Depth finder

[EvinFla]

I have a Hummingbird that came with my boat. Display works but it gives incorrect depth readings. Can the transponder be replaced, or should I just replace the entire unit?<br /><br />Also, does the unit operate wholly on the single transponder for readings?

 

[whiteknight]

Re: Depth finder

cabelas has garmin 240 on sale now for 199.or garmin 250 for 239 I would use humminbird for fish cover at approx 30-100 feet

 

[18rabbit]

Re: Depth finder

Also, does the unit operate wholly on the single transponder for readings?

Airmar makes the transducer. It has a single, ceramic element that swaps functions back and forth, between transmit and receive.

 

[Troy_from _Oz]

Re: Depth finder

EvinFla - Im just wondering why your sounder is giving you incorrect depth settings?<br /><br />Is it like a constant offset or does it get worse/better with increasing depth?<br /><br />Im just trying to start with the cheapest repair option which could be that the unit doesnt have the right settings. (draft, sound velocity)<br /><br />cheers <br />Troy

 

[waterinthefuel]

Re: Depth finder

Hmm, a Humminbird not working right....I just can't figure it out! LOL

 

[Troy_from _Oz]

Re: Depth finder

The only Hummingbird sounder that I know of having problems (that I've directly known of) is a local boaty who isnt getting any signal return at all....<br /><br />How do I know this? I found his transducer on the banks of the river just recently! I might add that it was mounted to a 2 foot section of light duty timber (presumably bolted to his transom). I guess the owner didnt figure on it falling off when he hit something. <br /><br />If only i knew who he was so that i could give it back to him....

 

[18rabbit]

Re: Depth finder

...could be that the unit doesnt have the right settings. (draft, sound velocity)

The velocity of a sound wave is not affected by its attributes; frequency, amplitude, duration. The velocity is affected by the density of the material the sound wave is passing thru. Heat alters molecular density, thus the velocity of sound is affected by the temperature of the material (water).

 

[Troy_from _Oz]

Re: Depth finder

agreed rabbit. I would also think that the molecular density is affected by salinity...<br /> <br />However, my point was that if the setting within the head unit for sound velocity is 1000 m/s and the actual sound velocity is 1500 m/s then then there will be a scale issue in depth readings which might show up in readings at different depths (maybe im wrong??). Not being sure of what settings EvinFla can change in his head unit - i used the term of sound velocity as in the end this will be a function of temp and salinity.<br /><br />You can't change the physics, but changing the equations that are used to express them can cause errors.