FCV-1200L bottom return

[Nick]

Hello,
I would like to ask Furuno people here about one FCV1200L installation. The unit is connected with 28kHz transducer on LF port and with 50kHz transducer on HF port. The strange thing is that the 50kHz having stronger bottom return then 28? For 50kHz I'm sure that is properly installed because the transducer cable have label. 28kHz cable don't have label, but installation made by authorized Furuno dealer, so probably everything is fine with taps and setup. According to fish appearance seems that the 28kHz is wider but according to bottom 50kHz is wider, so is that normal or...? Thanks, Nick

 

[Nick]

Same parameters has been chosen for both frequencies.

 

[Nick]

Connected transducers are: (from XDUCER SETTINGS)

HF:
Frequency: 50kHz
Type: 50B-9/9B
TX power: MAX
Output power: 1kW
Supply Volts: 42V

LF:
Frequency: 28kHz
Type: 28F-18
TX power: MAX
Output power: 2kW
Supply Volts: 67V

Gain, TVG, NR, IR, Signal level, color reduction, pulse lengths, repeat frequencies...and other parameters are the same but the bottom echo from HF is stronger then from LF. I don't know why?
Thanks
Nick

 

[Snips]

Nick,
Thanks for added the model of transducers.
That explains why the fish targets are longer on the 28Khz but the bottom is thicker on the 50Khz. The reason is the beam width difference between to two transducers. The 50B-9 is 12 x 28 and the 28F-18 is 17 x 18. So the 28F-18 has a wider (17) for/aft beam than the 50B-9 (12) so you fish targets will be longer. Your bottom return is keyed to the widest beam width, it doesn't matter if it port/star or for/aft. Hope this helps.

Snips

 

[Nick]

Thank You Snips, that is explains all. I don't even think about it, and I didn't take look in transducer specifications. Thanks again!