Topic: Transducer interference (2x HDSIs via AS SI LR Y cable + Raymarine Dragonfly)

[CHOOhonets]

Hello,
Could you please give your thoughts on whether I am going to face interference with the set-up on the picture enclosed.
I have 2x HDSIs connected with AS SI LR Y cable at the same places both sides of the motor plus I am planning to place standard Raymarine Dragonfly transducer on the spot pointed with red color on the picture.
Do you think this set-up will work fine or not?

PS Raymarine Dragonfly is 2D/DI only unit.

Thanks a lot in advance!

[Humminbird_Greg]

That would depend on how wide the DI beam of the Dragonfly is and what frequency they use for their sonars.

[CHOOhonets]

Greg, Dragonfly's DI element produces a 60° side-to-side and 1.4° fore to aft beam working at 350 kHz. The second element provides a conical shaped 25° beam working at 200 kHz.
What do you think?

[Humminbird_Greg]

same 200kHz sonar frequency that we use, so yes there is a good chance that there will be 2D sonar interference.  Try turning on and up the Noise Filter in your Humminbird unit if this happens.

[CHOOhonets]

And If I use my Humminbird exclusively for SI at 455/800 KHz and Dragonfly at its 200/350 KHz for 2D/DI at the same moment - should it be OK?

[Humminbird_Greg]

Your Humminbird unit will still be transmitting and receiving at the 200kHz 2D sonar frequency.  It needs the water depth information for the Si sonar.

[CHOOhonets]

Greg, maybe it is possible to use 83 kHz 2D sonar frequency for SI water depth information?

[Rotus623]

CHOO, I was thinking of a similar ordeal for my boat. I want a little crisper images with my DI. I was thinking the Lowrance Elite 4 or Elite 5 DSI. These units only have 455/800khz and chart capabilities. There is no 200/83hz beam. My thinking was I could use the Elite DSI on the charts when running, that way I can have the whole Bird screen for 2d sonar, and when I am scanning, I can set the Elite to 800Khz and the Bird to 455 and 200khz. That way there is no interference, a stand alone chart during runs, and a dedicated DI piezo.

Not sure I want to go this route, as some tweaking has allowed me to get way better DI images out of the Bird.

[CHOOhonets]

Rotus, tell us about your tweaking to det a better DI out of Humminbird

[Rotus623]

Not sure what the rolleyes is for....... Anyways I found that setting the DI beam to wide, with the color being blue or gray, sensitivity up and contrast down helped a lot. The thing that I do not like is that I really have to change colors and fool with DI enhance and the settings are different for each of the recordings that I made in different depths and different bodies of water. It seems like the SI is much easier to optimize.

That being said, is your goal to achieve better DI with this setup? I just found out, thanks to Rickie, that we can run the DI transducer with a transducer switch for super crisp DI images. Humminbird okayed it, where in the past it was kind of a do at your own risk ordeal. Flick the switch back and forth for DI and SI. May be something to look into......

[rnvinc]

Greg, maybe it is possible to use 83 kHz 2D sonar frequency for SI water depth information?

Greg is teaching soldering classes this week so it may be a few days before he can check in...

No, it is not possible to change the frequency from the 200kHz that the unit uses for depth...

Even when setting the "Beam Select" setting to 83kHz only...the unit still transmits the 200kHz frequency for depth...

Rickie

[Humminbird_Greg]

Rickie is correct.  It is impossible to do with the current design of the units.  The 83kHz would make for a poor sonar in shallow water anyways.