Echomap Black line in 800kHz...?

[bassrom17]

Hi Guys!

I am a french guy so sorry for my english. I dont know if I need to make a presentation before posting or not!

I found your forum after a long research about my new echomap CHIRP 92SV! I is really helpful for me because I sent email and ask on garmin Marin Facebook some question and they just ask me to call an other service. So they dont know.

I had an elite 7 HDI before with really good down image, better for me than the downvu on my garmin. Fish just pop on the screen easily, now after maybe 20 hours of fishing I never so fish like before. I tried to ask garmin about the dedicated crystal on the down vu or not... no answer yet. But anyway it is not the reason why I am here.

On the sid vu I have a black line on the 800kHz ducer and nothing on the 455kHz. You can see it on my image (sorry it is not a good screenshot but a phone pic).

First pic on 455kHz: almost ok fish on left side, nothing on down, some stuff on 2D. I tried brightness/contrast/TVG setting and mixed them... NO fish on down...


2nd and 3rd pics: first part of the side vu is on 455 and end part is on 800kHZ, You can see that black line on the 800 Khz witch is absent on 455Khz.





I fish only freshwater and max 30 meter. So for me 800kHz is (should be) the best way.
I tried to move the ducer (up down roll on the left on the right)... nothing change but when i roll on one side (maybe i should say "tilt") the black line is stronger on one side and weaker on the other but never disappear.

so if you have any idea i would be very happy to read you!

[LWINCHESTER2]

I have an echoMAP CHIRP 93sv which internally is the same as your unit. Just different maps. I've used it with GT50, GT51, and GT52. Never seen anything like this.

Can you get some pics of the installation? Both from the back and from the side. Let's make sure there is nothing obstructing the signals.

[Larry3215]

If you mean these black lines....



garmin1.jpg

They are interference between the downview and sideview signals. They will only show up when both downview and sideview are set to the same frequency.

If you switch your downview to 455, then those lines will likely show up on the sideview when its set to 455 at the same time, but they wont be there when your on 800.

[Larry3215]

Here are some examples from my 7610 GT51.

20MAY16_1328_00.jpg

I also get them on 455 when Im running my Panoptix PS21. Its on 415 I think.

[Larry3215]

Oh, those are often called ghost lines.

[Larry3215]

By the way, your transducer does have a dedicated down element as far as we know. Also, as you have found out, Humminbird has far superior side and down imaging as far as detail, clarity and sharpness when compared to Garmins. The Garmin should have more range though. You may also find that the 2D CHIRP on the Garmin will be better than the 2D on the Humminbird if that helps.

[bassrom17]

I have an echoMAP CHIRP 93sv which internally is the same as your unit. Just different maps. I've used it with GT50, GT51, and GT52. Never seen anything like this.

Can you get some pics of the installation? Both from the back and from the side. Let's make sure there is nothing obstructing the signals.

I can't take picture right now but nothing obstruct the signal! My ducer is on a special stick and I can tilt it and move it like I want. I tried many thing. and at least I put it the deeper as possible and take the motors off the water to be sure nothing obstruct. But anyway i get the same result.


///

If you mean these black lines....

They are interference between the downview and sideview signals.

Yes I mean that black lines. I read something about the interference on thread here. And I am 99% sure I tried to switch 455kHz DV and 800 kHz Sv and get the same result. Next time I am able to make a test on water (maybe in 1 or 2 week :( ) I will try and show you.


///

By the way, your transducer does have a dedicated down element as far as we know. Also, as you have found out, Humminbird has far superior side and down imaging as far as detail, clarity and sharpness when compared to Garmins. The Garmin should have more range though. You may also find that the 2D CHIRP on the Garmin will be better than the 2D on the Humminbird if that helps.

If it is a ghost line it's really annoying!

Yes i ask garmin about dedicated transducer for downvu and YES it is a separate one. I also ask for that line yesterday but for the moment no answer. I'll keep you informed.

I agree with you for the lack of detail. I never use HB but lowrance and the downscale was far far better! and it was a 2012 unit (I think). Elite 7 hdi.
Never use SI or DI on HB so no idea. but the screenshot I saw on the net are also better on HB.
2D on echomap are good, very good the best I have seen for now. But close to my Elite 7 where I was mainly using the Downscan, because it was really easy to find fish.

