I finally get out again Friday with my F75 LTD.. I had some problems....

[jbow]

In a nutshell... I could not get it to quieten down in disc using BP, I did not try any other modes however, when I wouldswitch over to AM it would become really stable and quiet at the same sensitivity. I could hunt quietly, except for the hit every few inches, in AM. When I switched to AM I found a spot and did a fastgrab. I switched back to disc and tried 4tone, 2F, and 1 tone with the sens set the sam and lowered to 50. It was chattering like the original did in JE with the sens turned high. I was trying to hunt in 0 disc since it was quiet in AM. It would quiten down just a little bit if I raised the disc to 6 but it was still very noisy. I was using the 11" stock coil. It would quiten a little bit when I lowered the coil to the ground and started to swing. I tried all the different frequencies, a coiuple were werse but none seemed to be better.
I hunted this site many times with an original F75 and had no problem with it, same with the T2, no problems.

Why would it be queit in AM and noisy in disc?

Julien

 

[tvr]

Ground thawed enough yesterday to go digging in open areas that get full day of sun. One of those areas is where I've had interference issues with the LTD. I don't have your experience with the F75 to draw on and compare results to. I did not try all metal so don't know if I would get the same results you got. Will have to do so on another outing to this same area. Different frequencies did not help. Discrimination up to 16 did not help (did not go higher than 16).

What did quiet it down was dropping the sensitivity down to 9 to10. I hunted running 0 disc. Played with tones 2F, 3 and 4H. Tones, frequency, discrimination did not make a lot of difference but dropping the sensitivity until it stopped chattering worked. It still chattered a lot at sensitivity of 12; started to quiet down at 11 and got very quiet at 9 / 10 settings. I was then able to hunt the area near this noisy transformer and get coins down to about 6 inches. That's about as deep as I find coins in this play ground area when I am well away from the transformer. I found a short piece of copper pipe and the bottom of a corroded tin can both at about 8 inches.
tvr

 

[jbow]

I'll try dropping the sens until it stops. It is just goes against everything I have learned but if you're getting coins at 6" with the sens under 10 I bet it will go a little deeper.

The first time I went out with it I was hunting a place called Brushy mountain, it is known for being hard to hunt because of the bad mineralization. The place I was hunting was 15 to 10 ft away from underground utilities and a couple of hundred ft from hing tension power lines. I was using the small coil with the sens on 99 and disc on 0. It was so quiet I had to keep checking to make sure it was on. I was even able to hunt the gravel road that GA Power uses to service the powerlines... I didn't try the 11" coil there. I will when I get down there again and i'll try the small coil at the place I went on Firday...

J

 

[tvr]

Julien,
Kind of wonder if a power line is starting to develop a fault either underground or in an overhead high tension insulator. Many years ago I worked for a place that made power fault detection equipment. There were corona test sets to see if insulators were starting to break down and there were the "thumpers" that would basically dump a high voltage charge from a capacitor bank down the buried lines. With some of the low cost units, the utility workers would walk the line and listen to where they heard the thump (where the short was). Higher end units measured the return wave and told you how far down the line the fault was. Power lines can be real quite and then get real noisy when something starts to break down. Things can generally run degraded (noisy) for a long time before there is a big loss of transmission efficiency or a loss of service that makes the repairs get done.

I should add that the ground in the place I had to drop the sensitivity to 9 to 10 is pretty easy hunting. Ground balance is 60 to 62 and the Fe3O4 reads mostly 0.03 but occasionally would see a 0.1; so it is not hard to go deep under those ground conditions. In red clay country, you probably have a much bigger challenge.
Good luck to you.
tvr
PS It is raining cats and dogs today. I hope to get back out tomorrow though. I will have to try all metal.

 

[jbow]

I don't think that is the case, my other detectors all run just fine there as did the original F75. I will try the small coil and take the T2 when I go back either tomorrow or Tuesday so I can compare. IIRC, the FE reading was is in the .3 range there., high but not too high. Loads of old iron and ore, pieces of cut surare nails and can slaw.
FWIW, after trying the LTD for a while I got out the ET and found a fresh dropped nickle and a whole cartridge, either a Spencer or a Burnside, i'm not sure which. It is in two pieces but almost all there. The part with the bullet was at about 7" and the base of the cartridge was at about 9". I've hunted this place for several years and have pulled loads of CW stuff out of it. If I can take keeping an eye on the display AM with the LTD might really be productive at this place.

J

 

[woodchiphustler]

Mine goes dead quite with this setup. BP mode ,2 tones, disc 7 to 9 sensitivity between 70 to 80 in ground I hunt. If there is an electrical fence nearby you will have a hard time. Try different freq.

 

[jbow]

Tried 'em all, i've hunted this property for years with all kinds of detectors including an F75. It was very quiet in AM... I don't get it but i'll keep fiddlin' with it.

