Genetron GT-9 vs Humminbird 777c2 vs Vexilar Edge 3

[LWinches]

I finally got a Genetron. It sure is a big box. Tried it out today. For the most part today was uneventful. This was my first experience with the Genetron so I’m a novice with it. That needs to be taken into account. I’ve very experienced with the Hbird and Vexilar and know how I want everything set to fit the conditions. The fish I was seeing were up off the bottom and all three units marked them well, working water from 20-40 feet deep. The 83 Khz on the Hbird works well at this depth as does the 107Khz on the Vexilar and the 120 Khz on the Genetron. The 107 Khz on the Vexilar and the 120 on the Genetron produced interference for each other. I expected that so I only used the 400 Khz on the Vexilar if they were both on at the same time.

Now getting to the point. I’ve never had a unit that would mark fish dead on the bottom. My experience is that all of them have a dead spot from the bottom up for a distance that increases with depth, incline, and cone angle. Well, I accidentally caught a 17” largemouth bass and this gave me an idea. I went over to the bank and got a flat rock. I took a plastic drink container and cut the top off, then cut it into the shape of a “U”. Using some string I strapped this to the flat rock and put the bass into the “U” and strapped him in. This was to assure that the fish was in his normal position and not laying on his side. There would not be any space between the bottom, the rock or the fish. Prior to doing this he suffered brain damage and so was immobile, but his air bladder was intact. I gently lowered this contraption to the bottom and placed a buoy marker. The water was 40 feet deep, 56 degrees.

For the next hour I made pass after pass using the different fish finders, varying the settings to determine if any of these would show this fish. I knew he was there and I new where he was. I tried Zoom, bottom lock, varied the sensitivity. I could find this fish with all three units using Zoom. The problem was, the only way that I knew it was a fish was that I put it there. Otherwise I would have just thought it was a rock on the bottom. Fish symbols, alarms, etc did not indicated it to be a fish.

I’ll repeat this later and experiment some more trying some additional settings. Vexilar has a Clean Line control that I did not use. Suggestions from any of you are welcome as to what settings would give the best chance of showing a 16-18 inch fish ON THE BOTTOM. More important than showing it is knowing what you are seeing is a fish and not just a bulge on the bottom.

L.Winchester

[Btfrk]

I think Genetron has white line also, it may be called clean line? You may also want to try bottom lock to flatten out the bottom? I doubt you will see much more than a bulge on the bottom. These are great tests you are doing you should video tape this and sell it! This type of test will put all the claims to rest and is needed to seperate out the hype.

[LWinches]

Btfrk,

Thanks for the encouragement. I'd rather one of these electronics companies send me their stuff for free and let me test it for them. Nobody makes one that has all the features that I want.

I want:
1-The clean screen of Lowrance HDS, 5 programmable buttons, ,mode selections, adjustable ping
2-Humminbird's fish marks, scroll speed, wide real time sonar (actually I want it wider than theirs), menu system, PRICING, after warranty repair policy, transducer options
3-Vexilar's dual screen, frequencies (107,400), adjustable pulse width, buttons on front, mode selections, tech support.


L.Winchester

I appreciate the work that you are doing comparing the different sonar units. The issue of the dead zone is critical to how any sonar unit works. The dead zone is purely a fact of physics that cannot be overcome easily. The dead zone has huge implications for those who want to find walleyes right on the bottom. Suspended fish aren't as much a problem (As long as they are suspended high enough to be out of the problem area.

Vexilar has a good graphic explanation of one example of the dead zone on their website. I'm sure you have seen it:

http://www.vexilar.com/pages/support...ticle_006.html

If you read the text, the problem is worse with the wider angle transducers. That's why the very narrow 9 deg sensors work so well for the ice fishing we do in Minnesota.

Depending upon the depth and the transducer angle, the dead zone could be a couple of feet up from the bottom even on fairly level bottom if there are bolders or even sporadic weeds present. Anyone who has spent some time icefishing and watching the sonar show the tiny jig as it approaches the bottom and then feeling it hit the bottom knows there is a indeterminate area where you neither see the jig or feel the bottom.

