R109 sweet spot? DFF3 and TZT14

Panhandler80

New member
Good morning,

Boat I bought has a pair of Garmin 7912XSV units with a B275LHW. I think that set up would be fine for looking for bait in moderate depths and picking apart schools for fish with the frequency sweep feature. I'm going to leave that system in place for THAT purpose.

I also need a system to more accurately discriminate bottom in average depths (say 100-300) with a narrow H beam. In addition to this, I want to accurately read bottom out to 1,500 or so for deep dropping (could still use H on R109 for a lot of this... especially if I dial fixed frequency back a little)... AND I'd like to try and mark deep scatter layer and / or swords out to say 2,500-3,000 feet... which would be my R109 in L. I figure for this second system my TZT14 (already own), and R109 and a DFF3 would work well. I realize that the TZT will not process 2kw CHRIP from any sounder, so... my questions are this:

1. Does anybody know what the sweet spot frequency wise for the R109 might be? Ideally I'd like to set the frequency (again... SET as in fixed since the TZT won't recognize 2kw sweep) to something outside the frequency range of the B275LHW that's on the Garmin.

2. Should I even worry about setting the fixed frequency on Furuno outside the sweep range of the Garmin?

3. For the intended purpose of my Furuno unit, wouldn't the R109 be my best bet? Is there a transducer that I'm over looking?
 
Panhandler80,

If you are considering using the DFF3 and have it networked into your TZT14 Multifunction Display, I would choose the following operating frequencies for the R109LH (after having it set to either 2 or 3 kW TX Power with the DFF3). Set the DFF3 to use 35 kHz for the Low Frequency, and 120 kHz for the High Frequency. Both these frequencies are in the optimum “sweet-spot” frequencies for the R109LH and will provide you with the depth and resolution that you are looking for.

Also, by using those frequencies for the DFF3/R109LH they should not interfere with the GARMIN 7912XSV that is using the B275LH-W’s operating frequencies of 42-65 kHz for Low Frequency and 150-250 kHz for its High Frequency.

- Deep Blue :ugeek:
 
Thanks for the response.

But, it looks like R109 can operate at 38-75 and 130-210, So I don’t think those frequencies you suggested are an option.

B275LHW is 42-65 and 150-250. Again, my understanding at least.

When you say sweet spot what exactly do you mean? A frequency that tends to pick up intended targets very well? I spoke with air more today and they say from the functionality standpoint no one frequency works any better than another. Obviously certain frequencies pick up certain targets better understand that.
 
It sounds like you’re saying to set the DFF3 at a certain frequency. I did not know that was an option. If it is then duly noted. What frequency should I fix at tzt for finding typical Bates and fish? I cannot take advantage of chirp with a TZT. So set the DFF3d like you said, and then what? My thought was to put my low at 38 or high 60s. And then my high at say 140. As those are both frequencies outside of my chirp range. On the Garman.


Truth of the matter is each system is set up or something entirely differently and they won’t always need to be used at the same time anyway. Wish I could do chirp in to kilowatt on the Farino but that’s not an option with a TZT
 
Panhandler80,

I'm a little confused by your current posts, particularly when it comes to the DFF3 and the DFF3D. These are two completely separate sounder modules with different operations and features. And since the TZT14 doesn't have an internal sounder, you would need to connect an external sounder module like following:

BBDS1 This is a 50/200kHz network fish finder used for NavNet3D, NavNet TZtouch and NavNet TZtouch2. It features the bottom discrimination function that determines the bottom structure and separates them into the following categories: mud, sand, gravel, and rock

DFF1-UHD is an external chirp sounder module for NavNet3D, NavNet TZtouch and NavNet TZtouch2. It features a Chirp sweep pattern across 90 frequencies (50 kHz +/- 20 kHz, 200 kHz +/- 25 kHz)

DFF3 This is external sounder module for NavNet3D, NavNet TZtouch and NavNet TZtouch2. It features selectable 1, 2 or 3kW output power, with the ability to choose two operating frequencies from 28 to 200 kHz with FFS (Furuno Free Synthesis) technology. This is the unit that the R109LH Transducer would connect to.

DFF3D This module is the Multi-Beam Sonar for NavNet TZtouch, TZtouch2, and TZtouch3. This unit utilizes a special transducer with fixed frequency of 165kHz, and provides a 3D Sounder, Side Scan Sonar, Cross Section Sonar, and Triple Beam Sounder.

So are you planning to use your TZT14 with the DFF3 that will be connected to the R109LH Transducer..? :think

- Deep Blue :?
 
Dff3D a typo. Meant DFF3. I had a DFF3D and DFF1 hooked up to my TZT14 on my old boat, and I had a screaming baby in my ear last night. Phone-pecking fingers and muscle memory got away from me.

You had mentioned fixing the R109LT to two frequencies that THINK are outside the R109LH range. That was one question I had.

The other, and I now think I know what you meant, was when you said "set the DFF3 to X frequency." That statement had followed your instruction to set the DFF3 (manually) to 1kw, 2kw or 3kw. I think I took the frequency setting to also mean literally at the black box. You were talking about picking a fixed frequency FOR the DFF3, but doing so with the MFD electronically. Duh.

Another question: Just as a fixed frequency interferes with the sweeping machine, the sweeping machine will interfere with the fixed machine just as often and at the same time. I'm pretty sure of that. Does the fact that one is 1kw and one is 2kw matter? In the fishing scenario where both were running, it wouldn't bother me one bit if the 2kw walked over the 1kw and the 2kw was left un altered. Thoughts on that?
 
Panhandler80,

Power doesn't matter as much as frequency does. You can set the DFF3 for Transmit Power to 2kW, and then set DFF3 for the fixed Low Frequency of 35kHz, (or 38kHz if you prefer), and set the fixed High Frequency to 120kHz (or 130kHz).

We have tested the R109LH to these frequencies (35kHz and 120kHz) and they will work. I'm using 35kHz and 120kHz as an attempt to give you some decent frequency separation and keeping both the sounders from stepping on each other.

-Deep Blue
 
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