1650DF fish finder (?)



I have a model 1650DF combo GPS and echo sounder.

I can't call it a fish finder 'cause it never sees/locates fish.
It finds the bottom just fine. And I catch fish because I can
find strutcure, but it never locates fish. I have played with
the sensitivity, freqs etc. Still nothing

Originally it had a transom transducer. I became convinced
that was the problem, so I put in a through-the-hull transducer
and still nothing---it works the same.

Is this unit known for such issues? I see these great
displays from fish finders showing all the fish arches
but this unit shows nothing.

Love the mapping and the navigation. I never get
lost. It never has failed I always know how deep it
is but never see any fish.

Several questions:

A) what am I doing wrong??? Transducer is mounted nicely...

B) if I am not doing anything wrong, is there a replacement Furuno
unit that I could use that is better and can use the same through-hull
transducer? Maybe a unit with fancy, new DSP ?

Thanks for your email. One thing you didn't mention was how deep you were trying to use the sounder. The GP-1650F was a 600 watt machine and depending on the transducer you were using probably has fish detection to the 300ft range. Below is a screen shot of its bigger brother the GP-1850F with a 600 watt transducer out salmon fishing.100_5750.JPG One suggestion is to set the SL and Clutter to 0 and use more gain than you think you should use, notice how much blueish clutter is on the display. Once you start seeing fish targets, use you SL and Clutter controls to clean up the display. Hope this helps.

Thanks for the response.

I am typically fishing in 200' or less of water. Usually
just around 170-210'

Out on Jeffries Ledge for cod and haddock so they are near the bottom.

I just bottom painted the boat and am putting it in for the season

The second part of my question is: Given that the boat will be
in the water and I I don't want to mess with my thru-hull transducer
(ie I don't want to install another one)

Is there another unit I can swap in? Or if not replacing my 1650 completely,
is there a pure fish finder unit that I can put next to the 1650 that will use
the transducer and keep the 1650 for GPS?

The GP-1650DF used our standard 10-pin transducer plug, so yes it is compatible with our current models. The FCV-620 or 585 would be a good choice if you are looking for a stand alone unit.

Thanks Snips,

I think I am going to opt for the 585.
I note that the power is switched by selection
of transducer. Am I still going to be not seeing fish
because of lack of power?

Or does the 585 have sufficient "DSP smarts" so that
even at 600W it has good/better Signal to Noise ratio
than my 1650. What I would really really really like
would be to find a loaner unit to just try.......
The 585 impedence matches to the ducer for the proper output power. The 600w/1Kw in the menu is not for power but the ACCU-FISH function. In my humble opinion power isn't as important as a good transducer. Below is a screen shot from a test I did with the BBFF1. I wanted to take a sounders power out of the equation and show the difference that a transducer can make. 19 vs. 46.jpg The standard 600w transducer uses one element and the power is spread out over 40 degrees (50Khz), this element pulls double duty by resonating at both 50 & 200Khz. For this test I ran the same 600w into a 1Kw transducer that uses seven discrete elements for 50Khz and one for 200Khz. The beam angle for this transducer is roughly half (19 degrees) which means you are focusing the sounders energy in a smaller area. I didn't change any of the sounders settings, just change the ducer.

Yes the FCV-585 is a better sounder than the GP-1650DF was.

Just ordered the 585!!

I would have loved to try it first, but
I think with the 1650 telling me where
to go and the 585 telling me where to fish
I will be all set (I hope)

I will report my opinions/reviews when I
have had it out for a few trips.

Thanks for the advice.
The FCV-585 has a great track record so I am pretty sure you will like it. If you have a chance take some screen shots for us.