Dead zone, cone angle, screen update time,screen resolution and the ability to show shades/or colors (to represent the data), ping rate, processing lag, front end sensitivity and noise all have a major role in how sonars work. All manufacturers have to make some trade off in order to be able to make a unit that can be sold.

I know there are many who believe that sonar is detecting the air bladder in the fish. I'm not sure that is the case. Some day I'm gonna take a balloon with me when I ice fish and do some experiments. I'll vary the amount of air in the balloon, etc.

Did you ever turn the Humminbird sideiaging sensor on its side and do a bottom scan. That would be a step in the right direction to minimize the dead zone under the boat.

Keep up the reporting. The ice on our lakes is still measured in feet.

Vern

[LWinches]

Vern,

You're definitely right on target. I went to the Vexilar link you posted. You and they do a better job explaining this than I do. You also included some additional factors beyond what I was counting as having an effect on the "dead zone" and I think you are absolutely correct. Thank you.

I never have understood or necessarily believed this air bladder concept. A Rapala #9 balanced jigging lure sure shows up well and air has nothing to do with that. But also, air bubbles show up well too.

Steve Fellegy send me an email and his phone number. After a couple of phone tag attempts we hooked up today. He gave me some great tips on using the Genetron. Thanks Steve. It was very nice of you to take the time to help me.


L.Winchester

[Btfrk]

I am impressed that 20 year old technology of Genetron and 10 year old technology of Vexilar can hold their own against the modern technology of Hbird and Lowrance. I know Lowrance is not in this test but you claimed in previous tests that Vexilar did a better job than Lowrance for fish close to the bottom.

I do not think modern microprocessors matter much in sonar perfomance, they help most with features. Flashers have been around for 40+ years and they do not have microprocessors.

I worked in the electronics industry about 15 years ago with a engineer that developed a video sonar. He actually cranked out a formula that could predict target seperation and the biggest factor was pulse width of the sonar. He explained that the narrower the pulse width the more listening time the sonar had for the echo return. This is only one of the key factors. Cone angle is another, like VernH stated a narrow cone angle concentrates the beam on its target and not on other objects in the area.
That is why I think Vexilar's 400khz (fast carrier, can have narrow pulsewidth) and 10 degree transducer cone is going to be tough to beat on paper. Still another factor is transducer quality and the sonar receiver sensitivity and the ability to make everything work together, kind of the magic part of sonar. This area may be the Genetrons strong point. Only further quality non biased tests from LWinches will help find the better performing sonar.

This is only my observations and opinions I have developed over the years and I go back as far as playing around with paper graphs, which were better than any LCD that replaced them for years to come.

Originally Posted by Btfrk

I am impressed that 20 year old technology of Genetron and 10 year old technology of Vexilar can hold their own against the modern technology of Hbird and Lowrance. I know Lowrance is not in this test but you claimed in previous tests that Vexilar did a better job than Lowrance for fish close to the bottom.

I do not think modern microprocessors matter much in sonar perfomance, they help most with features. Flashers have been around for 40+ years and they do not have microprocessors.

I worked in the electronics industry about 15 years ago with a engineer that developed a video sonar. He actually cranked out a formula that could predict target seperation and the biggest factor was pulse width of the sonar. He explained that the narrower the pulse width the more listening time the sonar had for the echo return. This is only one of the key factors. Cone angle is another, like VernH stated a narrow cone angle concentrates the beam on its target and not on other objects in the area.
That is why I think Vexilar's 400khz (fast carrier, can have narrow pulsewidth) and 10 degree transducer cone is going to be tough to beat on paper. Still another factor is transducer quality and the sonar receiver sensitivity and the ability to make everything work together, kind of the magic part of sonar. This area may be the Genetrons strong point. Only further quality non biased tests from LWinches will help find the better performing sonar.

This is only my observations and opinions I have developed over the years and I go back as far as playing around with paper graphs, which were better than any LCD that replaced them for years to come.

