[TG] [TG11] Element 7 HV100 Mounting Interference

[TokyoTitus]

Initial run of my new Element 7 HV100 uncovered a couple of potential problems. The transducer is mounted on a mounting plate beneath a kayak. Two zip ties were used on the transducer for additional security. The remainder of the cable is coiled and stored in a compartment area just above the transducer, but is still mostly submerged. All issues were found duing use in depths between 180 ft and 500 ft.

Potential problems are:

1. Auto depth will sometimes (lets say 80%) keep cycling through a range of depths. This happened with both 1.2 ghz and 355 hz. All 3 options (gain etc.) were in auto mode, although I did not try a system reset. Setting manual depth proved more beneficial since the depth did not change often. But I would prefer the auto function for simplicity.

2. There was a lot of surface noise, which was not so much of a big deal using traditional / CHIRP sonar. However, it made 3D completely useless since it cluttered the screen so much. 3D was tested between 50 ft and 200 ft with the same surface noise results. I do use a small 2.5 outboard on my kayak which could produce the noise while under way, but the noise was steady even when the outboard was shut down.

Could the mounting of the transducer or close proximity of the excess cable be the culprit for either of these issues? I will obtain new screenshots if the attached pictures are unclear.

[Tom - Raymarine - Moderator]

Hello TokyoTitus,

Thanks for the clear photos, they give us really useful information.

Quote:Auto depth will sometimes (lets say 80%) keep cycling through a range of depths. This happened with both 1.2 ghz and 355 hz.

What sort of depth of water was this in, and on what channel?
That is normal when the sounder is on the limits of the usable signal-noise ratio range, when the sounder is having trouble being sure what is the bottom echo and what is (normal) background noise, typically when you're at the extreme end of the depth range for that channel. Using manual range overrides the dependence on the display being able to say for sure that the depth is n feet.

Quote:There was a lot of surface noise, which was not so much of a big deal using traditional / CHIRP sonar. However, it made 3D completely useless since it cluttered the screen so much. 3D was tested between 50 ft and 200 ft with the same surface noise results.

Do you have any images of the 3D performance when in those depths? The only 3D image you have attached seems to have been in 500ft of water which is the deepest I have ever seen an Element produce a 3D bottom profile, and which is over 50% deeper than our maximum specified depth performance for that channel (300ft.)

On the Sonar channel, that sounder image looks perfectly normal for that depth. In order to have the best chance of picking up targets of interest down towards the bottom the system increases the gain automatically so that the background clutter is only just kept off the screen in the lower part of the water column. Because the echoes from nearby targets are of course stronger than from further ones this does lead to a higher chance of clutter higher up in the water column, which the Surface Filter can help attenuate. The Auto SF is removing some of this in your image I can see, but if you would like to remove more you can increase the SF setting. Don't put it too high though as you can suppress wanted returns in the upper water layers - my preference is always to see the clutter and the fish within it than hide the clutter and risk missing fish too.

If you would like to see a clearer, crisper image in these deeper waters then there are of course more powerful sounders available, but not at Element's price and outstanding flexibility of sounder channel options.

The short answer: your Element is doing everything it's supposed to do, given the depth of water, and you don't have an interference problem to worry about (that is present in these photos anyway.)

One final thing: if you can, losing the zip-ties would be good. They may be blocking some of the sounder ping energy, even placed at the ends of the transducer like that. The transducer is this length because the acoustic elements run almost the full length.

Regards,
Tom