Questions on F75 ltd...

Hey guys! Been a long while since I've signed in on here. New job, a 3 year old boy & other responsibilities have made hunting the past year or so almost non-existent

With some newfound time on my hands, I'm getting ready to hit the dirt again hard. I have a Tom tuned 1021 3d which is unbelievable!!! I broke the faceplate last season & never had a chance to send it in to Fisher. Will do so within the next week or so. In the meantime, I just scored the find of a lifetime a few weeks ago. I was looking around a pawn shop in my town & came across a like new F75 ltd. for sale. The owner had it in the store for quite a while and was eager to sell. Said he'd never buy another metal detector again, lol. I scored it for $300!!!

As I'm getting ready to pound a few sites with this baby soon, here's my questions...

1. I've read several different ways to run with this beast on this forum. I think I remember Tom saying that there's a depth boost if the discrim is set at 4 - or maybe it was 4 and lower. True? Also, I've seen many folks say that they run their units "balls to the walls" wide open with 0 discrim & sensitivity at 99. Isn't this a bit much on such a hot machine to begin with?

2. I rarely hunt in a "bed of nails" type spot. However, most of my spots DO have at least some iron mixed in with the rest of the normal trash. Think moderately trashy. I'm primarily a coin shooter who digs the mid tones looking for the gold as well. Mostly older parks, woods, etc. what would be the best settings for this type of scenario? I would strongly like to hear the iron under my coil. At least even a slight chirp or crackle so I know it's under my loop. So any settings that will allow for this is what I'm seeking.

3. I have at least a few upcoming hunts scheduled with minelab owners. I've heard horror stories about the M.L.'s making the F75 go nuts from interference. Is this just dramatics or over-exaggeration, or, will I have a difficult time hunting? Further, do I need to change frequencies or do the operators of the M.L.'s need to do it?

4. I really LOVE that nickels ring up high tone on my CZ, so I'll probably run with the 3h setting to have the same luxury. However, is it easier - or better - to hunt in 2 tone mode instead? Any tone option you guys recommend would be terrific.

Appreciate all your help in advance! Good to be back

Joe



Edited 1 time(s). Last edit at 03/03/2013 03:01AM by njnydigger.

I swing both with many months on an e-trac and just a few weeks on the F75 but not at the same time so I can't speculate on the interference but the 75 is a definite EMI magnet. If you're hunting coins and expect to follow the iron with your threshold think again , unless you're hunting in all metal -- no threshold on discrimination side. I'm definitely a newbie with the 75 but I'm guessing not many are shooting coins in parks running it "balls to the wall", at least not successfully. The factory default of disc at 15 and sensitivity at 60 may seem tame but is a good starting point until you learn the notch sequences.

If you're a tone hunter you're in for a real disappointment. In terms of tunes , the e-trac is Celine Dion while the 75 is Janis Joplin.

Quote:"I think I remember Tom saying that there's a depth boost if the discrim is set at 4 - or maybe it was 4 and lower. True?"
This thread may explain the disc / sensitivity behaviour:
[www.dankowskidetectors.com]

Joe,

Time permitting..... you may want to read the thread titled: Rcpt Ack of F75 LTD Proto. It's only a few pages down.
Also.... if you are a coin hunter, I would strongly recommend using 4H tone option (instead of 3H).

Always make sure your coil jack is REAL finger tight, especially if your having problems w EMI.

I rarely ever have been able to run the sensitivity wide open, especially in the city.

Hey Joe, welcome back. I think you'll like the 75. You got a heck of a deal on it.

Thanks for the thread links guys! VERY useful info I came across which I saved & will transfer onto a "cheat sheet" & bring to the field with me All of the below is EXACTLY the type of instruction I was seeking.

(Glad you loved the video. Another one is 'in the making'. As far as maximizing your F75 at a site that has been hit hard...... the principle is still the same. IF IF you can set Disc at '0', 4-tone, Sens '99' and hit it hard.....this is your best bet. If EMI is an issue....start by doing a Freq change with F1 thru F7. Find the freq that provides the least EMI. THEN.....if EMI is still a problem..... try raising Disc up to '4'. If EMI is still an issue....raise Disc to '5'. Then to Disc '6' if required. And with Disc '6'.....if EMI is still an issue...start lowering Sens. Try NOT to do any of these things.....if possible. It is good to have 'some' EMI. Then place coil on the ground and start sweeping. Quite a bit of EMI will 'go away'. PUSH YOUR LIMITS!!!)

