need to be matched together. You might find the current transducer compatible but you might be paying for a new one all the same.
Finally, depending on what your needs are, fishfinders are often a much cheaper alternative to a true fathometer (which I think is the more correct term than depthmeter, or maybe they are just interchangeable terms). A true fathometer gives more information on bottom type (mud/rock etc) but otherwise a much cheaper fishfinder will tell you how far away the bottom is with reasonable accuracy.
It's ideal to have the transducer facing directly downward, but it will still work the way it is--you just may not get absolute accuracy.
However, older transducers rarely work with new equipment, so you'll probably need to replace it. If you do replace it, it would be best to build a fairing that would allow the new transducer to be horizontal.
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