matt_colie wrote:
Gordon wrote:
I have a SH 300i chartplotter with all the standard alarms, etc.
The audible alarm is the same beep as the keyboard input beeps so is
not loud. It is not adjustable and there is no remote alarm jacks.
So, with it mounted at the helm and you're at anchor and taking a nap
below, how do you hear the anchor drag alarm?

I thought of a baby monitor but most, if not all, require ac at the
xmitter which would be another pain.

So, any suggestions?

I'm trying to get a schematic for the alarm circuit from SH but I
doubt they will come through.
Gordon
Gordon,

If you search, you can find baby monitors that run on low voltage DC
from a wallwort and that could be replaced by a small regulator on the
ship's power. The receivers are usually battery powered.

I had the same complaint form an owner that could not hear the alarms (I
think it was a 180) while at the helm and under sail.

We could not get any service information or assistance from SH. I could
not isolate the key beeps from the alarms.

We were able to crack the box open and tap the board at the speaker - it
is a micro speaker that gets fed a square wave - so the signal was about
1v at 300hz. That was enough to drive an switching circuit that could
fire a good old Sonalert. He can hear that.

Good Luck

Matt Colie

What does the switching circuit look like? And which Sonalert?
The 180 is the same machine as the 300 so this should work.
Thanks
Gordon
BTW, the SH tech is supposed to be snail mailing me a schematic.