Topic: 999 CI HD and 800hz vs 455

[kerryd15]

Hi, I am new to the 999 this spring but have had a 798 for a few years. I have played with the 800hz and the 455 on the side imaging. I was in 10-12 foot of water and the 455 looked the same as running the 798. when I switch to 800, it really washes out on the outer edges. I was set to 75 foot to both sides. Is the 800 crystal located further forward of the 455 that i could be getting Interference with the plug? It was to the point of not making out anything to either side with the 800 and the 455 looked good on both sides. Electrical interference from the motor. I didn't try it with the trolling motor, just trolled with the big motor.

[Bob B]

Did you let the 800 Khz scroll a whole screen?  That is reported to help

There is a know problem with the 800 Khz on the 99 series units ..... Give HB customer service a call and have your serial number ready for them.

[Humminbird_Greg]

kerryd15,
Could you post a screen snapshot or two of what you are seeing?  I’m thinking that you are meaning that the 800kHz just does not cover as far out to the sides as the 455kHz Si sonar does – which is normal.  The 800kHz Si sonar beams attenuate faster than the 455kHz beams due to them being at a higher frequency.

[kerryd15]

I don't have a screen shot. imported everything to autochart and deleted the original. How wide should i be able to see in 10 foot with the 800 roughly. This was the first time out with the unit right after ice out so the deepest part of the lake i was on was about 14. I see its 455 or 800, I thought both were used. i will play with it some more thanks. Called humminbird support and my serial number was not affected. built Feb of 14.

[Humminbird_Greg]

I don’t know that there is a set distance you should be able to see out to each side with the 800kHz as this will be influenced by the water and lake bottom conditions.

[kerryd15]

Thanks greg

[kerryd15]

this is a snapshot of my 800hz. is this what it should look like? setting issue? i will post a 455 image also.

 800 snapshot.doc (1111 kB - downloaded 320 times.)

[kerryd15]

this is a 455 image.

[Humminbird_Greg]

I don’t use HummViewer, so I couldn't tell you if those look right or not.  Can you post screen snapshots from your 999 unit instead?  Again, a lot of this will depend on the bottom conditions you are over.

[rnvinc]

Your Humviewer images are normal for that bottom type that you happened to be recording ...(800kHz is usually darker than 455kHz because of frequency attenuation of the sound pulse) ...

Right click on the SI pane in Humviewer ...

In the popup will be several tools for adjusting the images ...

Rickie

[kerryd15]

800 screen shot

[Bob B]

Sure doesn't look right to me ..... you are loosing detail at a pretty short range and there seems to be a couple different kinds of interference going on.  One causing the white dots and another the vertical lines out to the side.

[Humminbird_Greg]

I agree with Bob B on this except those are horizontal lines.
Do you see the white dots and horizontal lines when using the unit on the water?
Do you know of anyone else who is running a Humminbird Side Imaging unit (any model( that you could cross-test with?

[kerryd15]

I will try and find someone with a similar unit to test on my boat. the docks aren't even in the lakes yet. I was running the big motor during the screen shot. I have some recordings but just this screen shot. Any ideas what could be causing? The 455 looks good. I will play with the 800 when I have the trolling motor running. I should have my 798 back by the weekend also. What does a ferite ring do? would it help with the interference? Does anyone have a screenshot of the "washout issue?

[Bob B]

Well since none of that interference wasn't visible in Humviewer, I must not be present in the raw data......Not sure where that gets us though.

Greg .... Those lines are horizontal to the bottom, but vertical on the screen ....

[rnvinc]

You can play your HB recordings back on the unit and capture screenshots to the same SD Card while the recording is in Playback ...

The recording will pause while the screenshot is being written to the SD Card ...

Rickie

[Humminbird_Greg]

Ferrite rings are electrical chokes used to filter out unwanted frequencies from an electrical signal (interference).

I don’t have any screen snapshots of the 800kHz washout issue.