Paper graphs were awesome displays. The horizontal resolution was based on the width of the stylus, vertical resolution was based on the mechanical frequency response of the heating/cooling of the sytlus. If the electronics were truly analog, they could provide incredible resolution. Cost of running it all day became quite high.

All the LCD and Video displays are digitized. Only now are the displays getting close in resolution to the paper graph. The displayed sonar history is a series of pixels (or dots) being shifted to the left. That history is stored in memory which has a finite number of values that can be represented on the screen. The paper graph unit's "history" was a piece of paper with a line that varied in darkness. (Many haven't ever seen a paper graph, that's why I explain it. Early Display sonar units used an 8 bit word width for storage. Memory is now cheap and most use 16 bit words.

Yup, pulse width does make a difference. Again pure physics are involved. The higher the frequency, the shorter the pulsewidth can be. That's why the side imaging sonars frequency are higher. However, higher frequency has problems with water depth. The audio information our ears hear is in a relative low frequency and can get limited information. Pictures are made from light which is very high frequency and that's why they say a picture is worth a 1000 words....

Btfrk, I don't think the fact that modern day units have microprocessors in that is the issue here. (You said," I do not think modern microprocessors matter much in sonar perfomance, they help most with features. The Genetron has two , per a post of the manufacturer back in Sept of last year (per Dick "First off lets set the record straight. The genetron actually has two microprocessors. The genetron is both analog and digital.")

In the thread back then, and still to this day, I have always said that an analog front end is very important. The day will come when some company will build and sell a display sonar unit that will have a front end that matches or exceeds that found in a Genetron. I believe that unit will have a very minimal analog front end (few components) and the rest will be done with a DSP (digital signal processor).

For all anyone knows, that unit exists today but the true greatness of the "front end" may be hidden by a poor implementation in other areas. (the benefit of a dsp based front end is low maintenace, no adjustments.)

The technology exists today to do that. $200 GPS units have analog front ends that have to deal with signals from satellites that are buried in analog electonic noise to where they are barely recognizable. Yet look how great GPS units work now days. Sonar signals are way, way stronger than the GPS signals. The technology was pushed by great demand. So far that demand for a similar sonar front end isn't as large.

Years ago I used a Lowrance X-85 for ice fishing. My friends couldn't believe that it would show an 1/32 oz jig in 40 ft of water but it could if I tweaked the settings and shut off a bunch of the automatic stuff. I don't use that anymore cuz I bought a Vexilar flasher. I don't think the Vexilar is any better in showing fish but it's battery life and ruggedness are definitely better for my purposes.

I've seen many people use some pretty high end sonar units with the settings totally screwed up. Someday someone with get it right. Some of the new units have too many settings that when improperly used can interact with each other.

Vern

[LWinches]

As far as my testing goes, today was a bummer. When I mounted the transducers of the Genetron, instead of using the brackets that came with it, I decided to use some of my own creation. I really believed they would be stronger. They were not. The first run down the lake on plane warped them terribly. I'm not too much for working on transducers on the lake as there is a good chance my tools will end up on the bottom.

Btfrk and Vern. I really appreciate your contributions here. Both of you are certainly experienced and knowledgeable and I am learning from your comments.

I can't make apples to apples comparisons. This would be a test that I cannot perform. From what I understand both Lowrance and Humminbird send their 200 Khz and 83 Khz signal through the same wire to the transducer. If these signals were on different wires I could split them out, and send them to different transducers. Then on the unit set it for split screen. Lowrance does make a 10 degree 200 Khz transducer which should also work on the Humminbird if wired correctly.

For me and my fishing, 83 Khz only is productive in the spring when our walleye are shallow. Most of the year I am fishing from 60-150 feet deep. 83 Khz doesn't perform well at these depths. For most of you that may be insignificant for the depths you fish.

I agree with Vern that the future will continue with a combination of analog and digitial. I think that Lowrance is really onto something with their HDS units. As long as they put enough procesing power in them major strides can be accomplished with a software update. I read somewhere that they run on Linux. I think that is a smart move too.

