Transducers

[Don G]

I have been looking at some of the snapshots of both HB & Lowrance..

Question::: When is it best to use the 800khz? Deep or shallow? What degree cone is it?

I see the HB 798 does not have the 800khz option...

[blueball]

i believe i read somewhere where the 455khz is a wider beam,but with the 800khz u get alot more detail,

[Humminbird_Greg]

For the Humminbird units:
The 455kHz sonar beam is 86 degrees (@-10db).
The 800kHz sonar beam is 72 degrees (@-10db).

Since the 800kHz is a higher frequency it is capable of producing a finer detailed sonar image. However, the downside of that is that the higher frequency will not go as far in the water and so will not work out as far nor as deep as the lower 455kHz frequency will. While the 455kHz should work down to about 150 feet, the 800kHz is more for shallower water.

[wvspec]

Greg,
Thanks. The 455k and 800k are for SI? If so, then what is the distance to the side that shows good image for both. I have a 798 and 997. Thanks for the help

[Humminbird_Greg]

wvspec,
Yes those are the Si frequencies. I don’t know that we spec an outwards distance for either frequency. This would vary with the water conditions as well as the transducer mounting. I usually don’t use the 800kHz at more than about 40 – 50 feet deep on our lake here. It may work deeper but I’m not looking at Si at those depths.