Dual FishFinder Interference

[jerrypark1]

All,<br />I've gotten great help in the J/E motor forum, so I thought I'd bug the experts in this forum too. I have, quite possibly, the ugliest boat to ever grace a waterway, but it hauls in the fish like no-man's business. It's named "The Nappy Goose". The boat came with an old Humming Bird finder that is less than optimal, so I bought and installed a new Lowrance 126DF (50/200kHz). The plan was to use both finders at once....the old one for the trolling motor driver up front to keep on path, and the new one for the guy in the rear looking more closely for bottom structure, fish, etc. Well, they interfeer with each other and neither will work very well while the other is on. Now I know I'm getting picky, but using only the 50kHz in the back is not much of an option since we're usually in ~50ft of fresh water. My question is whether there is any remedy, or a combination of settings I can use to get both operating at the same time? I'm guessing not, but just wanted to ask. If there is no remedy, I'm considering replacing the Humming Bird and getting a new finder up front. Preferably one in the 192 or 384kHz range. I'm hoping that 192k is far enough from 200k that they wont interfeer.....anyone out there with experience or opinions on this. It needs to be cheap and basic since I only need it for general depth and structure. I've seen an Eagle Ultra Classic at 192kHz at Cabelas online for $99, would this work? Or even an old Lowrance x-70a (192&384kHz) on ebay for $150 range. All opinions welcomed and many thanks for helping out.

 

[18rabbit]

Re: Dual FishFinder Interference

What you are experiencing is exactly what is expected with two sounders working on the same frequencies. For shallow water you can run a 200kHz transducer and a 233kHz transducer at the same time. The frequency spread is far enough apart they will not interfere with each other. I don’t know if 192kHz is far enough from 200kHz. Also, regardless of frequency(s), mount the transducers no less than 18-inches apart.

 

[jerrypark1]

Re: Dual FishFinder Interference

Thanks for the info....what/where can I get a finder at the 233kHz range? I've never seen a finder with that option as all are usually in the 50/200kHz frequencies. As you can easily tell, I'm far from the most knowledgable on this, but I thought the transducer AND finder needed to be synced up with respect to frequency. It couldn't be as easy as getting a 233kHz transducer for the Humming Bird, could it??? I would be fine with any loss of detail, gain, etc. on the Humming Bird if that was at all possible. If that's not an option, I'm up for anything in the sub-$200 range that will work for a new or used finder replacement. Thanks again for the info, I love this forum.

 

[18rabbit]

Re: Dual FishFinder Interference

Yes, the transducer and the head need to be frequency compatible. No, you are not likely to find 233kHz on a Humminbird. I don’t know about other sounders. I have it on a low-cost Furuno sounder model RD-30. It’s not a fishfinder, it’s a remote display that accepts as plug-n-play an Airmar 233kHz transducer. If you want you can plug GPS into it, too but there it is not a chartplotter, just a little display.<br /><br />I have a separate 38/200kHz fishfinder and the Furuno RD-30 is a 233kHz backup shallow water sounder.

 

[eurolarva]

Re: Dual FishFinder Interference

Can you switch to a narrower cone? I run two eagles on my 16 ft boat without any problem. One unit is running on a portable gell cell and the other is running on my marine battery. I believe mine are both 20 degree cones so in shallow water the cross interference isnt as noticable.

 

[jerrypark1]

Re: Dual FishFinder Interference

Thanks to you both for the info. Eurolarva, where are your transducers mounted?

 

[eurolarva]

Re: Dual FishFinder Interference

I have one mounted on the bow with a temp ducer bracket that I use when I am trolling and the perm mount one is on the transom.

 

[jerrypark1]

Re: Dual FishFinder Interference

I'm looking into getting an old Lowrance that works at 384kHz. It is an x70A-3D. Anyone know about this model and if it is worth the time to mount. Also, I'm only guessing that I can run a 200 and a 384kHz sounders simultaneously, anyone know for sure?