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Location: Watersmeet, Michigan | Hi all. Went out to a lake I've fished many times before (only 140 acres) and have the same sort of interference occur to both my Humminbirds every time I go there. It NEVER happens anywhere else. I get a sort of "pulse" on the screen, like the one below in the picture, except that it's very regular - about every five seconds. It's much stronger on the south end of the lake, and eventually dissipates as I move north.
Has anyone seen such a thing before, or have I discovered a window to the Twilight Zone?
Fr. K
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Location: Ludington, MI | Could it be the ELF system? I think that was decommissioned though.
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Location: Watersmeet, Michigan | I wondered about that myself, but I believe you're right and ELF was decommissioned. This is iron country - high grade hematite and magnetite (compasses are about useless). Could a good lode of iron ore do that?
Fr. K
Edited by Yooper Padre 10/7/2015 9:46 PM
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Location: Ludington, MI | I don't know. The DNR has an extensive library of maps that include some bottom soils analysis. You could look to see if there's rock bottom.
http://www.michigan.gov/dnr/0,1607,7-153-10364_52261_52964_66796-67... |
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Location: Watersmeet, Michigan | Just got an email from a friend at the DNR fisheries division. He said they see the same thing at some other area lakes. Has to be iron ore. (Or the Russians.)
Fr. K |
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Location: Mauston, Wisconsin | All bets are off, Padre! The Yooper is the Twilight Zone!!!!!!!! My guess would be a pulsed electromagnetic/RFI source on or near south shore of the lake.
Elf may have been shutdown/closed operationally, but are they maintaining it and sending a pulse signal as a way to keep the system available if needed?
Another source of pulsed EMI/RFI could be electric fences for cattle or dogs, assuming there are homes on or near the lake, these systems all use the earth as part of the circuit, therefore your sonar maybe picking up the pulses as a pulsing current typically is composed of many frequencies within the pulse bandwidth.
Is the lake close to a NWS weather radar location? Or is there an airport close by?
Have fun!
Al |
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Location: Watersmeet, Michigan | There is a summer camp on the south end of the lake that might have an electric fence to keep the kids in. I still think it's iron or Putin. |
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Location: Ludington, MI | Fortune Lake? |
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Location: oswego, il | nice area, I have enjoyed fishing a few lakes around iron river.
Edited by ToddM 10/9/2015 8:09 PM
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Location: oconomowoc, wi | Yooper Padre - 10/8/2015 11:10 AM
There is a summer camp on the south end of the lake that might have an electric fence to keep the kids in. I still think it's iron or Putin.
electric fence to keep the kids in??? what kind of camp is this?  |
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Location: Mauston, Wisconsin | Padre, Given you said the interference is periodic, e.g., approximately every 5 seconds, its not likely geological....its likely a electric fencer or electric dog fence at the summer camp. Do they have dogs, horses, petting zoo, etc.?
Have fun!
Al |
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Location: oswego, il | What are you saying Al, every time that fence finds another ground the padre gets interference on his graph? What kind of camp is that?
Edited by ToddM 10/10/2015 11:01 AM
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| fishhawk50 - 10/9/2015 9:12 PM
Yooper Padre - 10/8/2015 11:10 AM
There is a summer camp on the south end of the lake that might have an electric fence to keep the kids in. I still think it's iron or Putin.
electric fence to keep the kids in??? what kind of camp is this? :o
lol! Anyone got a camp brochure? |
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Location: Hayward, WI | Camp must be full of FIB-lets.
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Location: varies | I can see it now,,, Next years American Horror Story being called "CAMP". |
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Location: Watersmeet, Michigan | With kids like this, a fence is a necessity.
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Location: Mauston, Wisconsin | ToddM - 10/10/2015 11:00 AM
What are you saying Al, every time that fence finds another ground the padre gets interference on his graph? What kind of camp is that?
No, I'm saying that a electric fencer uses the ground as a return path for the pulse, if there's a weed or a insulation failure the pulses follows the earth back to the fencer itself. Even if there is no "fault path" like you peeing on the fence its still generates an electromagnetc pulse between the fence wire and earth. See the link below. Electric fencers cause all kinds of intererence, including telephone lines, internet, TV, guitar/sound systems and yes, I think quite likely sonar. The key trigger for me is the repetitive interference rate and that it becomes weaker moving away from the source.
The first step is to time the interference pulses, e.g., Padre said about every 5 seconds, but is it really 5 seconds? Not all electric fencers have the same pulse rate. This would be first instance that I know of where sonar interference seems to correlate to an electric fencer or similar device. EMI/RFI interference is a complex engineering field and one I'm very familar with as an electronics/electrical engineer.
http://www.arrl.org/electric-fence
Padre: It makes sense that a summer camp would likely have animals like "horse's" etc., so they likely have a electric fencer. It is illegal to cause radio interference. I would approach the camp owner(s) from a more benign perspective, e.g., "I'm trying to solve this mystery that only happens with my sonar on this lake." Its likely very fixable if its a electric fencer issue.
