this season my st50 depth sounder seems to have a mind of its own. i glassed in a pipe and put glycerine in it, but all i get on the panel is 00. can anyone offer advice what to do .
I am afraid I don't know the answer to your problem but Raytheon were very helpful when I had a problem with my ST50 log. Try them on www.raymarine.com
You should be able to hear the transducer clicking when you put it up to your lug.
If it is, then the receiver may be faulty. Although not familiar with the model can you increase the 'gain' of the receiver?