Numbers flashing and jumping all over the place - Help!

[Idaho-Marke]

We'll I got my F-75. Went and played some with it and then was busy for a few days.

One thing I really like. Batteries were included. Popped them in and guess what, nothing happened. Reset them once, then again and then the machine fired up. Not wild about the battery door. Looks like a water accident waiting to happen. Kind of thin and already once came undone and caused the machine not to start.

None the less, I really did appreciate the batteries from Fisher so I could go right out and play.

Once the machine fired up I went out back to my junk garden to play with the disc. On my MXT I just wave it over the trash and turn the disc until I lose the target I don't want. Not so with the F75. It lost it's mind and numbers started jumping all around. Had to reset it.

Are any of you able to wave the coil over trash and adjust the disc?

Before I did that however, I air tested some coins just laying on the surface. I couldn't pick them up more than 5-6 inches! My wifes wedding ring and a thick silver ring I found didn't do much better. I thought perhaps it was because I didn't GB. I did GB and still had a problem.

The DD coil is not the same as a whites. Pinpointing was difficult to start as was getting used to the large coil so I went to the playground to practice pinpointing.

Something weird was going on. When I sweep I get two beeps at the tip of my coil each direction instead of one???? I planted the coins under the surface and thought maybe it was bonus time, but when I recovered the target, the second beep was gone also. The two beeps was really weird.

Now, just tonight I only had a 1/2 hour or so so I went back out to my junk garden and chucked some coins out to learn how to use the larger coil in trash since I normally use a 4x6 shooter and still need to work on pinpointing. You know what? A quarter and a dime, laying flat on the surface would not give off a consistent number. It jumped all over the place and at times, from three inches away in a full sweep might even miss them both sitting amid the trash!!!! After trying it for a few times the numbers started spinning again and I had to reset it again.

Really like the nickels notch, but again I'm not getting a lock all the time with a nickel laying on the surface amid trash. I've got disc up to 60 with nickels notched in.

So I thought I had the sens up to high as I was running in default so I lowered it to 30 (BTW no static or noise at default 60). No change.

I did notice popping and some static as I increased the disc from default 10 to 60, but it really wasn't much of anything considering the MXT threshold.

ANOTHER NICE THING ABOUT THE F75. No threshold constantly. Perhaps in all metal (haven't gone there yet), but right now I'm enjoying the quiet.

Back to my concerns. Tonight in my junk garden with the coins layed out, not only did the machine NOT pick up the quarter, dime and nickle each and every time the coil went over them, but when I did a nice long sweep to get all three at once, I didn't get the signals (beep, beep, beep) each and every time. This is when I started to really get concerned as so many of you talk about the quick response.

When I tried to set different settings the numbers would start whirling and jumping around again and I had to reset a half dozen times before I gave up.

So friends. Any suggestions? MDing is not new to me, but maybe I'm missing some detail not in the manual you all know about that I don't.

I've had computers arrive DOA and thought this was one DOA F75 until it started after the third try, but I don't think something is right. I haven't really read about others having this problem of numbers jumping around without reason. Any Ideas?

Didn't get the pointer, rain covers or carry bag with the machine so that was a bit of a drag. Nothing in the box to tell me when to expect them or how to get them either.

The machine itself was packed well. Looks well made except the battery case. I'll feel better about the battery case with the rain cover on.

I'll look forward to your suggestions.

Thx

Mark

 

[jeff@middlesex]

Mark did you try different frequencies? You may consider trying another coil. I know your a experienced hunter but double check the coil connection going into the control box to be sure it is seated properly

 

[Mark in NC]

Idaho-marke,

Like Jeff said above, double check that coil connection... that can cause strange things for sure. The "double blip" type hit can happen on a DD coil when the target is very close to the coil (withing a inch or two). Try raising your coil as you sweep and you'll find it to turn into one target.

Let us know how the coil connection is, and we'll go from there! You've bought yourself an incredible detector, and when these issues are worked out, you'll love it.

hh'n

Mark in NC

 

[Charlie P. (NY)]

You did what I would do - lower the sensitivity. What sweep speed are you using? The F-75 works best when you really skim it along smartly - like a five foot sweep on under two seconds.

The double, even triple beep on very shallow targets is a DD coil phenonomen. Lift the coil 3" and sweep again when you get a series.

Pinpointing with a DD is also different. "X" the target, but shift yourself and the coil around so the center beam of the coil passes over the target perpendicularly. I wave it over a target and note a small feature (clover petal, blade of grass, etc.) that is over the beep and then sweep perpendicular. I can pinpoint to a 3" circle pretty regularly, sometimes better. A good mark is when I pop a 2" x 2" plug with four jabs of my Lesche and the coin comes out in the tip of the plug when I pull it.

