Fisher F5 with 13inch Ultimate FIRST IMPRESSIONS

They are not good. Oh, here at home this combo, with wide open gain and threshold will air test a dime at 14 inches!!!! A quarter at 16 inches. I mean, with a good repeatable signal!! I ground balanced the machine and sit it on the ground to achieve these results. This was last nite, here at my home....in the yard. BUT TODAY.....
I head out to my first old home, still standing and the yard is still kept up. I flip on the unit. WHAT HAPPENED TO MY NICE QUIET F5???? It went away. There was a steady loud clicking. I ground balanced the unit. 48. Two bars or iron indicating low iron content (i reckon, who knows?). I then started backing off the threshold with gain wide open. Even at -9 Threshold, clicking is almost justa s loud. I start backing off the Gain. I made it down to 80 and it quietened down. I went ahead and air tested it just to see how much the lowering of those controls affected sensitivity. It dropped my air testing results to almost a quarter of last nites results. I'd have been better off carrying the Deus.
My objective was deep untouched coins. And after last nites mind-blowing air testing, i figured that I would be reaching deep today. I took it to three of my different old coin spots. Same thing, except one was worse. I had to use -9 Threshold and 50 Gain. I also tried it the other way around on these yards. I turned threshold to zero. Then, I could only get the gain to 30 before the sound got unbearable. So...I was wrong. I though that i had me a deep silver getter. Maybe out in the country......but around here everyone out in the country was poor.
These leads me to a question: What is the deepest unit on silver where EMI is an issue???? A NasaTom calibrated CZ-3D???
I am going to take the Ultimate coil off and put the 11 inch DD coil back on and see if it helps. I mean, those big coils are just big antenaes arent they? I must admit that the Ultimate coil, and all of my other units, save the F75SE runs quietly around my house. I have never had as loud a unit as I had an hour ago. This will never work. Must go to plan B. I just don';t have a Plan B.

Heh Kevin, Sorry to hear that. When I got the Ultimate coil on my G2 I found it didn't stop me froming running my gain all the way up like with the 11", but it did make one place I hunt that has power lines running across it mostly unhuntable within 50 feet of the lines, whereas the 11" had no issues there. I also noticed that my ground balance will be about 10-20 numbers lower with the Ultimate than the 11" in the same ground. Also when I airtested the Ultimate coil to the 11" there was NO depthy difference....but in the ground I have a proven 2" depth increase. It sucks to hear that because I was considering picking up another Omega and would have liked to use the Ultimate on it, but being that the F5 and Omega are "mostly" the same machine...guess that won't work. Bill

Hi Kevin,
Sounds like you ran into 60 cycle interference like something from an electric fence.

Did you try different frequencies to see if one calmed it down any? Did you try the motion setup? Did you try to see where the interference was coming from and moving away from it or seeing if you could have it turned off?

Remember the two stability points? One with the coil held still and one with the coil in motion? It sounds to me from reading your report that you only set up for the stationary point. Did you try setting up the detector with the coil in motion over the ground?

There are two stability points on the F5. There is a stability point with the coil held stationary (not moving). You adjust the gain and threshold until it gets to chattering and then you back off one or the other or both until its quiet or mostly quiet. Then you go swing.

Then there is another stability point available to you with the coil in motion. You sweep the coil continously over the ground and adjust your gain and threshold until you find the settings that you like for that. The F5 uses the ground signal to help suppress EMI and will let you obtain higher settings than you could with the coil held still.

Before you chunk it, try another site armed with some more knowledge.

