Field test for the F70

[diggin4relics]

Has anyone done a full blown field test on the F70 yet? I will say one thing, it does like picking up objects on edge. I dug a small dog tag this morning at 5 inches deep and it was straight up and down in the ground. I think it ID'ed at about 55. It was brass. I gave it to the guy that let me look in his yard. I was there talking to him to find out where the Battle Of Blues Pond took place. They say soldiers were lined up on one side 700 yards wide. This took place in 1864. I will get to look there after the corn crop is out of there.
The F70 was a little chattery, sens was at 70, threshold was at 0. Next time I'll reduce the sens and the threshold.

Mike

 

[tony (Orlando FL)]

Mike,

I noticed the 'on-edge' ability of the F70 also on several coins I have found over the last few days. There was no doubt that there was a good target under the coil at some very impressive depths.

I have been running mine at Sens of 20 or less and getting outstanding results with the threshold at 0. If the area isnt loaded with trash, I can go to near max sens with an occasional chirp. In really trashed sites, I have run mine as low as Sens = 10 and done great.

 

[patricka]

Asking for help from other F70 users. I recently purchased one of these machines and although I realize I need to practice and experiment with it more, I have having two issues - it being chatty and I am not seeing the great depth others are reporting getting. Trying to figure what I am doing wrong and I just saw the two previous posts for the first time now, but here has been my experience over the last few days. Just recently got the machine. Took it to a local park here in Chicago. Pretty much kept it at the factory settings for in Program 1 except I turned up the discrimination up to about 57 given how trashy the park probably was. I had not detected this park before It ran very very chatty almost to the point of being very frustrating. Tried to reduce the sensitivity to about 40 but still was chatty. Constant erratic short blips registering in the 80s and 90s on the ID but with no confidence or confidence of 1 bar and then disappearing indicating a false signal. Correct signals for coins did register and I did find about 30 clad coins in an hour and a half. All were in 2 to 3 inches of the surface. Did find a two wheat cents at 3 inches and one at about 4 inches. Was hard to search given the chattiness though.

I then returned to my dad's house in northwest Illinois today and tried to do some further testing. Had rained alot in the past few days including this morning and ground was nice and moist. Was still chatty in his yard and in 3 other locations we went to - an athletic field, a park and a yard of another house. Typical Midwestern soil with no unusual mineralization nor was I near powelines or underground cables. I decided to do some depth tests with some old coins he had at his house. Pretty much started at factory settings and started with a Barber dime and cut a 5 inch plug, put in the dime laying flat and put the plug back. On factory settings with discrimination at 50, it jumped around between 54 and 60 with 1 to 2 bars of confidence. Thought would be better. Could not get a signal at about 8 inches even at discrimination of only 20. I then replaced the Barber dime with a silver Washington quarter. Got a good constant signal in the 70s to 80s laying flat but when I put the quarter at a complete vertical in the dirt at the 5 inch depth, could not get a decent signal with or without and discrimination. Running in all tone was useless. Would detect the coins but was way too chatty to use. Same results for a wheat penny as with the dime. Went to a local park and also to an athletic field and could not get any targets greater then 3 inches in discrimination of 55 other then large pieces of aluminum cans. Did find several clad coins within a few inches but machine was still very chatty to the point of not wanting to use it.

Final destination was an old 1850s large brick house that my father had obtained permission to hunt. It had never been hunted before! Spent about an hour there. Ran it with factory settings but adjusted discrimination to 20 and sensitivity to 40. Still extremely chatty to the point of frustration. Did find targets at up to 6 inches but would expect to find more deeper items at a house that old. Coins included a 1910 wheatie, a 1936 Buffalo nickel, 2 1950s Jeffersons and 2 memorial cents. All coins were in the 3 to 5 inch range but the machine was so chatty it was real hard to use. Other targets included pieces of lead, a brass shotgun shell bottom, a pull tab, medium size pieces of steel, etc.

I need to practice some more but I would think it should run in the factory settings with decent performance.

Any thoughts, tips, or even jokes would be appreciated. HELP!

I would love to know what the benchmarks of this machine are, i.e. at

 

[tony (Orlando FL)]

When I first got mine too, it seemed to be wild and erratic as you state.

A long story made short here.

I reduced the sens to 15 and it became nice and solid. From there I increased and decreased till it behaved nicely.

Then I went home and did some air test comparisons on the sens settings and found sens settings as low as 10 provide a lot of depth.

Yesterday I used the F70 at a setting of 10 most of the day and found several deep coins. The fella I was with was using the F75 and his sens was near MAX. My experience is that the F70, for whatever reason can not be used at high sens #s if there is metal trash all over the place.

In clean areas, I was able to run MAX with a few chirps here and there but clean areas are rare in my detecting grounds.

FWIW, there is another fella here in N Florida who also was experiencing the erratic behavior on his f70 as I was and the same as you describe. He felt his unit was defective until he also reduced his sens wayyyyyy down.

Whenever I start to detect a new area with the F70, I start between sens 10 - 20 tops, and adjust accordingly from there.

The sensitivity control might should be called / renamed to 'stability' control. I have tried various threshold settings even a max of -9, yet sensitivity made the biggest improvement.

I dont think this is a problem, just a learning curve we all have to go through. Learning our detecting grounds and detector. The F70 is VERY sensitive as you have already found out.

I hope this helps some.

BTW at a sens setting of 10, I was still able to detect coins easily into the 8-9 inch range. Probably deeper as I could raise the coil a few inches and still hear the target, but there werent any deeper that I crossed over at the time (that I know of anyways)

Give it a go and dont be concerned about low settings.

Tony

 

[jackintexas]

As I have stated before it is sort of like driving your Ford or Chevy every day for a long time and then one day you get a Nasa race car to drive to work. You would not drive the race car as you did the Ford Or Chevy. The F75 and F70 detectors or not like other detectors you have used. Most want to use the sensitivity at a very high setting as they did their other detector. When you can hunt a site far way from mainly electrical interferrence you will find you can open it up.They are so sensitive you must set them depending on the site you are hunting. They are unusually deep at low sensitivity settings.....Jack

 

[jmaryt]

thanks for the info tony!..very helpful!....have to remember that!

(h.h!)
j.t.

 

[hsjrev]

I've found that this machine is very dependant on a good ground balance too. It's very important to set the disc to 0 or AT initially and find a spot free of metal to get a good fast grab on the dirt. When I seem to be having any depth issues, it's usually time to do another ground balance.

 

[patricka]

Thanks for everyone's input. I really appreciate it. I will get a chance this weekend to get out and try reducing the sensitivity and do more testing to see how it handles in field conditions and at various depths. Did an air test tonight on my dining room table at sensitivity of 20, discrimination at 16 and threshold at 0 and could detect coins of different sizes 5 to 6 inches away with strong signals and 3 to 4 bars of confidence. Once I got out at 7 to 8 inches could not get a signal. Will report back Sunday night.