Thread: HDS8 vs HB997 test results

What you're pointing to is propwash. What I'm talking about is electrical interference. In the pic below I indicated the propwash with red arrows, the electrical interference with blue. The electrical interference shows up as white lines. Only the HB is showing electrical interference, which degrades the display of the bottom and any structure.

Pretty much anytime you have the transducer on the transom you'll see at least some propwash.

Oh prop wash. Guess the Lowrance transducer was mounted further back then the prop?
If you were scanning over prop wash it would show on both sides.

Originally Posted by mduncan62

Oh prop wash. Guess the Lowrance transducer was mounted further back then the prop?
If you were scanning over prop wash it would show on both sides.

That's not the way it works. Propwash occurs a short distance ahead of the prop as well as behind it. If the transducer is mounted to the left of the motor then the propwash will appear in the right hand view. If the transducer is mounted to the right of the motor the propwash appears in the left hand view. Anyone who has run si can tell you that what you're seeing is propwash. If you just look at the pics I posted earlier you'll see that there are no white interference lines because there isn't any electrical interference and consequently, a much better view of the bottom and structure. The first two pics I posted don't show any propwash because my transducer is mounted off the right side of the boat well ahead of the prop. I retract it when running any faster than 5 mph. In the pic I posted from Humviewer, you can see a steady return about 7 ft deep. That's the left hand pontoon of my boat. Anytime the water is more than 7 ft deep, that left hand pontoon shows up in the image. I'm not sure why this interference issue is so confusing for you. There's no question that the HB was receiving interference that the Lowrance wasn't subject to.

Cane pole,

I drink Folgers coffee as well and have a few of those containers lying around. If you would, please give me some specs on your coffee can condos so I can make one myself and see what I can do as far as imaging with my 998. i.e. diameter and length of pvc pipe. Container filled with gravel? concrete?

Thanks

Originally Posted by TN Hillbilly

Cane pole,

I drink Folgers coffee as well and have a few of those containers lying around. If you would, please give me some specs on your coffee can condos so I can make one myself and see what I can do as far as imaging with my 998. i.e. diameter and length of pvc pipe. Container filled with gravel? concrete?

Thanks

I have my Transducer mounted directly in front of the prop, and I don't get prop wash if that's what you want to call it. In front of the prop to me would not be prop wash, sorry we'll just have to disagree. And since you know the low product so well, can you show me what elect. interference looks like?
Every HB I've owned had interference problems, maybe the guys from apple can fix that for HB like they did the new iphone.

Scanning for a boat, is a lot different from 3 pieces of PVC sticking out of a 12 inch folgers coffee can. IMO. Tires also will give a much different return.

Canepole, is it possible to get a pic of the transducer placements on the test vehicle?

Here is what prop wash looks like on Low. This is first time out, 20ft of water, brushpile and fish right next to a dock. I partially ran through the area a couple minutes before going back by.

CP's pick has a distinctive white line running from side to side on the Low pics. This my friend, is interference.

Originally Posted by Cane Pole

This is billbob's unit. Mine had hash, but after I installed the power filters provided by HB, the hash went away. We turned off all power equipment and all electronics on billbob's boat, but it still had some hash. I don't have a clue what the problem might be. I also ran the internal select filter to hi2 with no results.

Apparently CP is aware of the interference.

I'll build my pvc condo and we'll revisit this in a month or so.

It really doesn't matter what the target is. It's obvious that the hb is receiving interference, take a look at pics posted by others and you'll notice the absence of the white lines or noise.

Surely you don't think the prop has no influence on the water just ahead of it?

Originally Posted by TN Hillbilly

Surely you don't think the prop has no influence on the water just ahead of it?

I surely don't think that it's going to screw up the reading on an SI transducer. I would contend that the hull of the boat has the most influence on the water in front of the prop.

I'm sure CP will have more results in under 30 days, but I'd like to see your's also.