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Replace Your Depth Sounder Without Replacing Your Transducer

Replace Your Depth Sounder Without Replacing Your Transducer



Many customers ask if they can use one of our new Signet depth sounders with their old transducer so they can avoid hauling the boat.





The answer is a qualified yes!

Different transducers operate at different frequencies. The design of the Signet depth sounders allow the instrument to be tuned to various transducer frequencies. Catalina Direct can have the factory technicians tune your new instrument to operate with any transducer between 150 kHz to 299 kHz. If you can locate the owner's manual for your existing instrument, it will likely tell you the frequency of your transducer. 

 There are a couple of caveats:

If that happens, Signet will tune the instrument back to the frequency that your new transducer requires. There is no extra charge for this service, but you will suffer some additional shipping costs to get the instrument to the factory and back again.


  1. The transducer cable is assumed to be 35' in length. The instrument is measuring a timed pulse being sent through the transducer cable. If a previous owner trimmed the length of the cable, the timing of the pulse has shifted and the depth reading will be inaccurate.

  2. The life expectancy of a transducer is about 15 years. If your transducer is of that vintage, it may be on its last leg. You may receive the new instrument tuned to the old transducer and find that the transducer no longer works. 


If you already have a Signet brand depth sounder:

If your boat is in the water and you wish to replace the instrument head, it is possible to re-use your existing transducer.  

There are a couple of things we need to know:

  1. The frequency of your old transducer. The original Signet instruments were 160 kHz, newer are 200 kHz. If you don't know the frequency of your old transducer and the instrument still has enough life in it, our technicians will test it. Send us the instrument head and we will determine which frequency your system is. If old enough to be 160 kHz we will supply your new instrument tuned to 160 kHz. If you install the instrument and two years later the old transducer fails, we will re-tune your instrument to 200 kHz again with no service charge. Note that sometimes the frequency is printed on the cable jacket, near the instrument head, though not always.
  2. The style of plug your current system is using. See the pictures below to help you identify the style of plug you require. 







The style shown to the left is an RCA style plug, very much like what you'd plug into on the back of a tv or stereo.






At right is the plug style called Conxall. Notice the rounded edge of the female half (the one on the right) as well as the pin configuration. Strain relief is provided by the plastic nut surrounding the wire where it enters the body of the plug.





At left is the amp style plug. Notice that the center of the female half (on the right) has a sharper edge to it than the conxall style plug above. The configuration of the pins is also different and it has two phillips head screws securing the strain relief clamp.