F-70 Threshold question please answer quick

[michaelnc]

Hey guys and gals,

I just sold my F-70 and the guy I sold it to said it has a problem with the threshold sound. I honestly can't remember ever having a solid threshold background while hunting. I thought on the F series detectors that the threshold only increased the size of the signal not giving you a constant smooth sound compared to say a Whites machine. Am I correct or is it supposed to give a background noise while you hunt.

Thanks,

Shane

 

[wayne_etc]

In AT (autotune or zero discrim) you'll hear background hum. In Discrim you won't.



w

 

[cometguy]

Remember that you can raise and lower the threshold also.

 

[wayne_etc]

Yes
From page 16 of the manual (For Autotune Mode):
"At 9, you will hear the loudest background sound. At -9, you will have the lowest possible level of background sound."
From page 17 of the manual (For Discrim Mode):
"Adjustable from -9 to 9. 9=accepts the smallest size targets. The detector may be noisy at this setting.
-9 = The maximum amount of elimination of small targets. The detector will operate quietest at the -9 setting.

The manual is here: http://www.kellycodetectors.com/pdf/manuals/f70.pdf


w

 

[michaelnc]

Thanks for the info. I'm sending the customer an e-mail to let him know about gain (sensitivity) plus threshold setups to help find a threshold hum in AT or zero disc setting.

Thanks,

Shane

 

[osgood]

was the f70 not your style of machine? Just wondering.

 

[michaelnc]

I actually liked the F-70 quite a bit. However I prefer the CZ-70 Pro as its built like a tank and a much quieter machine. I don't think its any deeper and it may be masked by iron but the F-70 responds faster than you can think and that'll give you a headache after a while cause it sees every little piece of metal in the ground. For the money the CZ series are some of the best coin shooters ever made. They are deep on silver and copper and built to last plus I've had one CZ or the other for the last 12 years..

Shane

 

[wayne_etc]

Oh Yeah! The CZ70 is one of my all time favorites. I miss the one I had. I even had that big whoopin 12'' sunray coil on it. And you're absolutely right about the F70 hitting on everything. You'll find goodies with the F70, but you might have to tuck some Tylenol in your gear bag.


w

 

[Leo234]

One quick note on background hum. I know we are talking about the F-70 but since the F-75 and F-70 are close relatives I thought I would share a recent experience. Several weeks ago I was in an area free of EMI and found myself able to crank up the F-75's sensitivity above 95 which is rare in a suburban America. With the sensitivity cranked, I started noticing a threshold hum in the background forcing me to take a close look at the F-75 settings to verify everything was set accordingly. Sure enough, everything was correct. Just out of curiosity I dropped the sensitivity below 90 and the background hum disappeared. When I increased the sensitivity back to its original "overdrive" setting the threshold hum returned. I have read that there are others who have also experienced the background hum when running the F's with maxed or nearly-maxed sensitivity settings.

Leo

 

[gates21]

I have never heard any threshold on my f-70. I usually run it at -3 to +3 depending on site conditions/emi