Optimal Setting DFF1-UHD w/ B275LHW

[Moonzy1]

Trying to dial in my finder w this setup.

Fishing in 100-500' using for separating Tuna from bait balls.

Looks kinda all mashed together vs what other guys are getting w similar setup.

pics attached two of mine and one of buddy screen. same day same area, bait and fish.

 

[Snips]

Moonzy1,
Airmar doesn't make a 265LHW so if you are trying to compare the HF side of a 265 (4 degrees) against a 275 (20 degrees) that may explain what you are seeing. Below are a couple of screen shots when we tested them side by side.

Snips

 

[Moonzy1]

that was a typo.
its a. 275

 

[Snips]

Moonzy1,
For me, the best way I found to compare is to have both sounders side by side so they are looking at the same targets. I have tried to compare screen shots from vessels in the same area but have found they haven't been apples to apples. A vessels speed plays a big part on how bunched or stretched targets will appear. Below is screen shot we took early on comparing the same fish targets at the same speed and as you can see they are pretty similar. Here we were using the LF size of a 265 as the 275 wasn't developed yet. I am still curious on your HF as the tail on the bottom doesn't look like what I am used to seeing with the HF side of a 275. Can you post a screen shot showing both the LF and HF at the same time?

Snips

 

[Moonzy1]

Thanks Snips

Sure, next time im out will post pics pf both.

So here is some more relevant info I should have original posted.

Gain on manual - 60% - (maybe too high?)
Gain when in fishing mode doesn't seem to be powerful enough to mark effectively.

Scroll speed was 1/1

Troll speed 5kts (same as speed of boat in top pic)

Clutter 0

TRasnmit Power max (20 I believe )

THanks

 

[Albiedamned]

Moonzy,
I am also running the DFF1-UHD w/B275LHW.
My screen looks exactly like the 2nd & 3rd photo in your 1st post.
My,
HF gain is set in the 80s.
Scroll speed = Dont remember.
Troll Speed = 6kts
Clutter = 0
Transmit power = Dont remember

I will take some better notes this weekend.

 

[Snips]

Gentlemen,
We are all here to learn correct, and that's the point of this forum to exchange information.
Everybody wants their fish targets to look like what they see in the magazines but when they don't, how can we get them there?

Moonzy1 posted some screen shots. I see some very distinct differences between Screen shots 1 and 2, but I would like to see how many in the forum can pick them out.

Feel free to send me a PM or post your reply here.

Snips

 

[Moonzy1]

Snips
Assuming you are talking about the pics in my original post and screen shots 1 and 2 being the top 2 pics?

1. Top pic has very little red signal in it
2. Targets in top shot are thin and clean and long. Easy to distinguish bait from predatory fish. My 2nd pic the targets are short fat and blobbed together w lots of red signal. Very difficult to ascertain what is what.
3. Top pic displays the ocean floor flush w the bottom of the screen and my shots have a space below the sea floor

 

[Snips]

Moonzy1,
You really need to have these screen shots side by side, when you do the differences stand out.
1. Is the depth of the seabed 142ft vs 220ft. I can only assume depth scale was set around 150ft on one and 330ft on the other. Why is this so important? The TX/advance rate is not equal. I did a test on my UHD setting the range at 150 vs 330 and saw 3 minutes of history at 150ft and 6 minutes at 330ft. So just having the depth ranges difference changes the length of all the target by 50%.
2. Is the depth of the fish targets. Even if they were being display differently they would appear at the same depth range.
3. Is the detail of the sea bed itself. Here you need to look at the peaks and valley's of the bottom. We know that the UHD is going to show a more compressed picture but even if we double the distance they still wouldn't match. Two things will cause this, the transducer beam width and/or the speed of the vessel. If we assume that both sounders were using a B275 then the vessel with the UHD was going faster at the time of the screen shot.

This is why it is tough to compare screen shots from different vessels and why we do our testing using side by side transducers when we are comparing sounders.

Down the road I think you can improve the UHD by using a shallower range for the depth. Also use a little more gain and adjust your Clutter. I normally run the Clutter in the 30-50 range, for most this may make the targets appear to hot but I don't mind seeing a little clutter on the display.

Snips

 

[Moonzy1]

Thanks Snips
quite the test rig there

 

[Moonzy1]

ive started over and reset the sounder settings from the MFD as well as a hard reset on the DFF1-UHD.
Figured Id start form scratch.

Looks like there is improvement already. I had upgraded my transducer form a B265LH to a B275LHW and didn't realize you needed to reset the sounder when changing Ducers.

Hopefully this will get me starting from the rt spot and I can tweak settings from here. Will post new pics when I have them.

 

[Pthein]

Make sure and post up a picture or two of the improved picture so those of us following this issue can see and learn.

Thanks

Phil

 

[Moonzy1]

So finally got back out and into a situation I could dial things in a little.

So first off I reset the sounder and all settings on the TZT2 to make sure I was starting w a clean slate.

I think that helped all on its own because I had not reset the DFF1-UHD when I went from a B265LH to a B275LHW.

Here are a cpl of pics of bluefin feeding on sand eels w settings on Fishing mode and trolling at 5-5.5kts. All settings on auto and default.


Pics are not bad. I have good target response and very clean boomerangs

 

[Moonzy1]

Then we were catching fish at a rate that was not commensurate of what I was seen on the (or shall I say lack of) screen.

Raised the gain to around 75 and the whole thing lit up w life.
all other values are the same

Up in the the tower it was easier to use w a white background.

left clutter at zero.

For my purposes using bottom zoom and HF worked best. I was only in 115' of water. Didn't see the advantage of running both frequencies .

on the screen where I raised the gain, you can see the first half of the screen is auto and it lights up when I raised the gain. Fish in the column immediately showed up and I was able to see single sand eels and smaller bluefin down on the bottom. Amazing difference

 

[Snips]

Moonzy1,
Thanks for the screen shots as it looks like you are making progress. I think you are still missing a lot of water column targets however if you Clutter is still at 0. Try this, increase both LF and HF Gain offsets to +10. Use a little more Gain than what you are used to using. Instead of using the Gain control to give you a clean display, try using the Clutter control. I think you will see more targets in the water column.

Snips

 

[Moonzy1]

awesome thanks Snips
will try sat and get back

 

[Moonzy1]

quick question snips

what does the gain offset do for me if I am only using HF?
I understand how I can potentially see more targets by increasing gain manually and raising declutter. But what is the advantage of offset?

I say that because I am typically fishing in 300' or less for bluefin and when canyon fishing in deep water usually only watching the top 300' anyway

I have an R509 to see down deep when needed

thanks

 

[Moonzy1]

Dd you mean TVG? instead of offset?

 

[C-Bass]

Good morning Moonzy,

With the 275 and the wider beam, especially on the High Frequency, you can use gain offset to help the effects of attenuation. The gain offset will help increase or decrease the front panel gain. So say your HF Gain Offset is set to "0" and your Front Panel Gain is set to 5. If you increase the HF Gain Offset, your front panel gain set at 5 is higher and much hotter. 5 is the new 7,8 etc. with an increased gain offset.

 

[Moonzy1]

ah gotcha
so the offset is Kid of like a preamp? Give you a higher input level on your gain control ?

I was reading up on TVG too...My approach after I get gain up and balanced was going to be to bring the TVG up to push the gain down into the water column for better deep returns.

Is this correct logic?

thanks