Gotta go for now and try to mount a couple of transducers correctly.

L.Winchester

[LWinches]

I got several things done today and some questions answered, at least to my satisfaction. First thing, of course, was to mount the Genetron transducers using the mounts that came with it. I made sure they were positioned the same as the others on the transom.

The big question for me is whether or not the Genetron will show fish on the bottom or will it show fish closer to the bottom than other units. While I did not use fish, I am satisfied that using a #9 Rapala Balanced Jigging Lure is reliable in measuring how close to the bottom that a unit will perform.

Test 1 – 40 feet of water.
I drop the jig until it starts to disappear in the “dead zone”. Then I see how much farther it is to the bottom. The bottom was not flat but had an incline. Humminbird 777c2 200 Khz 20 degree cone was 6 inches, 83 Khz 60 degree cone was 12 inches. Genetron 120 Khz unknown degrees wide cone 12 inches, unknown degrees narrow cone 6 inches. Vexilar 107 Khz 38 degree wide cone 12 inches, 200 Khz 10 degree narrow cone 3 inches. On the Humminbird and Genetron I maxed out the sensitivity. I had to back off the Vexilar some to be able to see the screen.

Test 2 – 142 feet of water.
Results were inconclusive. The wind got up. I had the line marked at 140 feet and with the bouncing from the waves it was just too difficult to be accurate.

Conclusions:
I believe I have answered my primary question. The Genetron is no different than other fish finders as far as it having a dead spot at and near the bottom. The factors that determine the size of the dead zone are listed above by me, Btfrk and Vern. All the units would show you more detail using their zoom options but they cannot eliminate the dead zone. I don’t think that not being able to accurately perform the test in deep water has any bearing. The dead zone seen at other depths would only be larger at these depths.

Comparisons:
The Genetron is a superb unit that excels in water 50 feet and less. In water 40 feet and less the very wide cone is superior to anything else I’ve used and is very obvious without measuring. A normal 200 Khz 20 degree cone is only 11 feet across at 30 feet depth. You really need to see more than that. The sensitivity of the Genetron is standout. The echo returns are strong, broad and very easy to see at a glance, while the Lowrance HDS-5X returns were tiny and I had to look closely for them. Vexilar is second best and Humminbird third on this. The A-Scope (real time sonar) of the Humminbird is #1, Vexilar #2, and Lowrance #3. The Genetron did not have A-Scope. The visibility of the jig on the screen is also important to me and the results vary by depth. Down to 50 feet Genetron #1, Vexilar #2, Humminbird and Lowrance (200 Khz) tied for #3. While not measured I would say that the Lowrance (83 Khz) would run a close second to the Genetron. Down to 80 feet the Vexilar #1, Genetron #2, Humminbird and Lowrance tied for #3. Below 80 feet (very noticeable at 100 feet) the Humminbird is #1 with the jig always shown on screen, The Vexilar, Genetron and Lowrance all tied for last only showing a barely detectable trail. Stopping the jigging action on them all brought a good image to screen. Sweep speed is Humminbird #1, Lowrance #2, Vexilar #3, and Genetron #4. Sometimes I like a really fast sweep speed. Visibility in direct sunlight is Lowrance #1 by a significant margin. The Vexilar and Humminbird are noticeable better than Genetron. The Genetron is serviceable in direct sunlight, but it is awkward at times requiring you to change your viewing angle.

Additional Comment:
I believe these results were probably more affected by transducers, cone angles and frequencies than the electronics or brand of electronics. I could be wrong. It wouldn’t be the first time.

L.Winchester

[Btfrk]

LWinches,

Great stuff as usual. FWIW Genetron's manual states 14 degree cone angle for the large transducer and 39 degree cone angle for the small transducer.

Which sonar will you be running this season? I am going to run a Genetron for a season to see how I like it. Vexilar's Edge3 may be my next sonar if I do not care for the Gentron.

So much for seeing fish laying in the mud.