Topic: GPS antennas - confusion reigns

[Spnb8]

The features detailed for both the 998c SI and 798c SI state that the units come standard with a 50 channel GPS receiver. I haven't found what model number GPS is included with each unit. The specification pages in the 2010 catalog indicate that a GPS receiver comes with each unit and then under 'Optional Add-Ons' it shows 'GPS Receiver'. In running a Google search I come up with an AS GR16 GPS Receiver and an AS GR50 50 Channel GPS/WAAS receiver.

My question is: which external GPS receiver comes comes standard with each of these units? What is the 'Optional Add-on' receiver? Is there a benefit to purchasing one of these two receivers although I would guess the AS GR16 is only a 16 channel unit and inferior to the other - to unclude the alleged 50 channel receiver listed as standard.

[sonar2000]

Well now.   good question.

There are any where from 24 to 30 satelites in orbit.
Each satelite has about a 12 hour viewing position.
Exactly just how many are available to you at a given time probably can be found on a google search.
One thing you can do is have your unit show you the received signals and their position relative to you and the horizon.

While 50 is a good number that could be expansion and WAAS capabilities for a precise location.

If you want a good idea of satelites just do the google.  lots of info there. 

Chuck

[Spnb8]

Thanks for your response. I'm fairly familiar with how GPS and WAAS functions.
My question was: which GPS receiver comes standard with each of these units. Do they include one of the two models I found? If not, what is the purpose/advantage of buying one of them?

[stillbear]

Yes from what I understand the units come with 50 channel reciever .  According to Gregg
about three years now.     Gary

[matt888]

Let me help clarify:

I had a 797c si that had an EXTERNAL gps receiver or "puck."
I sold that boat.

Bought a new boat and bought the 798c si.  It has an INTERNAL receiver.  I'm NOT happy about that, but will see how it performs when flush mounted in my console shortly.  I feel as though Humminbird got CHEAP on us...

They now say you can upgrade to one of the receivers you mention.

[Wayne P.]

Matt888, you had your choice with the 798 model. The 798c SI comes with an external GPS antenna and the 798ci SI has an internal GPS antenna.
The software upgrades are specific to the type of antenna the unit has.
The cost of each model is the same.

[matt888]

Thanks for the real clarification Wayne.

Too bad I bought the store demo for a discount and had no idea there was a 798c...  I would have preferred to have had the external gps antenna being that I have to flush mount it in my center console.  Oh well... guess I get to spend another 150 bucks 

[Wayne P.]

Matt, try the unit without the external antenna. It may work just fine of no metal is blocking the internal antenna for receiving the satellites frequencies.
I know guys that have external GPS antennas just hanging under their boat consoles that work OK.

[matt888]

That's the plan Wayne, but when I ordered the "Unit Flush mounting Kit" from Humminbird last night, documentation online said the kit not for internal units.  I'll give it a try first before ordering the antenna.

I'm hoping it will work fine because I have a canvas t-top on the boat.