(DE/PF/JE modes are for highly trashy areas.
BP mode is for fairly trashy areas.
CL mode is for moderate/low trash areas.)

(THE BEST WAY TO REDUCE EMI: Place F75 in all-metal mode with max Sens ('99'). Hold coil about a foot above the ground.....very still......and perfectly parallel with the ground. Select F1 through F7.........one at a time...... and listen to each channel/freq for about 4-5 seconds. Find the one freq/channel that provides the least interference. Now you can switch back over to the ID mode......and.....yes......this Freq/channel selection will stay the same whilst switching over to the ID mode. If you are running the unit 'wide open'....and you still are encountering EMI..... you can change Disc to a setting of '5'. There is a huge difference between Disc '4'....and Disc '5'. You should not have to increase Disc to higher numbers. If EMI is still present.... you now can start to drop Sens .... until EMI is gone. Remember; you are already on the best possible F1 through F7 Freq/channel selection...and must employ other methods so as to reduce EMI... if it is still present.)

Still have a few more questions though...

1. As most of my sites are of the moderate trash type, seems I will be utilizing BP mode most of the time. However, as one who normally lightly scrubs the coil against the turf, will I be nulling the advantages of using BP mode? In other words, do I actually need to raise the loop and use the air gap to see beneficial results, or, can I still scrub the soil?

2. Any advantages/disadvantages in doing a fast grab to GB the unit versus manually GB'ing? Or are both methods accurate when working in the BP/JE/CL/PF modes?

3. Are most of you guys running in BP mode with the little 5" round coil or the stock coil for moderately trashy parks & woods hunting for coins & jewelry? I know Tom stressed the importance of knowing when to use each weapon.

4. I really enjoy & get more info with modulated audio response from targets. I like to know when I have a deepie. Tom recommended hunting in 4 tone mode. Curious as to why? Does 4 tone offer any type of modulated audio? I remember reading it does not.

Your thoughts & advice is considered golden & greatly appreciated!!!

(THE BEST WAY TO REDUCE EMI: Place F75 in all-metal mode with max Sens ('99'). Hold coil about a foot above the ground.....very still......and perfectly parallel with the ground. Select F1 through F7.........one at a time...... and listen to each channel/freq for about 4-5 seconds. Find the one freq/channel that provides the least interference. Now you can switch back over to the ID mode......and.....yes......this Freq/channel selection will stay the same whilst switching over to the ID mode. If you are running the unit 'wide open'....and you still are encountering EMI..... you can change Disc to a setting of '5'. There is a huge difference between Disc '4'....and Disc '5'. You should not have to increase Disc to higher numbers. If EMI is still present.... you now can start to drop Sens .... until EMI is gone. Remember; you are already on the best possible F1 through F7 Freq/channel selection...and must employ other methods so as to reduce EMI... if it is still present.)

What if after this procedure you have had to increase discrimination past 50 and reduce sensitivty to below 40 and EMI continues to make sweeping anything but a chatterbox after GB and changing to the 5" coil?

Tom or anyone else with F75/F75 ltd. experience care to elaborate on the questions in the post 2 above this one? Thanks!

i hunt exclusively with the 5" coil in trashy parks! i generally run in '2" mode
and get "modulated audio" on deep hits.run around 75 to 80 sensitivity,disc set at "6"
in urban environments with very little interference from (e.m.i.) i' getting 7" to 8 " on a dime
since i hunt this way most of the time,i seldom use the 11" coil anymore.

j.t.

jmaryt Wrote:
-------------------------------------------------------
> i hunt exclusively with the 5" coil in trashy
> parks! i generally run in '2" mode
> and get "modulated audio" on deep hits.run around
> 75 to 80 sensitivity,disc set at "6"
> in urban environments with very little
> interference from (e.m.i.) i' getting 7" to 8 " on
> a dime
> since i hunt this way most of the time,i seldom
> use the 11" coil anymore.
>
> j.t.

