Having a hard time getting my F75 stable

[digitrich]

I'm using it in a plowed field that has telephone poles running down one side, which is probably giving electrical interference, doesn't seem to bother my SE though. I can't get the F75 to quiet down until I turn down the sensitivity down to about 38-40, and my tones are extremely short, scratchy and very high pitched. Is there a setting to make the tones longer or smoother? I probably have the settings whacked. I have it on 4 tone because there is shield nickels where I'm at, plowed fields, 0 discrimination, notch 1 because I don't know how to make it 0, and if I auto GB it comes in about 50, about the same manual GB. I just wish I could get the tones more solid and get it more stable, not so chatty, can't seem to get it to lock on to anything. Again, this may be specific to this site, I have yet to try it at another, but I need it to work at this site so I can send my SE for repairs and still work this site while I'm waiting. Any advice?

 

[Charlie P. (NY)]

If you are running zero discrimination why not switch to Motion All Metal? It runs quieter and is more sensitive. Then you can lower the tones, also. (Range is -9 to +9).

Turn off any cell-phone (not just "standby") and see if another frequency calms it.

 

[Tagamet]

[quote digitrich]I'm using it in a plowed field that has telephone poles running down one side, which is probably giving electrical interference, doesn't seem to bother my SE though. I can't get the F75 to quiet down until I turn down the sensitivity down to about 38-40, and my tones are extremely short, scratchy and very high pitched. Is there a setting to make the tones longer or smoother? I probably have the settings whacked. I have it on 4 tone because there is shield nickels where I'm at, plowed fields, 0 discrimination, notch 1 because I don't know how to make it 0, and if I auto GB it comes in about 50, about the same manual GB. I just wish I could get the tones more solid and get it more stable, not so chatty, can't seem to get it to lock on to anything. Again, this may be specific to this site, I have yet to try it at another, but I need it to work at this site so I can send my SE for repairs and still work this site while I'm waiting. Any advice?[/quote]

JMHO (and I'm no expert), but it MAY be that you are GBing over a piece of metal. The "Can't gb" lettering is really tiny to my old eyes. If you're not GB'd right it'll act exactly as you describe (been there, done that). If it were me, I'd: reset the machine to the default mode. Then I'd either use autograb to balance it (and watch for the can't gb message) OR not GB it at all (I've been told that the default gb is pretty good). Then I'd reduce the descrim to 5 or 6 to rule out a lot (if not all) of the iron. The default sensitivity should be fine, but if it's still chattery, walk it downward. Also, I'd change the frequency to one of the nine alternative settings (HOLD the red button and push forward or pull back the trigger to adjust it up or down one notch. You have to release and repress the red button and the trigger to get another frequency. My machine acted exactly like yours and the problem seemed to be running descrim way too high. By reducing it to 6 and using DE and delta pitch tones, I'm doing pretty well hearing everything that's down there. I do also like the 3H or 4H tones (this machine is a Nickelodian), but I've been searching for a child's lost ring at a soccer field and need to dig everything THERE anyway.
In broad brush strokes, Good GBing,changing frequencies, lowering the descrim setting, even using modest sensitivity levels, makes the F75 a very stable, quiet machine that's still plenty deep and quicker than a split lip.
Hope this helps and keep us posted,
Tagamet

 

[wallyblackburn]

Again, not an expert (just got mine Tuesday), but it appears that another stage of amplification (pre-amp maybe?)is kicked in when Disc is set below 5 or above 19 (maybe 20). IMHO, it changes the whole personality of the machine.

Haven't tried Motion All-Metal as another suggested - if that does not include the pre-amp, it sounds like a good idea. I'm pretty sure the pre-amp is in at all settings in Je mode.

Like you, I have to tuen Sens down <40 whenever pre-amp is "engaged". But I can run 85-90 without it. Tones also become "smoother" and less "scratchy".

Have Fun!
Wally

Worms Fear Me...

 

[duggr]

Try it with the tones set to 1 tone and see if it becomes more stable. Don't go below 30 on the sensitivity or the detector will become erratic! Try setting threshold for all metal at zero. Set Your Discrimination at 5 or above,sometimes when I go below 5 it will become chattery.I never run high discrimination so I don't no about the Higher gain past 20 on the Disc setting.I had the same trouble in a plowed field when I first got the F75,but havent been back to that area since to try out my settings...Don't be afraid to set the sensitivity low on the F75 when you need to.

 

[AndyNM]

Go here : F75 FAQ number 8

and look at Question number 6 and 8.

Andy,NM