HH
Mike

Mike, I will try to answer those questions: First, the EMI (constant clicking) was the same at all thre of my old coin sites. They are within a mile of each other. I DID look for electric fencing but saw none. Just old homes. Now.....those old homes may have had burglar alarms. But in the last big empty yard that I went to, there are no homes that look like they would need a burglar alarm.
I did notice that when I put the coil to the ground it would silence a bit, but teh steady rythym was still present although not as pronounced.
I took the 11 inch coil back and was able to run the machine with full gain and -6. That was getting a bit better. I have a strong feeling that the good coins are way deep and was counting on that Ultimate coil to reach down deep.
Oh...one thing....I noticed that when I had the big coil on and it was laying flat on the ground while I was digging, it had that loud steady rythym to the point where I had to jerk my headphones off as it was driving me crazy. I was reminded of why I got rid of the Omega. But the Omega even did it past 70 here at my house. The F5 is quiet here. I will try a few more places where 8 khz will be helpful before I do something drastic. I surely do appreciate the feedback.

Sent you a PM Kevin.

Mike Hillis Wrote:
-------------------------------------------------------
> Hi Kevin,
> Sounds like you ran into 60 cycle interference
> like something from an electric fence.
>
> Did you try different frequencies to see if one
> calmed it down any? Did you try the motion
> setup? Did you try to see where the interference
> was coming from and moving away from it or seeing
> if you could have it turned off?
>
> Remember the two stability points? One with the
> coil held still and one with the coil in motion?
> It sounds to me from reading your report that you
> only set up for the stationary point. Did you
> try setting up the detector with the coil in
> motion over the ground?
>
> There are two stability points on the F5. There
> is a stability point with the coil held stationary
> (not moving). You adjust the gain and threshold
> until it gets to chattering and then you back off
> one or the other or both until its quiet or mostly
> quiet. Then you go swing.
>
> Then there is another stability point available to
> you with the coil in motion. You sweep the coil
> continously over the ground and adjust your gain
> and threshold until you find the settings that you
> like for that. The F5 uses the ground signal to
> help suppress EMI and will let you obtain higher
> settings than you could with the coil held still.
>
> Before you chunk it, try another site armed with
> some more knowledge.
>
> HH
> Mike

Mike I DI notice that the unit got quieter (like the Omega I had a few months ago) when I started swinging with coil to ground. I never thought of adjusting for EMI while in motion. Will try today. Thanks for that feedback. That is some good usable info-mation.

Kevin, the F5 was my primary detector for over two years. I enjoyed the F5 and made many good finds with it.

Mike Hillis was and is the undisputed master of the F5, there is very little I can add except to put an exclamation point on what he already said about adjusting the gain and threshold settings with the coil in motion.

In most locations, the F5 can be run without interference WAYYYYYYY hotter swinging over the ground than stationary.

It definitely got me in the habit of removing headphones during retrieval.

Having an overactive detector myself, the mute switch on the headphones like the Grey Ghost Ultimates, is a mind saver.

I can run my Gold Bug wide open most of the time with the 13 inch coil with just a little chatter.
Not enough to lower Sens but not quiet like the stock coil,

Yes I agree with the recent replies and with Mike H.'s recommendation. I have been using the F5 alot as, in my soil, and with the 11 inch DD coil, I get about as much depth on coins and other stuff as I get with any detector I've had. And that's in DISC mode. When in All Metal (Autotune) mode, I can penetrate much deeper!!! But I really have no use for all metal mode in the majority of places I hunt, so the F5 in Disc Mode serves me well. I NEED a detector with this low frequency and the F5 does just fine. I will admit, in my home test, the XP Deus will penetrate through the ground and hit coins at an inch deeper. But I have yet to run head to head with these two detectors on a real world deep coin. I have kept the F5 longer than I thought I would, because it is no slouch (with 11 inch DD coil) where decent depth on coins is concerned). Old buttons too. And it hits my 7 and 8 inch Minie Ball bullets with repeatable signals in DISC mode. It gives a iffy signal on the 9 inch bullet. And a faint hint of an iron tone on the 12 inch bullet. But in All Metal, with threshold at zero, it hits everything that I have buried with a diggable change in threshold. (If I was hunting at or near a battlefield site in woods and field.)
Thanks for the relies guys.