Humminbird 798sici Losing Pixels at speed (Help Please)

[squidboy]

Hi Raiders,

I have been adjusting my transducer position and settings from time to time to ensure that at speed, being 20 to 30 knots I have pixels on the screen to show the bottom. Currently I can get some pixels using the split screen sonar on 200htz but the 83htz is terrible, I am luck to see anything on the screen. I have a Quintrex Top Ender, and I have mounted the transducer in between the ribs of the hull. The Sounder I have is a Humminbird 798cisi

I have:
1. adjusted the sensitivity
2. played with the contrast
3. restored factory settings
4. lowered the transducer
5. pointed the transducer slightly forward

I have been on the you tube channels and read the many forums. Just seeing if there is a chance someone can pick up what I am doing wrong. Mind you it has been to a dealer twice with no result which is a bit frustrating. I have spoken to the Humminbird support (very helpful) who also stated that the 83htz should show a better picture than the 200htz, I am experiencing the opposite. I am using it between 8 and 35 metres of water (shallow saltwater). Happy to give the details of the settings of the sounder. If its easier to talk over the phone, just PM me and I will send you my number.


I have attached the photos below for people to see my set up. I live in Ryde, so if anyone has a chance to see it or show what I am doing wrong on the water it would be greatly appreciated. If you cant, and can let me kow your thoughts it would be just as good. As you can imagine, I am scratching my hair off my head just typing this email.

Appreciate any help please.

Marco.

[Nolongeramember]

As far as I know 200Htz shows a much better detailed picture than 83Htz or anything lower than 200.

[Nolongeramember]

Are you getting a good picture at slow speeds?

Looking at your transducer pics I would lower the transducer another 10-20mm. You have those strakes underneath that can disrupt the picture.

[squidboy]

I am definitely getting a better reading at low speeds. I'll try another lowering to the point it rooster tails.

[Nolongeramember]

Mine has to rooster tail to work properly so don't worry about that. If it's working well at slower speeds then you will find that generally the lower you go the better the reading at speed.

[daniel944]

Both my boat and my Dad's both have SI transducers. My boat still works at 40km/h (top speed) but my Dad's boat wont work above about 10km/h. I installed both and have never been able to figure out the difference.