J

 

[Tinfoil]

n/t

 

[tvr]

Just back from going back to test the interference.
In discriminate mode running BP: discriminate level, different frequencies, different tones would not quiet it down until the sensitivity was down to 9.

Switched to All Metal motion and it was dead quiet until sensitivity got to 45, then I'd hear a few faint zips. At 50 there were more frequent faint zips and at 60 the zips started to get louder and frequent enough to start making hunting tiring for me. In all metal motion, even up to 55 sensitivity it was very usable. Higher and things started to get very chatty with non-repeatable sounding off.

So, my LTD kind of sounds like it is similar to Julien's experience with the interference. The other detectors I have can hunt this location with high sensitivity settings with out sounding off on the interference. The LTD set at sensitivity of 9 still finds things well and I'm digging targets here at least as deep as I've dug with the other detectors. Over all I end up with a higher coin count on the play ground with the LTD than I do in comparable time with the other detectors; seems to be the on edge coin advantage.
tvr

 

[jbow]

That is encouraging.. I think.

I will try dropping the sens to below 10 if need be... that just goes against everything i've ever learned though.

BTW, I was hunting in motion AM, I never hunt in static AM mode unless I am in a very clean place where I might find deep artillary shells.

I wonder why AM is so much quieter. I am sorta glad that if one is quiet, it is AM because you can really clean a place out by using AM and watching the numbers. That is one reason I have so many machines. I find that different machines will find different targets at any given site. Like in heavy iron the Tejon with the small coil is deadly, the T2 is almost as good, the Tejon is just much quieter... it seems to just ignore the iron alltogether. In mineralized soil the E-TRAC is better, IMO. First passes at a site, Sovereign and/or V3... finally to clean up, (if you have a good site and unlimited time)... the F75 in AM, one small patch at a time. Then start all over after a good rain...

Thanks for the input!

I will be out at that some place tomorrow.

J

 

[jbow]

Both my T2 and my original F75 had to go back to FT. The T2 twice. The second time it came back rock solid and much more stable than my 75 ever was. It is a really good and stable machine now. I will probably send the LTD in soon, I want to try a different 11" coil on it first.

FT products taught me to keep the inner and outer box whenever I buy a detector. One thing though, even though I had to send them in... they still worked before I sent then in and even better once I got them back.

A funny story: My T2 is an early one. I got it direct from FT in a group buy for the G$&S hunt a few years ago when it first came out and we were considered the Bounty Hunter team. So... I got is a few months before the hunt and used it every day so I would learn it. I had read about it being a chatterbox so I was prepared for it. Man... it was noisy, but I was still making finds... but after a couple of weeks it really started to get to me. I called FT from the field because I was beginning to think something was wrong, it was getting worse. The tech got on the phone and the first thing he said was "check and see if the coil cable is tightened where it connects to the control box"... I touched it and it went crazy. I tightened it and it went quiet...
After those two weeks, I could hunt with any machine! Laff. It impressed me that I made a steady stream of good relic finds even with the cable loose.

The T2 and the F75 are both awesome machines, I just have to get this LTD figured out. I have a buddy with one and he says his is so noisy he cannot hunt with it. He took it to the Ft. Donelson hunt and could not use it. He used his original there last year with no problem. I don't think he tried lowering the sensitivity to below ten... and even if that works, it doesn't sound right.

Time will tell I guess.

J

 

[Tinfoil]

If you put the threshold to a -2 or -3 you will only lose about 1/2" detection depth but you can run a higher sen. in all metal. The Threshold has nothing to do with Dis. If you run the threshold up in all metal it will get a little noisy com-paired to a -2 or a -3. In all metal a 0 threshold and a +9 ( more noise)you will get a couple of inches more depth. You just have to play around with it.

Now adjusting the freq.

I find in a real noisy area F6 runs my F75 much quieter in all metal and Dis. then the rest of the freq.s but, it just all depends on the type of noise you are in which freq. you are going to use.. You have to play around. I have not had my LTD up high in the Dis. about 80 is the most I run at 0 Dis. When I hit the noise I play around with the freq. first, threshold second (if in all metal), Dis, the then sen. Most of the time I do like I said run both machines at min. of 80 and 70 sen. I have thousands of hours on my F75 and like I said my LTD runs even quieter then the F75. I hunt the iron and trash so I do have to run it lower in sen. like mostly at 70 even then it gets about 2 more "s of depth then my F75.

The LTD is just a plain bad news bear for the on edge targets. I really think that is due to the wider footprint that the LTD puts out on the coils com-paired to the F75 Footprint on the same coils. The fisher 101/2" coil is a good example of finding on edge targets. However you have to be care full of the high sen. you run on the LTD when you are in the trash and iron due to the size of the footprint. I run at a lower sen on the LTD then my F75. I have really started to like the 2F tone in the trash and the iron.

Anyway just some thought for you. Listen when My F75 don't act right it gets sent to First Texas to get fixed. Hell, that is what the Warranty is for and I use the hell out of it. I am not going to have a whimpy detector that acts stupid. It is some hard hunting down here and if you aren't digging 8+"s you might as well go home as you are not going to find anything old. That is how deep the old coins are in the ground matrix here.

