Can't read deep bottom with 1871f and TM185M

alphadog808

New member
Hi guys,
I just purchased a Furuno 1871f and mated it with a Airmar TM185M(transom mount). I previously was using a FCV620 with an Airmar p66 but needed something beefier to read 700ft+.

I took it out for a spin yesterday and noticed that while I could read the bottom and water column on shallower spots(150 and beyond), when I started trying to see the bottom(and fish) past 600(can't quite remember) I couldn't see anything. Only when I upped the gain, I could *sort of* see the bottom, but it was so filled with noise, reading the bottom was pretty difficult, much less seeing any fish. This was done at very slow(1 or 2 knots) to not moving at all.

Any thoughts on why this might be happening and what settings might improve these readings?
 
I have the same problem, when I run dual frequency with a p66 and adjust the range I can see a very feint bottom on the 50khz and nothing on the 200khz. I have the added issue of my unit showing lost position periodically for a couple of minutes. Any suggestions would be appreciated.
 
So, I checked a couple things, hoping I missed something. The only thing I noticed is that when I had the TM185M plugged in, the furuno showed my transducer as TD-ID, which to me meant that furuno auto sensed the transducer.

But when I was testing and had the transducer unplugged, it showed a TM150M(??)...so I manually chose TM185M(as now the list showed). When I plugged my transducer back in, it showed TD-ID again, but when I unplugged it, it now shows as TM-185M. Maybe that's it?? I kinda think not, but it's worth a shot to look next time I can get out...

Any other settings that will allow me to crank the gain but clear noise without clearing out fish on the bottom?
 
alphadog808,

1. Do you know what is the current software is for your GP1871F, as It should be version 4..?

2. You should also be able to manually select TM185M (or even select the B175M...) as both these are 1kW Transducers that essentially have the same elements for frequency of 85-135kHz.

3. If the unit is selected for TM150M Transducer, that's only a 300 Watt Transducer using 95-155 kHz frequency, and the GP1871F will not provide enough power for the TM185M 1kW Transducer, and this could be the main reason for weak echoes.

- Deep Blue :think
 
Surf launch":1i3kp9fq said:
I have the same problem, when I run dual frequency with a p66 and adjust the range I can see a very feint bottom on the 50khz and nothing on the 200khz. I have the added issue of my unit showing lost position periodically for a couple of minutes. Any suggestions would be appreciated.

Surf, I think this might be different for you as a P66 is a 600w transducer while the TM185M is a 1k(chirp). I also have a P66 and I start to lose the bottom around 6-700 feet, hence why I upgraded to a 1871f and TM185M. But it seems at the moment I don't see any appreciable improvement...
 
Deep Blue":ld7tkdsw said:
alphadog808,

1. Do you know what is the current software is for your GP1871F, as It should be version 4..?

2. You should also be able to manually select TM185M (or even select the B175M...) as both these are 1kW Transducers that essentially have the same elements for frequency of 85-135kHz.

3. If the unit is selected for TM150M Transducer, that's only a 300 Watt Transducer using 95-155 kHz frequency, and the GP1871F will not provide enough power for the TM185M 1kW Transducer, and this could be the main reason for weak echoes.

- Deep Blue :think


Deep Blue,
I'm running software 1950193-4.0.0R, boot 1950194-1.25.0R, Kernel 1950195-1.33.0R, and rootFS 1950196-1.68.0R. I believe I checked a while back and it's the newest version. It's at least new enough to see/support the TM185M, I believe.

Doesn't seem like I can manually choose the transducer, once it's plugged in, my choices disappear and it just shows TD-ID. If I start up without the ducer connected up, then I can see choices.

Either way, I don't see a spot where I can choose 600W or 1K? I see a transmit power low/high..??

You are correct, the TM150 is nowhere near as powerful(?) as the TM185. I kind of don't think the furuno sees it as a TM150 as I could get depth readings at 1000+ feet, just not see anything even partly decent. I can't even get those type of depth readings with my 600W P66(previous FF).

Thinking about it a little more, I *do* have a P66 running with my lowrance running at the same time...would that be an issue? I kind of don't think so as it runs at 50khz/200khz and the TM185 doesn't conflict with those khz...

I'm just hoping I didn't waste my money as it's not much better than what I had before(FCV-628 and P66).
 
alphadog808,

Good..! You have the latest software that supports the TM185M. So are you sure that you have a Furuno version of the TM185M..? If you have the Garmin version, then that explains why the T-ID is greying out your selection and only allow you the selection the TM150M.

If this is case, either replace that transducer with the correct non-TID Furuno version, or find a way to cut that orange T-ID transducer wire.

Running another echo sounder can potentially cause issues with second, third, or forth harmonics, confusing both the echo sounders. Even if there is separation between frequencies.

- Deep Blue
 
Hi Deep Blue,
I should clarify. It is a Furuno 'ducer. However, when it's plugged in, it shows up at TD-ID and there are no other choices available. Only when I turn it on without the ducer do I now see choices.

It was just surprising that when I first tried it unplugged that I saw it defaulted to a TM150M. I then manually changed it to a TM185M. Now when I plug in the ducer, it does show as TD-ID(and that's it), but when I power up without the ducer, it now defaults to a TM185M.
 
Whenever it properly recognizes the TID Chip, it will automatically configure and there is nothing to do. It sounds like at least once the TID Chip wasn't being seen correctly and defaulted to a manual setting of a conservative low power model. You might keep an eye on that. It should stay with TID.
 
Johnny Electron":y9ra10id said:
Whenever it properly recognizes the TID Chip, it will automatically configure and there is nothing to do. It sounds like at least once the TID Chip wasn't being seen correctly and defaulted to a manual setting of a conservative low power model. You might keep an eye on that. It should stay with TID.

Thanks, I'm hoping that's what it was. But I would think I wouldn't get depth readings up to 1000 feet if the furuno acted like I had a TM150M installed. I guess I'll see the next time I get out...
 
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