Thanks for sharing J.T.!!! Yes, I too would prefer to hunt in 2 tone, however, a LOT of folks recommended 3H instead - which is fine since nickels come in as high tone & the modulated audio is available in that mode - then Tom advised 4H instead. Guess I'll have to try all three modes now, lol. Hopefully Tom will chime in and explain why 4H is more advantageous. Seems like a great set-up J.T. I also hunt fairly urban sites. Not smack dab in the center of the town square or city, but within the general vicinity & was a bit nervous about all the EMI horror stories I've been hearing. Thanks for clearing my mind a bit! Anyone else???

Came across a great vid on YouTube by the Norfolk Wolf showing the F75's performance on coins located near iron. Awesome!!! Haven't had a chance to get a long hunt in yet with the 75 but boy am I itching to lol. Hope Tom doesn't mind me posting a link to the video...

[m.youtube.com]



Edited 1 time(s). Last edit at 03/04/2013 06:27AM by njnydigger.

I use "FastGrab" exclusively on the F75. It's more than sufficient in moderately mineralized soil where I usually hunt. I've never needed to manually GB as I do with my CZs..

There's a big difference in 3-tones vs 4-tones on the T2/F70/F75 platform. When you are in 4-tone........ many older coins will report as the 3rd highest tone. If you are in 3-tone........ all of these coins will ID as a mid-tone........................ just like aluminum trash. Whilst in 4-tones...... and hunting for coins and old-coins........ dig the top two tones. Sometimes the 3rd highest tone (whilst in 4-tone) is called the 'zinc penny' tone. Yes.... zinc pennies do audibly ID as the 3rd highest tone.......... but so do silver Trimes, Half Dimes, Indian Head pennies, $5 Half Eagle gold coins, silver coins slightly masked, early generation wheat pennies......... and a host of other coins. Any of the tone option settings does indeed give modulated audio responses...... as long as Sens is approx '80' or below.

You will most probably (and highly recommended) find yourself hunting in 'bp' mode all of the time. You may need to adjust Sens/Disc/F1-F7 accordingly .... to mitigate EMI.... as per recommendations in the thread titled: Rcpt Ack of F75 LTD Proto.

If EMI is excessively severe......... check the tightness of the coil connector on the back of the control head. If EMI still remains too severe....... you may need to detect with a different unit............ but, verify ....by going to a different location.... that EMI is not 'maximum severe' anywhere/everywhere you go. In other words.............. if EMI is severe everywhere you go (including a trip into the country)......with moderate settings (say: Sens 50, Disc 10, 'bp' mode and proper F1 - F7 selection) ... you may have something wrong with your unit.

For Grnd Balancing...... Fast Grab is quite accurate...... assuming the dirt you use to Grnd Bal with is clear of metallic objects. You may want to manual-check the 'Fast Grab' method a few times. Chances are....... you will enhance your confidence in Fast Grab.

((( This thread should have been continued in the Rcpt Ack of F75 LTD Proto thread......... to maintain consolidation ))).

Don't forget to try the "CL" mode with sensitivity set between 10-20. Set a minimum disc for your environment, add delta-pitch and you've got a formidable, unique detector!

Fisher engineered this unit to be able to be driven into an unstable condition in most conditions. They should have provided a password to unlock sensitivities >75, only attainable through a written test after the unit logged a minimum of 100 hours use!

go-rebels Wrote:
-------------------------------------------------------
> Don't forget to try the "CL" mode with sensitivity
> set between 10-20. Set a minimum disc for your
> environment, add delta-pitch and you've got a
> formidable, unique detector!
>
> Fisher engineered this unit to be able to be
> driven into an unstable condition in most
> conditions. They should have provided a password
> to unlock sensitivities >75, only attainable
> through a written test after the unit logged a
> minimum of 100 hours use!

Lol! Funny Go-Rebels!!! I'd probably fail the test though I have run with a Safari before (great unit, didn't fit my style though), a Tom tuned CZ 1021 model (by far the deepest & best unit I ever owned) & a Teknetics Omega 8000 ( which was a super machine but fell short in the depth department.) So, I do have a feel for how the Fisher/Tek family of detectors operates. However, I know the F75 is an entirely different beast altogether, lol. I am new to "delta pitch" rebels. Care to enlighten me on its specific functions, as well as the pluses & minuses of using it? I didn't even know the F75 ltd. had a delta pitch setting. Gracias!



Edited 1 time(s). Last edit at 03/04/2013 02:00PM by njnydigger.