Helix Sonar G2 Chirp GPS 83 khz

[JohnK]

If I’m reading the info right the Helix 5 and 7 sonar G2, chirp, gps units only supply conventional sonar in the 200 and 455 khz. range with the supplied transducer. That’s like maybe 5 ft. of bottom at a 20 ft. depth on a 20 degree beam? Why can you get 83-200khz conventional sonar with si units but not di? (83 khz at 60 degrees should show 20 ft. of bottom at 20 ft.) I’m unable to find a transducer for those units that does 83 khz.
I have a unit unopened in a box and was getting another but looking at this it may not be what I want.

 

[BluFish]

If you go to Humminbird's Website .....Humminbirddotcom.....you can find the INFO, as well as the Optional Transducers you would want. If you FB at all.....join one of the HB groups like "Humminbird Helix Tips & Tricks"....and you will fast track your Education on using your Birds....D

 

[doomtrpr_z71]

If I'm not mistaken it's because di doesn't use those frequencies. I think you can upgrade transducers to get the frequencies for 2d only.

 

[JohnK]

I looked at HB site and what I think is that if I'm standing in the bow using conventional sonar with the above units the usable portion of what I'm looking at is a half circle roughly 2 feet diameter front of the TM at 20 ft. of depth. The rest is under the TM and boat, all of DI is under the boat. If'n I had 83 khz the circle diameter would be 10 feet in front of the boat......big difference.

 

[doomtrpr_z71]

You do realize downimaging doesn't use a cone, it uses beams instead, at 455khz it has 75° of coverage. It will be a larger view than 2d.

 

[TroyBoy30]

Down and side is not a cone. It’s a slice. Only 2d is a cone. With the helix 5 and 7 you’ll want to use the transducer exchange program and get rid of the compact si transducer for the full size. You will need to call humminbird to do the exchange before you open the package.

 

[JohnK]

Thanks for the transducer tip, I'll do it.
This unit has 2d as well as di...2d only in the 200 and 455 khz which is 20/16 degree beams whereas an 2d 83 khz capable unit would have 60/20 degree beams and so be much wider at the bottom. Do people use them at the front or at the console and get a 2d only sonar/gps for the front? Then they would have the bigger cone and since all the di is under the boat when you look at it why would it matter in front?

 

[JohnK]

I bought this unit cheap from walmart back in the summer for the tm and meant to get a 7 just like it for the console. After looking at the 2d limitations it would seem like I should put this one at the console at get another 5 for the bow...one that is only 2d and gps so I would get a bigger cone and not miss the di since it's already under the boat when I see it.

I've evidently got this thread messed up and will start another that may be clearer, thanks.

 

[JohnK]

You do realize downimaging doesn't use a cone, it uses beams instead, at 455khz it has 75° of coverage. It will be a larger view than 2d.

That's right, everything shown on di is already in the rear view mirror. Great for marking way points not so much for fish right in front.

 

[TroyBoy30]

for scanning i normally run 83/200 together. on the bow vertical fishing i run 200 only

 

[JohnK]

The hb di units only have 200/455 khz 2d. Would you think getting di on the front is worth giving up the 83 khz 2d? I will already have a di/gps unit on the console for riding and marking.

 

[TroyBoy30]

i can only speak for myself but i never use 83khz on the bow. i want to know what i see on the screen is actually below me. not 20 feet to the left or right. this is my view 99% of the time on the bow

this is the other 1%

 

[JohnK]

Thanks