Thanks, Lawrence, for the input. That is so weird regarding "blowing out" periodically. It seems like a fault of the system design (I'm an EE by training and an embedded firmware developer by vocation). I wonder if it could be an energy coupling problem where the system design assumes a certain amount of absorption via the hull/water interface. If the absorption is not there, energy is absorbed by the electronics in the transducer, thereby causing failure. My transducer appeared to be held in place with a big RTV blob, and was popped out of the blob when I looked under the v-berth. The installation video says to only use slow-cure 2-part epoxy. Regards, Rob On Fri, Jun 19, 2020 at 5:06 PM Lawrence Winiarski via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
I bought one of those depth finders and tried a lot of different mounts. It "kinda" worked at first and then Itried various ways to put it in (silly putty,wax,and eventually epoxy) it worked most of the time then1/2 the time then pretty much not at all over 3 years.
I was determined to figure it out and brought out an oscilloscope and researched these things. Kind of interestingactually. the "transducer" is an oscillator that has a natural period of oscillation at 200khz and the devicesends it a signal that is about 150 volts peak/peak for about 100 oscillations and then uses the same wires tolook for an echo that is just a few millvolts but at roughly the same freq. ( That actually makes it challenging froma probe problem to look at the same signal with 4-5 orders of magnitude of variation)
What happens (or I should say happened to me) is that the transducer basically blew it self out and couldn't receive the sensitiveecho. So I would NOT recommend gluing the thing in.
I found a bunch on ebay for $10 and took a risk buying them. They worked fine and I put in an RCA jack so that I could easily replace them. It seems to work pretty good just in a pool of water (held down with a spring) on the hull. Works pretty good now on the first replacement. My advice...Do NOT glue them in. They seem to have a limited life and you will probably need to replace them.
On Friday, June 19, 2020, 1:47:50 PM PDT, Rob Bultman < rob.bultman@gmail.com> wrote:
My 1977 M17 has a HawkEye depth finder installed by a previous owner. I'm not sure what exact model is installed, but it appears to be similar to the DepthTrax 2B currently shown on their website (
https://hawkeyeelectronics.com/collections/sailing/products/depthtrax-2b-boa... ). The transducer is "glued" to the hull in the v-berth area. I finally got the boat out this weekend for my initial shake-down sail but the depth finder just showed 0 depth. The previous owner did not mention any issues with it.
The info on that page states: Glue-In Installation is for NON-CORED hulls or aluminum hulls thinner than 1/8” ONLY. Glue-in mounting of the transducer is NOT suitable for all vessels.
Does the M17 have a cored hull or should this finder just work?
Thanks, Rob