New Fisher F4 help. EMI problems? Something else?

[p1atypusx]

I received a Fisher F4 I purchased on eBay today. I went to bench test it and it went haywire. Figured EMI from inside so I went outside. Not any better but I was able to air test some coins and pull tabs. But when not reading it was still all over the spectrum. I don't think the EMI could be that bad, could it?

Here's a link to a one minute video showing what it's doing.



Is it just bad interference, or did I get a bad detector? The coil is connected well. Could it be bad coil? I turned sensitivity down and still bounces all over.

Any help please.
Thanks in advance.

 

Amazon Forum Fav 👍

Diving for Pleasure and Treasure - Grab it through Amazon!

[Hookedondetecting]

I would take it out to an area with no chance of EMI like a park. My units at home act goofy. First time I purchased one and turned it on in the house I thought someone sold me a dud. The back yard was not much better.
The Manual tells you how to deal with noise. Sensitivity, Ground Balancing and lowering Threshold help reduce noise levels. Some electronic hum is desirable.
Some say a cell phone signal can cause EMI.

Again go out to and empty area and try again.

 

[IBdiggin]

Wifi among other things can cause interference a populated areas. I noticed less interference when you pointed the coil skyward which could possibly indicate no problems with the power unit. Try running the cable straight up 6" from the coil to the shaft and secure at that point with electrical tape or a plastic tie before beginning to wind around the shaft. This is a common recommendation with the Garretts. I also did my F70 that way. I have noticed that same type interference at a park where I hunt near where some electrical installations went underground prior to crossing a creek.-Hope this helps---IB

 

[steve1357]

Wifi among other things can cause interference a populated areas. I noticed less interference when you pointed the coil skyward which could possibly indicate no problems with the power unit. Try running the cable straight up 6" from the coil to the shaft and secure at that point with electrical tape or a plastic tie before beginning to wind around the shaft. This is a common recommendation with the Garretts. I also did my F70 that way. I have noticed that same type interference at a park where I hunt near where some electrical installations went underground prior to crossing a creek.-Hope this helps---IB

Not that it matters, but the manual shows the cable wrapping in the opposite direction.

I have an F2 that doesn't like batteries when they start getting low, in the video it looks like the battery gauge is showing a notch or two low? Try two new batteries.

F4 manual direct from Fisher:
http://www.fisherlab.com/hobby/manuals/F4) REV 4 05.03.13 - Reader LR.pdf

I don't see the factory reset for the F4, but on the F2, when you turn it on, continue holding the power button down for 10 seconds. You won't see any indication that something happened.

Don't give up yet, and then there is always Fisher service.
Fisher Customer Service

 

[crazy4coins]

I received a Fisher F4 I purchased on eBay today. I went to bench test it and it went haywire. Figured EMI from inside so I went outside. Not any better but I was able to air test some coins and pull tabs. But when not reading it was still all over the spectrum. I don't think the EMI could be that bad, could it?

Here's a link to a one minute video showing what it's doing.

Video Link: Http://youtu.be/3wFfJ6_HCnM

Is it just bad interference, or did I get a bad detector? The coil is connected well. Could it be bad coil? I turned sensitivity down and still bounces all over.

Any help please.
Thanks in advance.

Definitely EMI, possibly an underground cable. I had the same problem with my F2 at one spot in my backyard.
Good luck!
C4C

 

[Sandman]

EMI for sure as if you had a broken solder joint it would false all the time. Check if a neighbor has a security system or electric dog fence.
Good luck.

 

[steve1357]

EMI for sure as if you had a broken solder joint it would false all the time. Check if a neighbor has a security system or electric dog fence.
Good luck.

found a dog fence EMI video...

 

[roaddust66]

go out into the country and see if its doing it. report back

 

[TheCaribbeanDigger]

As long as your near houses your going to get some EMI no matter where you are. When I got my first F2 day 1, I hunted my front lawn, but with tons of chattering. Like they said earlier. Go to some other place with no EMI.

 

[p1atypusx]

Thank you all for the advice. Took it to work with me and tested it at an old golf course and the interference was minimal. Unfortunately I haven't had the time I want to use it, but today I had to take pizzas to the kid's school, which gave me a chance to hit a small grassy area near a tree that kids and parents congregate. I only had ten minutes and didn't have proper recovery tools, but in that short amount of time recovered 41 cents. No silver but did get a copper penny and will definitely be going back.

Again thank you for your help.

 

[Hookedondetecting]

Great! Glad it is working

 

[Opie]

I would say you have the same problem I have at my house. You have a buried electric line for street lights along or threw your property. I only say this because you can see the light in your vid, and mine will do the same thing, loose the chatter as you lift it away from the ground. Blue stake came and tagged my yard, and I was amazed at the telephone, power and fiber optic cables in the ground in my front yard.