Mega y cable

[Tundra1]

My connected helix’s are not reading depth or bottom in 4’ or less. Also the shoot through 2d won’t read on plane unless I wait for the units to get a reading. I disconnected the y and ran directly into the main unit and it read fine in shallow water. How do I know if I have a bad y cable or a bad high speed ducer?

[Wayne P.]

Testing on the water, you connect only the shoot thru to the display, then connect only the SI transducer to the display. Then you add the Y cable with both transducers connected to the display.

[Tundra1]

I read your instructions wrong and I disconnected the y cable completely. Plugged the mega si directly into the main unit, plugged the 2d into the helix 7 next to it and selected 83/200 and the 7 wouldn’t read anything. The main graph works great without the y cable. I reconnected both to y cable and they still don’t work in shallow, but over 4’ works good. I assume the 2d is faulty but that probably doesn’t rule out the y cable since i didn’t do it how you said. If I were to buy another shoot thru, which one do you recommend for 2 helix chirp g2ns?

[Wayne P.]

I read your instructions wrong and I disconnected the y cable completely. Plugged the mega si directly into the main unit, plugged the 2d into the helix 7 next to it and selected 83/200 and the 7 wouldn’t read anything. The main graph works great without the y cable. I reconnected both to y cable and they still don’t work in shallow, but over 4’ works good. I assume the 2d is faulty but that probably doesn’t rule out the y cable since i didn’t do it how you said. If I were to buy another shoot thru, which one do you recommend for 2 helix chirp g2ns?

Exactly what units do you have? The whole model names of each.
MEGA SI and Helix 7 means nothing to figure out what units you have and what transducers are compatible.
Which one is "main"?

[Tundra1]

Helix 9 mega si g2n gps is main w a helix 7 di gps g2n networked to it with no transducer.

[Wayne P.]

Helix 9 CHIRP mega si g2n gps is main w a helix 7 CHIRP di gps g2n networked to it with no transducer.

You still did not state the whole names, but I can figure that out. Both have CHIRP in their model names

The Helix 9 uses 83/200 kHz for 2D sonar. The proper shoot-thru transducer is the XP 9 20.

The Helix 7 uses 200/455 kHz for 2D sonar by default. Your setup should be an Ethernet cable connected between them and Sonar turned off with the Helix 7.
If you want to test the shoot-thru with the Helix 7, you have to change the Connected Transducer setting to HB 83/200 kHz.

You still have to do the Y cable test with the Helix 9 to see if the Y cable is faulty.

[Tundra1]

Sorry forgot the chirp. Yes, I did have sonar off and selected 83/200 when I ran the 2d into the 7. It wouldn’t read depth or show a sonar. I won’t be able to get on the water again til next weekend though to check y cable. I will report back then. Thanks

[Tundra1]

When I plug the 2d directly into main unit helix 9 without y cable, sonar doesn’t work. Sonar didn’t even show up in settings. Sonar does work when the mega ducer is plugged into the 9. So I take it the shoot through is faulty? You said the proper shoot through is the xp 9 20, but isn’t there a chirp model that is better?

[Wayne P.]

When I plug the 2d directly into main unit helix 9 without y cable, sonar doesn’t work. Sonar didn’t even show up in settings. Sonar does work when the mega ducer is plugged into the 9. So I take it the shoot through is faulty? You said the proper shoot through is the xp 9 20, but isn’t there a chirp model that is better?

There is a Low-Q CHIRP rated transducer that is standard for the G3/G3N models and can be used with G2N models but not G2N SI units. It is HW (High Wide 140-240 kHz). If you want to use that, you would loose SI and would have to make it a CHIRP (sonar) or a DI unit. A software update made your SI unit compatible with the Minnkota MDI transducer, it doesn't do Side Imaging.

Guessing by your testing, you either have a faulty shoot-thru installation or faulty transducer.

[Tundra1]

The installation should be good since it’s been there since I bought the boat another 7 yrs ago. It worked fine with the 898 that was on the boat. I will buy a XP 9 20 and try that. Thanks

[Tundra1]

Installed the new ducer and it works good. Thanks