first day out with the f-75

finally got out with my baby,and went to a 350 year old common.set it up with disc at 6. gain at factory,and 4 tones. gb was 75.i was able to push gain to 85,and left it there!..only had a very short while to hunt,and only dug one target a gum wrapper @ 5"..pinpointed dead nuts on and depth WAS acurate!..detector was "dead" silent.the common was ringed with high voltage power lines but it appeared that 'emi" was not a problem..didn't find anything else,but before i stopped i changed the process to (j.e),and things went on full chatter!..backed gain down and it didn't help,so got out of j.e,and went back to (d.e)..for some reason i could NOT get the detecor to quiet down in de process either!..didn't have any time left so went home!..at the time the detector went batty on d.e i noticed it was around 6:00 (p.m)..i am thinking maybe there was a surge of voltage thru the power lines that produced the "emi" because of the time of day?..maybe usage was higher,and THAT caused the detector to act up?.i turned down the gain again in the de process mode and again it did NOT work!..still chattery!..any advice?..thanks!.i did NOT attempt to change the frequency as i had to leave and ran out of time!

j.t.

Set Sens to around '40'..... then turn the detector off. Wait a minute...... then turn the detector on again..... THEN SLOWLY bring the Sens up. Yes .... the 'JE' mode will do exactly what you experienced.... in most places.

tom!
i will try that and thank you for the input!..does this also happen with any attempt to change to all metal mode too?..i was also advised to perform a"reset" and this also should work!..let me be more clear on what i was doing!..i was hunting along just fine with the detector set to disc @ 6 gain @ 80,and (de) process...detector was running sweet,and absolutely stable..I DECIDED to change process to (j.e) just to determine IF this site would allow me to do it!.when i realized it wasn't happening,i attempted to revert back to (d.e) and experienced the difficulty,which caught me off guard,as i wasn't expecting the detector to react that way!..is this a 'glitch" in the written software?..thanks again for the tip!

j.t.

My guess is you'll see the same MIS-behavior if you increase your disc above 15 for more than 10 minutes. I still stand by that something is wrong with quality control at Fisher. Mine went back today for service. The only way, I'm able to recover from these fits of tones (and it's not EMI chatter - it's the system cycling through all tones and numbers - you can see a pattern to it if you watch it for a minute or two) is a factory reset then I have to put the disc at 6 and the notch at 1. I can go all the way to 90 sens, but can't touch other settings. Then I'm good for about 1.5 hours before the next reset is required. Of course using those settings in any place other than a corn field will drive you absolutely nuts.

I explained this similiarly in another post. Of course, it was explained away as my inability to operate this "superior and complicated, 4-setting" :sarcasm: detector.

[www.dankowskidetectors.com]



Edited 2 time(s). Last edit at 09/03/2008 01:44AM by Shambler.

Thanks heavens this is being discussed. I thought I was the only one that got two bad machines in a row, the way this machine is being talked up on a couple of different forums. I got rid of the second one I had because I didn't want to spend forever trying to get it to work if it was just an inheritantly bad design. That EMI problem, inaccurate depth reading on everything with the stock coil and the build quality of the LCD screen is why I gave up on the F75. I have an F70 and I'm going to do a full assessment on it in the next couple of months, since my initial use of it in the beginning of summer was fairly positive. As a lightweight find a relic site, type of machine it may be just the ticket.

John,

I can not quite 'pin down' a reason as to why the F-75 acts in such a fashion. Yes, there are times that a reset to factory presets can clear a problem. Sometimes , simply turning the unit off...... waiting a few moments...... and powering it back up on MUCH lower settings.... (then increasing settings slowly) may also cure the problem.

Keep in mind..... there may still be some areas where EMI is severe.... and no matter what you do to the F-75....... it may never be able to hunt a particular site.

tom!
i am NOT being critical in any way!..i want to establish that!..i will get out again on friday at the same site and will try what you instructed me to do,and i feel it is a minor issue that hopefully will be ok!...i am positive you know what needs to be done,and once again my thanks for the sensible tip!..i will attempt to do both procedures and i have faith one or the other WILL work!.if not,then i will just move to a new site and continue to learn the detector!..i have confidence in it's ability to do what it was designed to do,and i will not give up on it.to reiterate,i DON'T feel it is a big deal,and look forward to many pleasurable outings with it!..what happened took me completely by surprise so i was looking for experienced opinions,and hopefully some advice!..i got both!..i am happy!..thankyou!

j.t.

Not a problem... Let us know how it works!

due to time constraints,doesn't look like i will get out there again until monday!hope to "hit" this site hard,as it was the first place the settlers lived in 1635!.it is a wide open common,and my stategy is to get as much depth as the 75 will give me in any mode so i can thoroughly hunt it!i will do my best to make sure i am able to hunt this place as i have a good feeling there may be 'deep" coin,as well as "tilted" coin there!.will advise on the "chatter" issue!..thanks!

j.t.

With THAT old of an area......... I recommend digging ALL mid-tones that are deeper than 4".

excellent point!..well taken!..what i find especially appealing is the fact the area HAS been "beaten" to death by just about everyone,and EVERY detector known to man from late seventies onward to the present day!.i want to really work it thoroughly with the latest technology.(f-75)to attempt to determine just how "good" this detector is!..the terrain is perfectly flat,and is quite a large area to cover!..i KNOW there is something there,and the 75 is the "tool" of choice!i will know what i am up against if i can find a "deep" "good" "hit"
anywhere on the site!.