I just bought two of the Helix 12 SI Sonar/GPS Combo from Cabela's. I was looking at the Helix 10s but hey...couldnt pass these up.
They have two left at the Allen store for$1,499.99 ea. Just add a mega transducer and you have mega si.
https://www.cabelas.com/product/Humminbi...mp;gclsrc=aw.ds [/quote]
You might want to check the HB descriptions on their website. That unit at Cabela's appears to be the older model Helix (not G2N) and to add a SI Mega transducer you'll need the Helix 12 Mega SI. A Mega transucer will work ( i think) but you don't get the higher frequencies that make it mega imaging. [/quote]
You cannot add MEGA frequency to a unit by adding a MEGA transducer. The unit produces the frequencies NOT the transducer.
The MEGA SI transducer has a dedicated Down Imaging crystal, a first generation SI unit doesn't have a circuit for it.
You can't view CHIRP Imaging with a first generation Helix 12. It has CHIRP 2D sonar ONLY. You can't view MEGA or CHIRP Imaging from a MEGA SI model on a first generation Helix in any size.