Question on Upgrading Navnet1 Sonar




I currently have '06 Navnet 1 with bff1 connected to either B45 or B744 600w thru hull ducer.

I want to keep my Navnet 1, but enhance my sonar capability as much as possible.

The dff1 seems to be a no-brainer, but can the older Nav1 & dff1 support new ducers like the ss270w and b271w? I can't tell anywhere in literature.

I typically want to mark fish from 0-300 feet offshore for tuna and marlin, so I'm thinking a wider beam would be better and 1kw & 200khz gives me more resolution.

Can someone from Furuno confirm?

If I can use one of these modern ducers, do I need any other special plugs or boxes to do this or do I just need to order dff1 and ducer w/ 10pin plug.

Welcome Pat-
The 22270W transducer with a 10-pin plug is sold by Furuno as a 556TID-HWD. I could not find the cross reference to the other number though.

I’d like to make a suggestion that might save you a bit of money at the outset of your upgrade. The BFF1 has an internal jumper that can be set to 1kW. The BFF1 will support all 10-Pin transducers so perhaps you could change the transducer and internal jumper first. It might be all you need for your use. You could always change to the DFF1 later.


Thanks, u saved me some dough. Is the internal jumper easy to find and change? Do u have a diagram?

So all I would need to do is purchase new ducer and plug into bff1 and I'm all done.

What do I lose by not converting to dff1? I thought the dff1 would give me better rez?

While the DFF1 has digital processing, I feel a better transducer will provide you with the improved performance you are looking for. Like I said, you can always change to the DFF1 if you want, but first try the new transducer with your BFF1. Here is how to change it to 1Kw:

3.1 Selecting the Transmission Power
The default transmission power is 600 W. If you install the 1 kW transducer, change the
jumper connector to #3-4 from #1-2 on J12 as follows:.
1. Detach the power cable from the connector.
2. Open the cover of the ETR-6/10N.
3. Remove the jumper connector on J12 by using long-nose pliers.
4. Insert it to #3-4 pins of the J12 for 1 kW transducer.
Note: Do not insert the jumper connector upside down.

You can find the manual to the BFF1 on line by searching under previous products.

Hi Melville,

Before I buy new ducer, I want to make sure my tap settings are correct on my bbff1.

We have either a b45 or b744 ducer and have never been able to read bottom below 400 feet.

What are the correct tap settings, can u provide diagram? Anything else on the bbff1 I should check?
The following is a link to the BBFF1 manual. The BBFF1 is also known as an ETR-6/10N. ... Manual.pdf

In section 3.1 you will find the diagram showing where to find the output power settings. The default of this sounder module has always been 600w and I’m sure yours is set to that. If you output 1Kw out to a 600w transducer it won’t last long.

If you are still having problems you might want to call our technical support group at 360-834-9300.