Now that is not even talking about my beach hunting. Now when you get into salt water black sand beach hunting now it is a different ballgame and you do have to do different things to make the F75 hunt and to get the same depth that you get dirt hunting. I just crack up and at the guys that say the F75 is not very good at the beach. That is a prime example of not knowing the machine. OK I am back to my normal Lurking and reading and hunting. Send that machine in it is broke. Later Bud, : : HH Jerry aka Tinfoil

 

[Cal_Cobra]

The disc between 5 & 21 is a reduced sensitivity setting in BP & CL modes, and will usually quite the machine down if the ground is the cause of the noise, but if it's EMI all bets are off.

 

[jbow]

Yeah, it was slightly quieter with the disc on 6 but nothing like with my original F75, and all my other machines work well there. I haven't been able to get back over there yet but I have my T2 in the truck too. That should tell me something... if it runs quiet set hot, the F75 should run quiet. I am going to to try the 75 in DE too so i'll know if it is just the BP mode, I don't think it is though. I am wondering if it is the 11" coil because i've been able to run it with the sens on 99 and the disc on 0 at another site using the small coil and it was so quiet I had to check to see if it was on.
So, I am going to try both DE with the 11" and try BP with the small coil. I hope I can get over there today before the rains sets in.

Running the sens below 10 in BP mode just doesn't seem like the right answer... maybe it is though. I'll post more later, I hope.

Thanks for the help!

Julien

 

[Daniel Tn]

I sold my trusty original F-75 and picked up the LTD F-75. I always ran my F-75 at 90 sensitivity and motion all metal mode and never had a bit of trouble out of it, unless I was around a pulse machine or something. Everything I read about the LTD at the time, said it should be the same as the F-75, and some were even saying it was quieter. That's what I was expecting.

Instead, the LTD I got you couldn't put above 30 sensitivity, in ANY mode, or it would go absolutely crazy. I thought that was just the nature of the beast, and kicked myself for ever letting go of that original F-75. I traded the LTD for a pulse machine, and hot off the press news...just got my old F-75 back from the guy that bought it from me. It will be here Friday and it will never leave me again. But anyway, I read on the forums where some guys with the LTDs love them to death and swear they are quieter than their original F-75s, and then I read of folks that had the same experience as you are having and that I had...and I really don't know what to think. Most people seem to think mine had a bad coil....which I think you said you hunted an area with the 5" coil and it worked great. Maybe that IS a sign of a bad stock coil on yours too. I wish I would have thought of checking that out on my LTD, but all I knew was that the LTD I had wasn't anything like the old F-75 that I had, and I was pretty hot about spending that much $$ on a machine and it not being right from the factory. I've had a lot of good machines from Fisher over the years, but they are also the only company in which I have EVER gotten defective machines. But they are always pushing the edge on technology and I'll keep buying as long as they keep producing winners.

 

[tvr]

I can go about 4 to 5 higher on the sensitivity with either the 6.5 elliptical or the 5 inch DD coil than I can with the 11" DD. So, no significantly large difference in where I can run with the different coils with respect to noise in the headset. Re-reading a number of posts with folks able to run sensitivities in the 80 to 90 range and run quiet ... I will call First Texas and see about sending it back. I have found no place where I can run quiet in disc mode and get sensitivity higher than the 50's. At 60 and up it starts becoming all pops and zips that are not repeatable.
tvr

 

[jbow]

I tried it again today. De mode was better than BP but not as stable as the original I had. In Bp I could run the sens on 20 with the disc on 6 and it was usable but not quiet. My T2 was just fine with the sens on 75 and the disc on either 10 or 21. I didn't try the small coil on either machine today but I shouldn't have to.
I had to send my T2 in twice and my original F75 in once to get them right. I wonder... they must just slap the parts together and turn it on to see if it beeps and ship it out.

At least it isn't my only detector... I think I am going to have to send my V3 in too. Today it was acting up, the screen was flickering, it said that the WHP weren't working but they were and the audio was sorta fuzzy. The pinpoint started sounding like an Explorer with a whole bunch of tones on everything I tried to pinpoint... I am going to try a master reset on it topmorrow... at least the E-TRAC and the Sovereign always work.

Julien

 

[boxofchocolates]

I never had the orginal f75 can't compare them.....my ltd was sounding off also turned the sen. to 4 dis 7 all was quite....air tested good but haven't used it lately.....hh....dan

 

[kered]

If it was dismounted for cleaning after the last hunt make sure the coil wire is real tight, i and others have had problems with this, although mine is the normal F75, its amazing what thet extra less than 1/4 turn will do

 

[boxofchocolates]

Here is another thought guys.....I recently discovered when I switched to swing right handed the housing was near coins in my pocket causing the jumping chattering affect...ltd very sensitive at the housing area...hh...Dan