Re: Humminbird transducer test
Ok, I did what I said, beins I'm suffering from cabin fever and we had another 3" today (about 20" now for the month). My cows have started growing webbed feet....naw, not quite, but anything can happen. Grin
But if you are a "Coonass"(distant transplant from Nova Scotia to Southern Louisiana) and like crawfish, you won't believe the size of these suckers in the pasture......you'd think they were Maine (not Florida) lobsters....big pincers. LMAO. So I ask my Coonass wife if she wants to boil up a pot to go with some Coors and she said no.............................humph,can't win em all I guess. Sigh.
For the record, the TM is a MG Mod 767 67# 12/24 Brute. So it can make some racket if it wants. My transducer is strapped directly to the bottom of it (the steel motor housing) with a SS strap.
The wiring for the TM is 3 wire (due to the dual voltage) and goes directly to the "TM batteries" via a pair of 40A inline fuses, from the bow to the transom (area) of the boat; about a distance of 16'.
The power for the DF is a separate "twisted pair" which goes back to the "engine run" battery via a 3A fuse. The engine run /TM batteries are isolated from each other so there is no feedthru or noisy ground loops.
Additionally, the wiring is not routed together (in a bundle) so there isn't a mechanism there for "magnetic field" interference in the wiring. Therefore I seriously doubt that is your problem if wired like mine.
I have an old transducer from OEM Lowrance DF (the one installed on the boat when built) which I just secured and left in place....astetics are not important to me on this boat. I also have the transducer for the new Eagle (which is now a Lowr. subsidiary, nothing to do with Humminbird but transducers ought to be a common element regardless).
Since I am single freq (on both units), I only have 2 wires to each transducer. I went to the 20 Meg scale on my ohmmeter and it was open ckt which is what I would expect from a properly functioning Piezo.
Since you mentioned that you have a 50/200kHz unit, I feel that you have two input circuits to deal with hence a common wire (we can call it ground which is probably what it is, to the two circuits) and a separate signal wire for each of the two frequencies. I have no idea as to the input circuitry of your Hummer, but since "common sense isn't very common"....BruceB Quote, my common sense tells me that the 50 and 200k signals enter through different receiver tuned inputs requiring two separate inputs; but maybe not if the bandwidth is wide enough; but that doesn't make (common) sense for the wiring you described.
I think that any interconnection that you recorded (resistance between wires) is damage to the unit caused by the influx of water and I would suspect that your transducer is not adequately functional. But as I said I am not there, have no idea as to what the circumstances are nor do I have a schematic for the thing. Just educated speculation and a little "common sense"....just gotta keep dinging this common sense thing from my good buddy BruceB. Grin
So, I'd throw the Hummer in the trash and invest $99 in a Cuda and forget the interference and probably get a much better display that you can easily read in the daylight, which is what I couldn't do with my last Hummingbird (course it was '89 vintage) and for the record, I used to work with the guys that went to Eufala, Al. worked with Tom Mann, and developed the Humminbird back in the '80's.
Have a happy Memorial day. Around here it sucks if you had the misfortune to want to go to the lake and do some fishing and camping. BTDT many times, but no more.
Mark
