FCV800 and B275LHW Chirp frequency preset

[Natebrej]

Been running this combo a while now and I love it, The HW is perfect for Pelagic fishing marking Bait/Billfish at trolling speed and in shallower water for finding fish ground, the CHIRP images are crisp and I cannot fault it.
The L frequency is also on point in all depths I’ve tested it to so far.
My question relates to the CHIRP preset function and more deep drop fishing, If I fix my centre frequency to say 65khz will this narrow my cone width and give me better pin point accuracy when in deep water, or switch to CW?
So in 300m instead of a 130m cone it will come down to 80m?
I have been targeting Ruby Snapper/Blue Eye/Swordfish in 250 to 600m is there a specific frequency that would show them up the best?
I’ve found im having to play with my TVG, Gain, Gain int calibration, clutter/color erase a lot at every spot i go to and when on the move..
I also have a TM260 on my transom as well that I can utilise..

Some Screenshots attached

 

[Natebrej]

Some HW screen shots as well

 

[TheReaper]

@Deep Blue

 

[Deep Blue]

Natebrej,

Here are the specifications for the B275LHW:

Power Rating: 1 kW

High Frequency: 150-250 kHz - Constant Beamwidth: 25°
Max Depth High wide frequency- 152 m (500')

Low Frequency: 42-65 kHz - Low Frequency Beamwidth: 25°-16°
Max Depth: Low frequency- 914 m (3000')

Adjusting the B275LHW's frequency on the low side alters the transducer’s beamwidth by approximately 2.5° degrees per each 1kHz.

Higher frequencies will enhance the resolution for fish target separation buy using a narrower beamwidth, however it will have reduced depth capability. Conversely, lower frequencies offer a wider beamwidth and will provide greater depth performance but will have significantly lower resolution for distinguishing fish targets.

I would like to tell you to just use this particular setting for this fishery, or that particular setting for that fishery. But its all depending on the changing water conditions like temperature, water depth, and the sea conditions. I like using CHIRP frequencies for the pelagic fisheries, and a fixed frequency for the demersal fishing.

- Deep Blue

 

[Natebrej]

Natebrej,

Here are the specifications for the B275LHW:

Power Rating: 1 kW

High Frequency: 150-250 kHz - Constant Beamwidth: 25°
Max Depth High wide frequency- 152 m (500')

Low Frequency: 42-65 kHz - Low Frequency Beamwidth: 25°-16°
Max Depth: Low frequency- 914 m (3000')

Adjusting the B275LHW's frequency on the low side alters the transducer’s beamwidth by approximately 2.5° degrees per each 1kHz.

Higher frequencies will enhance the resolution for fish target separation buy using a narrower beamwidth, however it will have reduced depth capability. Conversely, lower frequencies offer a wider beamwidth and will provide greater depth performance but will have significantly lower resolution for distinguishing fish targets.

I would like to tell you to just use this particular setting for this fishery, or that particular setting for that fishery. But its all depending on the changing water conditions like temperature, water depth, and the sea conditions. I like using CHIRP frequencies for the pelagic fisheries, and a fixed frequency for the demersal fishing.

- Deep Blue

Thanks for the response Deep Blue
That’s my thoughts exactly, CHIRP for Pelagics and fixed for Demersal, If I have a preset saved that runs the L on fixed CW at say 65khz in your opinion would this give me better target imaging in 300m? And of course I’m always adjusting the other settings to suit.
I’m starting to think I’m asking too much of a 1kw transducer and should start thinking about upsizing to a larger unit

 

[Deep Blue]

Natebrej,

While I like the FCV-800 and the B275LHW is does have some limitations when it comes to depth.

So, if you plan on going targeting deeper demersal fisheries that may be off the bottom and are deeper than 900 meters (3000 ft), then you'll need a higher power fish finder with a transducer (2-3 kW) that features a lower frequency range around: 38kHz or even 28kHz.

- Deep Blue