New to TZT3 troubles dialing in bottom machine.


New member
Tzt3 w/B265LHW and Ddf3d bb. I have many years of experience with this transducer on my old Simrad Evo3 and never had any issues. This makes me think I'm just not doing something right.

Typically, I'm fishing 70-150'. I run HF 200hz and zoom to the bottom 20-30'. I'm able to see the tailings differentiating a sand/soft bottom from the limestone/rock bottom, so that's not the issue. For some reason, it's like all fish returns are filtered out. That's the best way to describe it.

If I split and use dual frequency, the LF side will mark fish great, almost like what I'm used to seeing on my old simrad HF 200HZ. I've messed with the TVG, Clutter, Gain.. idk. Didn't make a change. It also marks fish well with the tripple beam sonar.

I run in manual with a TVG of 3. Ping speed all the way up. Screen speed 1/2. Gain I adjust a bit depending on depth. Usually between 15-25.

I tried switching to auto cruise and auto fishing.. screen got washed out like gain was way up. I really hate auto settings.

Any help would be greatly appreciated. 🙏


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Last edited:

Here are some recommended settings that you can try when using the TZT3 with a Chirp B275LHW Transducer:
  • Screen Advance: 1/1
  • TX RATE: “20”
  • Set the HL/LF Bottom Level “-20” instead of “0”. You might have to use a setting of -25”, or even -30” depending on what the bottom looks like, but always start with using “-20.”
  • TVG: Leave this setting at default. Then adjust once you are on the fishing grounds.
  • Interference Rejection: If you need to use this setting, then only set it for “MEDIUM”
  • Some operators always like to use Black Background instead of the White or the Blue Background for displaying better contrast.
  • Once you have set the unit to all these settings, go ahead and tweak the sounder at the dock to get the feel how the GAIN, TVG, and CLUTTER. (Remember, when using TVG this compensates for Propagation Augmentation of Soundwaves, and it can reduce the effect of surface noise on the screen, so using less of this setting is more...). CLUTTER Controls can also affect the Sounder’s Picture
All fish finders/depth sounders/sonars include a feature that allows the unit to automatically set the Sensitivity (GAIN). The effectiveness of this feature varies widely based on water conditions, temperature, salinity, speed, and other manual settings, including the type and/or placement of the fish finder's transducer.

You can use these following steps will ensure the best fish finder/depth sounder/sonar performance:
  • Bring your boat to the depth that you commonly will be operating the unit, (preferably more than 20 ft). Do not attempt to use these settings in shallow water. As the cone of the bottom coverage from even the best transducer used in shallow water is so small that unit will only be good for showing digital depth.
  • Turn OFF the Auto-Sensitivity (GAIN) feature and turn OFF the Auto-Range feature (you can turn on this feature back on later).
  • Manually adjust the Range to more than twice the depth. If you are in 20 ft of water, then you’ll need to adjust to 50 ft (as 40 ft will not work). You can even set the Range to three times the depth and get the same results.
  • Adjust the Sensitivity (GAIN) so that you can just see a faint second bottom echo, if your depth is approximately 20 ft, then you will see this echo at 40 ft. The second echo occurs because the fish finder/depth sounder/sonar is hitting the bottom of the seabed, and then reflecting up to the transducer again. The presence of the second echo ensures that the full signal is being picked-up at the transducer. If your Sensitivity (GAIN) is too high, then signal will be distorted, and you will have trouble distinguishing between the bait and fish.
  • Re-adjust the Range to your desires depth and then turn ON your Auto-Range feature. Leave the Auto-sensitivity and any Fish ID…OFF (indefinitely).
Periodically re-adjust the sensitivity of your fish finders/depth sounders/sonars unit especially when moving the boat to an area when one of more environmental factors have changed. The optimal Sensitivity (GAIN) depends on these following factors:
  • Water Depth
  • Water Temperature / Density
  • Water Clarity
  • Salinity (this can be critical around the outflows of fresh water rivers and river mouths, close proximity to glaciers, or recent rain storms/hurricanes that have dumped huge amounts of fresh (rain) water, etc.
Boat speed can also change the optimal desired settings. Less GAIN may be required when a boat is drifting slowly in a calm water, than when the boat is trolling or cruising. The signal loss can be so significant that at higher speeds full GAIN could be required to get any consistent bottom readings. For these situations the Auto-Gain features is probably the best bet (as you are probably not going to mark any fish anyway).

I hope you will find this information helpful..? :unsure:

- Deep Blue ;)
Thanks Deep Blue!. Looks like I'll have a few hrs in 65' this Wednesday. I'll report back after. I think it was marking fish ok before in 30-65' just seemed like 70'+ it didn't. Hmm. This was my settings. The only thing I messed with on the ride in was the HF gain offset. I turned it down to -20. Which makes sense why I was able to turn it up to 50-60 and it looked like it did before when the offset was at 0 and gain was at 25-30.. so I don't think that really did anything.

I will run threw your recommendations and report back.
Thanks again!


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Deep Blue,
Want to thank ya again for the tips. Went threw everything as I didn't wire up this boat. There are 4 transducers in the boat. 1 shoot threw is disconnected and not used. 1 is a B54 3D ducer hooked to the DFF3D. 1 is a B60 that is connected to the Tzt3 12" and the last ducer is the B275LHW connected to the Tzt3 16".

So after tracing everything out and going threw all the settings. I found that the 12" tzt had the B60 connected to and the 16" had the 275lhw.. and.. both were on transmitting at 200hz. As soon as I turned the 12" b60 off the screen cleared up and it started looking right.

Today we only made it out to 45-50' but it was marking fish well and was marking bottom great!. I was also able to run the gain all the way back to 0!. And it looked great. I'll be back out in 110-130' Fri and Sat. Will report back how it looked out in that depth.

Thanks for the Help again Deep Blue.


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Hey great news on figuring out the transducer situation. (y) Please keep us posted on how the Fish finder(s) are working for you..?

- Deep Blue :cool: