Depth Sounder Transducers

[rondds]

i have ORIGINAL (1989) datamarine combo depthsounder/temp gauge/speed log on my boat, with a behind the dash "black box." only the sounder works, and that loses the bottom very frequently (turbulence, no reason, whenever). my chartplotter (garmin 492) can also function as a sounder and water temp gauge. i THINK i'd need the proper black box (gsd 21) and a 500W transducer.

my questions are as follows...
1. will the transducer from my old datamarine work with the new setup?
2. if not and i have to pull the old transducer out (it is a thru hull), what are the odds that the new one will be the same diameter?
3. will the wiring that currently runs from the transducer to the flybridge work, assuming i have to replace the transducer (i cant imagine how difficult it may be to run the new wiring to the bridge).

datamarine's website contains no information on such matters - it almost looks like they are getting ready to close shop (all their merchandise is on closeout at Defender). thus, i doubt they can give me any guidance. therefore, any advice/experience would be great

 

[boatmailster]

i have ORIGINAL (1989) datamarine combo depthsounder/temp gauge/speed log on my boat, with a behind the dash "black box." only the sounder works, and that loses the bottom very frequently (turbulence, no reason, whenever). my chartplotter (garmin 492) can also function as a sounder and water temp gauge. i THINK i'd need the proper black box (gsd 21) and a 500W transducer.

my questions are as follows...
1. will the transducer from my old datamarine work with the new setup?
most likely will not work with newer unit from different manufacturer
2. if not and i have to pull the old transducer out (it is a thru hull), what are the odds that the new one will be the same diameter?
like everything in life 50-50 (but you may want to use transducer glued to hull bottom)
3. will the wiring that currently runs from the transducer to the flybridge work, assuming i have to replace the transducer (i cant imagine how difficult it may be to run the new wiring to the bridge).
it is not recommended to splice transducer wires, but it will work if soldered nice and clean
you can use old wire as a pull line for new wire
datamarine's website contains no information on such matters - it almost looks like they are getting ready to close shop (all their merchandise is on closeout at Defender). thus, i doubt they can give me any guidance. therefore, any advice/experience would be great

many times there is line left inside tubes to pull new wires to flybridge

 

[CSR_Admin]

The ducer will not work with the 492. You will need to get a garmin ducer. It is likely the new ducer will fit the same hole as the old, just need to let me know which ducer you have, there is a tag at the plug end that will tell you. You will need the GSD-21 and a new ducer. Honestly I would buy a 498 and a ducer and then have 2 screens. 498's are just over $400 right now. The GSD-21 is $221. The 498 will not require a gsd-21. Pulling the new cable should be pretty easy just tape it to the old cable and pull it through.

I am going to move this post to the electronics forum.

 

[rondds]

jim
good suggestion - i didnt know the 498 had the sounder built in! if i did, i'd have gotten it! i only bought the 492 b/c i dont fish and didnt need the "fishfinder" function. if only i knew!!!! :smt013 doesnt make sense to get the 498

i was aware that i need the 21, but do you know which transducer i'd need?

 

[CSR_Admin]

Depends on what you have no if you want to fill the same hole. I would look into a B60-20 from airmar, that should fill your hole: http://www.byownerelectronics.com/store/product.php?productid=17232&cat=0&page=1

 

[rondds]

ok, now i'll show my ignorance. i was under the impression that you had to use a GARMIN transducer. guess not. also didnt realize that i'd need something to offset the deadrise. but that makes sense (inaccurate readings that get more inaccurate as depth increases). i am familiar with the term "fairing" but had no idea what it meant. i guess that fairing provided with a regular non-tilted transducer would stick out of the hull and increase drag. sheesh! i've got a lot to learn!

 

[CSR_Admin]

All Garmin ducers are made by airmar, same for Furuno and Ray.