Good luck!
Al
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Location: Mauston, Wisconsin | Padre, Is it Fortune Lake? I looked at the Fortune Lake Camp website - I didn't see any horses or animals in the photo's. It could be one of the lake shore property owners too. If its an electric fencer you can probably find the source using an old fashion AM radio and cruising the shoreline. When it gets the loudest you have narrowed down the search..
"Virtually all radio interference originating from an electric fence is caused by a spark or
arcing across some fence related hardware. The noise can interfere with radio and
television reception and propagate for a considerable distance. In some cases, the noise
can disrupt radio reception for a radius of over a mile from the fence. The interference is
most noticeable on an AM radio and typically heard as a "tick-tick-tick" sound. This is a
somewhat unique characteristic of electric fence noise. " |
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Location: Watersmeet, Michigan | Padre: It makes sense that a summer camp would likely have animals like "horse's" etc., so they likely have a electric fencer. It is illegal to cause radio interference. I would approach the camp owner(s) from a more benign perspective, e.g., "I'm trying to solve this mystery that only happens with my sonar on this lake." Its likely very fixable if its a electric fencer issue.
It's just a small bible camp on Lake Ellen. There's really not much in the area other than trees; no horses or fences, and the camp is on the opposite end of the lake. Like I said above, the DNR fish survey teams run into this on a number of area lakes and they believe it's caused by high-grade iron ore below the lake bed. (Magnetite gets its name because the iron content is so high that magnets stick to it. Because of the many near-surface iron deposits around these parts, compasses are pretty useless.)
Fr. K |
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Location: Mauston, Wisconsin | Sure its just a bible camp.....
http://www.lakeellencamp.com/lazy_e_ranch.html
There's a home on SE end that looks like it could have horses, e.g., using google Earth.
There's also a good chance its on private property...lots of horse lovers out there, even in the Yooper. Also electric dog fences, etc. I'm not a DNR fishery survey team member, so I wouldn't expect them to be experts in electromagnetic or radio frequency interference. Your sonar uses 50kHz to +200kHz. Depending on the settings and also depending on the harmonics involved, you are getting periodic pings from an interference source. Just for grins try a AM radio and see if you can hear the clicking. Just pretend you are in the Navy submarine service and the enemy's sonar is pinging you, your challenge is to identify the source and get rid of it!
You can easily see submerged steel structures with Humminbirds, its not a big lump of iron or copper ore. If it was, it wouldn't be periodic. Try changing the Bird transducer frequency settings also.
But, you may have stumbled into the Twilight Zone also, because your screenshot GPS coords put you on Lake Lenexa in Kansas. Did you see Toto too?
Have fun!
Al
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Location: Watersmeet, Michigan | I did not say that was my screenshot, but that I was getting returns like the one pictured. (I'm lucky if I can use 10% of the functions on the Humminbird, and screenshots ain't one of them!)
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| This is very interesting to me. Couple things - never seen an electric fence that pulses any less frequently than every 2 seconds, and why would iron deposits result in sound interferences in a timed manner? |
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Location: Mauston, Wisconsin | Padre, It sounds like its a electromagnetic interference issue. So, it can be a real challenge to identify without some research.. First, your Bird's - What model's do you have? I assume they work perfectly on other lakes. Do they individually work Ok, if the other is off on this lake?
Electromagnetic interference can propagate in some strange ways, including forming lobes that don't make sense to the average person, the interference may be weakest close to the source and increase as you are further away. I also noticed there's an small airport , but its a grass strip.
Lets try this: Using this link move the + cursor to the spot where the interference is the worst. Then click on permanent link and copy the address bar and post it in this thread.
Then do the same thing for where it disappears.
I have been thinking about heading up "North" to Presque Isle, its only a couple hours to Crystal Falls. I could hop in your boat and we could see if we can figure this mystery out....
Have fun!
Al |
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Location: Rhinelander, Wisconsin | Propagate.
Sorry Al, next time I see you I'll explain my weird mood today.
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Location: Watersmeet, Michigan | Al, thanks a lot, but Boat II has gone into winter storage. Snow is coming here Saturday and the gales of November have come early.
I will have to investigate next season. BTW, I have a 998c DI and a 998c SI.
Fr. K
Edited by Yooper Padre 10/15/2015 10:16 AM
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Location: Mauston, Wisconsin | Steve - LOL Way to funny! Bwaaaaaaaaaaaaa!
Padre, Lets get together in spring after the Michigan opener. In the mean time, I'm going to do some additional research & put together a plan & some test equipment.
Have fun!
Al |
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Location: Watersmeet, Michigan | Sounds like a plan Al. Thanks.
Fr. K
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