External alarm for GP33

lshick

Member
The wiring diagrams in the manual for the GP33 indicate the ability to connect an external (user-supplied) buzzer/alarm. It appears from the wiring diagram that this alarm can be triggered only by the speed-alarm event, and not by the anchor alarm event (wiring diagram pins 7-8 are labeled "speed alarm," and page 6-5 refers to a "speed-based alarm").

Is this a correct interpretation? The issue is that the GP33 is going to be mounted some distance from my berth and I'm concerned that the built-in buzzer will not be loud enough to wake me for a dragging anchor.
 
Ishick,

If you connect an external alarm to the GP33 (even know it says "speed" alarm) then whatever alarm goes off (speed, anchor, XTE, WAAS/DGPS, trip, or odometer) will then use the external buzzer rather than the internal buzzer.

So in short, if you have an external buzzer installed on the GP33, then the GP33 will use the external buzzer for all alarms.
 
Wonderful! That response prompts two further questions:

1) "...Rather than the internal buzzer." Does that mean that if I connect an external alarm it will somehow shut off the internal buzzer?

2) What are the specs for the external buzzer--max current, voltage, impedance, etc.?
 
Larry,
Just a standard 12 VDC low amp buzzer will work. as far a limitations on what buzzer you can use:
Max of 12VDC.
Max of 100 mA.
Usually just a standard 12 volt buzzer that you can get at radio shack should work.
 
Connected a small piezo buzzer to the purple and grey wires of the GP33 and attempted to trigger it with a simple speed alarm. Internal GP33 buzzer sounded but the external piezo buzzer was silent.

Any thoughts?
 
Maybe the wires are reversed? Maybe the buzzer is too big (uses more than 100ma)? Maybe the buzzer isn't fast enough to respond to quick pulses (try continuous alarm setting)?
 
Testing a current model GP33, I think what may or may not have been true in 2016 when DB Cooper posted, the External buzzer only works for the speed basis alarm. The other alarms only trigger the internal signal alarm buzzer; not external.
 
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