Thread: Hb 798 side imaging

Kennedy, Thanks for the advice, I might have to take u up on the offer sometime but it wouldn't be for a few weeks cause of work and then I am off to Grenada in two weeks.... We will see what happens

So when I try to go to my 455 kHz setting all that shows up in the beam select column is 200/83, 200, and 83khz settings.... When I go to transducer select and select quad beam(. I normally have it in compact sidescan). It doesn't allow me to view the side imaging screen but it brings up the 455khz sensitivity setting in my sonar choices... I'm stumped on this because I am using a xtm 9 hdsi 180 t transducer and it even says on the box that it allows for 200/83/455/800khz. What am I doing wrong?

The 798 does not have the internal circuitry to read the SI data for the 800kHz sonar beam so there is probably not a setting in the 798 menu to even select 455kHz...

When the xducer select is put to "Quadrabeam" the unit thinks you have a quadrabeam xducer attached so it looks for 455kHz oval shaped sonar beams in this depiction (even tho the "quadrabeam 455kHz oval shaped sonar beam" and a SI 455kHz fan shaped sonar beam are 2 completely different technologies)...

Basically this means 2 different sonar beams can have the same frequency (455) but still be 2 different technologies when it comes to what the processor needs to display data from that xducer crystal (or crystals)..

The 455kHz SI sonar beam is not the same as the Quadrabeam 455kHz sonar beam...





Clear as mud?

Rickie

So I'd need to keep it set at compact sidesan and 200/83khz setting?

The first section in this depiction is the SI 455kHz sonar beam and you can see how its shape differs from the Quadrabeam 455kHz sonar beam in the previous post...



Rickie

I have seen that diagram before... But my understanding. Is now that I only have 3 choices of sonar type to choose from... Is that normal for my unit and what would be the best one

Originally Posted by bowhunter1

So I'd need to keep it set at compact sidesan and 200/83khz setting?

The 200/83 2d sonar beam setting is a "blend" of the 200kHz 20degree cone shaped sonar beam AND the 83kHz 60degree cone shaped sonar beam...

This will give the best results in your 2d sonar views...

Because the 798 cannot read the 800kHz SI data from the xducer.. When the unit is showing any SI view- it is the 455kHz SI fan shaped sonar beam....

Rickie

The only instance I would ever select 200 OR 83 is if I wanted to pinpoint a piece of structure to be in the 200kHz 20 degree cone ... If the setting is at 200 and a brushpile shows on the screen.. You can be certain that brushpile in nearly "directly" under the xducer..:

A 20 degree cone is a very small cone...(something like 1/3 of your depth)..

Rickie