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Simrad EVO 3 High Chirp to 250 kHz?

Old 12-05-2016, 10:21 PM
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Default Simrad EVO 3 High Chirp to 250 kHz?

Thinking about upgrading from HDS to EVO 3. I currently have a sonarhub and HDS 12 gen 2 with a B175 HW. I'm wondering what kind of improvements could be expected with the B175HW since the EVO3 is supposedly rated at 1k watts and high chirp to 250kHz vs 210kHz of the sonarhub?
Old 12-05-2016, 11:09 PM
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Yes, Evo3 has 1kW transmit power and will CHIRP will have max 250 kHz frequency when CHIRPing. I don't expect a very significant difference in performance.
Old 12-07-2016, 10:36 PM
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Default 210-250 khz chirp

abbor,

How much better will the performance of the b175hw be chirping with the extra bandwidth of 210-250khz since I'm currently chirping 150-210khz?
Old 12-08-2016, 12:36 AM
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Not much.
Old 12-08-2016, 06:37 AM
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Originally Posted by FishAddict12 View Post
Thinking about upgrading from HDS to EVO 3. I currently have a sonarhub and HDS 12 gen 2 with a B175 HW. I'm wondering what kind of improvements could be expected with the B175HW since the EVO3 is supposedly rated at 1k watts and high chirp to 250kHz vs 210kHz of the sonarhub?


This remains to be seen.
Old 12-08-2016, 07:55 AM
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Brian, things like this can be calculated, it's not nescessary to wait and test. The problem here is that the full resolution with 100 kHz CHIRP bandwidth will only be usable when a 20' depth range, or less, is displayed for a 800 points (vertically) screen. If the depth range displayed is larger than 20' the screen resolution will limit the resolution shown, not the sonar part. With 60 kHz CHIRP bandwidth the vertical screen resolution will be limiting if 32' or more is shown on a 800 point (vertically) screen. Zooming can of course be used, but the same limitations apply for the range displayed.

I suspect the difference actually will be even less. Because when looking at the B175H-W Figure of Merit, it's questionable if the bandwidth should be counted to 210 or 250 kHz. The -3dB point defines the bandwidth, and as we can see below it drops about 2.5-3 dB around 210 kHz.

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Old 12-08-2016, 08:01 AM
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I was referring to the 1kw, the powers that be in the States have said not 1kw.
Old 12-08-2016, 08:05 AM
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The power depends on transducer impedance. It will be 1kW for some transducers for Evo3, but even Evo2 is transmitting at 1 kW with some transducers.

From the Navico NSS Evo3 product brief: (which someone found at an Russian site and linked to at a Norwegian forum)

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Last edited by abbor; 12-08-2016 at 08:16 AM.

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