What mode are you in? One of the things I like about the detector is that trash does make the TID hop all over while good items lock the TID pretty narrow. So far everything that hopped more than four units was trash when I dug it anyway (only way to learn). Bottle Cap mode accentuates this. And Jewelry make the machine very jittery.

The F-75 definately does not have a accept/reject feature like some. You kind of have to plan ahead. That's partly why I went to such trouble with the chart I made up. I set it up and then verify it in my test garden. I never did like notching things out because, I do believe, when you reject a target at, say, 43, you are actually rejecting 40 to 45. There goes a wide range of gold rings along with pulltabs. Once you have a typical tab you can adjust the notch using it if that one is a real problem feature at a site. I've found it easier to just sweep them and use the TID to rule them out as a target.

I leave the rain cover in the battery case. Mostly to keep dust out.

 

[Charlie P. (NY)]

Another thought. I wrap the coil cable tightly along the shaft. I've seen some who keep it very loose - to the point of slapping about. This is moving wire with electromagnetic waves moving within the search coil's field. You won't get away with that on a F-75 without causing false signals.

 

[AndyNM]

1. Start out with DE mode and keep the DISC setting between 5 and 19. Any lower or higher and the detector gets extra preamp gain power. That's why it can start getting unstable.

In english: At some locations you may not be able to run Disc lower than 5 or higher than 19 due to interference when the higher gain kicks in.

2. Make sure when you GB the detector that you DON'T see the words "can't GB" on the display. It is hard to see, but if you see the words "can't Gb" and still start detecting the detector has no depth.

3. Stay away from the JE mode the first hours with the F75. It is a very high gain mode and it is very sensitive to interference in this mode. If you start using the JE mode, start with very low sensitivity settings and work your way up when stable.

4. Make sure to turn off your cellphone...really off not stand by.

Andy,NM

 

[Texas TH'er "Georgetown"]

Just hold down the red button and push the pinpoint toggle forward and power on the unit. The F75 is a very sensitive computer. If you hunt in the city, you should always have another detector with you. There have been some tines in town while hunting yards that the detector goes crazy and I have to use another less sensitive detector. Freq. shift does not even help. But a reset sometimes will. I think it is wireless networks. Hope this helps...Dickie

 

[Idaho-Marke]

n/t

 

[Tagamet]

Isn't the "simple" explanation that this super quick machine is simply reacting the way it SHOULD when waved over a trash garden? I'm not trying to be smart, but multiple beeps and target ID's all over the place accurately reflects whats there. No?
Tagamet

 

[Charlie P. (NY)]

Can indeed. I set the sensitivity each use with the coil motionless and held just over the ground. Helps me fight off outside EMI.

 

[Texas TH'er "Georgetown"]

n/t

 

[Idaho-Marke]

n/t

 

[Charlie P. (NY)]

Once in the three weeks plus I've owned it?? What prompts you to reset?

I found the notches can get away from me because it stores the info in more detail than is displayed. I got in to try and clear them and had way more punched in than I thought I had.

Yesterday night I was searching around my shed and hit popcorn city. Sounded like someone dropped R2D2 down a flight of stairs. Couldn't figure what was going on. So I decided to trust the unit and dig around. Some years past someone must have set a can up and pepperred it with shot. I was finding hundreds if lead shotgun pellets scatterred around a six foot spot in two to three inches of depth. Also two brass grommets from an old canvas tent or tarp that read sweet, solid "34's", a 4" length of 3/8" copper pipe and a .22 WRM case. I had the discrimination at 6, no notch set and sensitifity at 88.

I also note that every time I pulled the coil back into a sapling or tough weed stalk it would "beep" with no TID displayed. Some of the bigger snags would give a false when hit, but the heel of the coil registered every hit even on the tiny snags. I was going to clean out my coil cover and see if this occurance can be repeated. Would make for a noisy hunt in some of the old home-sites I hit.

 

[Mark in NC]

Charlie, that one made me burn my sinuses with diet Dr. Pepper! On the resets, I've only reset a couple of times. Like you, it was to clear a bunch of notches (which aren't THAT hard to change manually, but reset is quicker)

I've not had any problems with the 75 cutting a fuss except one time, and it only lasted a few seconds. I attributed it to some type of temporary rfi blasting through. (I was in the middle of town, with two shortwave radio antennas in sight).. I didn't have to reset, it just quit on its own after about 5 to 10 seconds.