Keith Hannah posted a discussion

I have the above and sometimes I go out and it reads in 1800' no problem but that's rare.  Lately I have to be at a dead stop to read 70' and even that's not reliable. Just comes and goes and hardly shows fish.I read the suggestions and checked the followingboat Bottom is cleantransducer cable to DSM is clean and appears undamaged.tried of course low and frequency.r199 is selected in DSM settingsI saw that propylene glycol is a recommended fluid but that seems off the market now, I went to 2 full autoparts places and not a single one carries propylene.. they have a new pink stuff but it's not propylene. I pulled the transducer today and it's in oil instead. It's been in there for years(I got the boat 2 yrs ago with DSM 25 and older display).   I've installed transducers in mineral oil before without issue so I hope this is okay.. again it works well sometimes.System is in a worldcat 33 to the section is flat and has no thru hulls in front of it.When it works well I can see bottom in 1500' at a few knots speed.It always pings when it's on, you can hear it back at the back.Only thing I imagine was the tank seemed to be about 1/2 full which doesn't seem like it would matter so I topped it off with more oil.any other ideas?See More