I don't need an big range for side, I am fishing lake and river and I really need detail and separation of target.
your answer let me think about return it. Going back on Lowrance maybe, an elite 9 ti totalscan could be a good option or helix 9 SI/DI, but paying for autochart when its free on lowrance or garmin let me think to not buy HB.

Maybe in europe we are not concern by navico patent on Downscan and HB get also a dedicated down ducer.

///


thanks guy for your help ;)

[bassrom17]

Hi everybody,

to close that subject I will explain you the end.

Garmin asked me to sent us the product because for them there was a default. I needed to get my product soon for a trip so I returned it to the store, and bought a Simard Go7 Xse, plus an iPad air 2 both in sale for the same price of my 92SV.

Just installed and not tested.

Thanks for your help. And yes for Garmin it was a "non conventional issue" they told me it was the first time for them.

[Larry3215]

Hi everybody,

to close that subject I will explain you the end.

Garmin asked me to sent us the product because for them there was a default. I needed to get my product soon for a trip so I returned it to the store, and bought a Simard Go7 Xse, plus an iPad air 2 both in sale for the same price of my 92SV.

Just installed and not tested.

Thanks for your help. And yes for Garmin it was a "non conventional issue" they told me it was the first time for them.

They actually said they had never seen that?

Wow. There are a bunch of us who need to get our units replaced then. Me for sure!

[vik]

...so I returned it to the store, and bought a Simard Go7 Xse,

Now you will get the black lines at both 455 and 800kHz. Just have a look at SIMRAD & Lowrance screen shots at GOOGLE or in YOUTUBE. GT52 has them at 800kHz only. GT52 also has a pure dedicated DI, Simrad not:

[TeeDee]

Here are some examples from my 7610 GT51.



I also get them on 455 when Im running my Panoptix PS21. Its on 415 I think.

This is what I see on my 93sv chirp when I am on 455 dv and 800sv. When I run both on 455 I never see it. I have not tried 800 on both.

[TeeDee]

I did not mention my 93 sv is with GT52HW

[afbr]

I can't change frequencies between side view and down view on mine. If i change it on one it automatically changes it to the same on the other. Am i missing something? Mine is a 73SV.

[Larry3215]

This is what I see on my 93sv chirp when I am on 455 dv and 800sv. When I run both on 455 I never see it. I have not tried 800 on both.

Interesting. You're another exception to the "rule".

These ghost lines and waffle lines show up an all brands and at all frequencies. I get them at 260 and 455 and Ive seen them on Humminbirds at frequencies up to 1200.

The most commonly posted reason is interference caused by running the SI and DI on the same frequency - but - I have seen a lot of screen shots that done follow that rule.

Obviously Garmin techs dont look at screen shots or spend time out on the water playing with the sonar!

[Larry3215]

I can't change frequencies between side view and down view on mine. If i change it on one it automatically changes it to the same on the other. Am i missing something? Mine is a 73SV.

Some models will allow you to run on different frequencies and some dont. My 7610 lets me run on different frequencies.

[vik]

"When I run both on 455 I never see it. "

Interesting. You're another exception to the "rule".

There is no any exception - DI beam at any frequency do not effect on SI big dark lines which are at 800kHz on GT52, and at 455 & 800kHz on Lowrance and Simrad units. We discussed this before in neighbor thread:
http://www.bbcboards.net/showthread....=1#post8518354

[Larry3215]

There is no any exception - DI beam at any frequency do not effect on SI big dark lines which are at 800kHz on GT52, and at 455 & 800kHz on Lowrance and Simrad units. We discussed this before in neighbor thread:
http://www.bbcboards.net/showthread....=1#post8518354

(sigh) Yes, we did discuss this. and you were wrong then too. They occur on all brands, on all frequencies - sometimes, but not always. There is no absolute rule that is always followed.

[vik]

Yes, we did discuss this. and you were wrong then too. They occur on all brands, on all frequencies - sometimes, but not always. There is no absolute rule that is always followed.

I do not think that I was wrong claiming that DI beam do not effect on SI big dark lines. Then, yes, there is no absolute rule, but Lowrance & Simrad have them at about 95% of scanning time (screen shots), and GT52, CV52 & Hbird at about 5% at 455kHz.