General Detecting Post./ First Texas Information

[Cal_Cobra]

Hi Bill

No I didn't see that chart you did. If I didn't I don't remember.

It was Ralph at SunRay in a conversation I had with him lately that brought it to the front of my mind. He had discovered it when first developing his probe for the F75. He had phoned Fisher, and had spoke to both John & Dave about it. Fishers work around was to set the default, notching out the lower segment of the discriminating range.

Yes, it has caused a lot of problems. We'll compound it with the fact they had a batch of flunky coils in the beginning that just added to the mysterious, (perceived to some degree), electrical interference problem. Lets not forget about user error.

The coil thing is behind them. Users should do a little reading, educating themselves about the lower discriminating thing. If they operate the F75 with a tad bit of common sense, they will discover it's a good unit. Now I'm not trying to say the F75 is going to fit every ones need, and your not never going to have any bad moments with it, but overall it's a good unit.

Bill are you stating that to get the "boost" mode with a disc of 4 or less, you can just disc out iron with a disc of zero and get the max depth?

I recall reading NasaTom's report of this "boost" mode with a disc of 4 or less on the F75 on his site.

Brian

 

[Mr.Bill]

It's almost time for the crops to come in - what settings should I use?

I use factory mode to start with, (DE) with single tone, default disc., sens. 90+, and a good ground balance. Yes it's noisy, but one can easily tell good targets from bad. Most the low end iron comes in with crappy tone, a lot of spitting & popping for the foil, tabs, etc., brass, lead, coins, real clear sharp tone. Try it, it's not as crazy as it seems.

 

[Mr.Bill]

Tom is correct. Lift the notch off the discrimination. The unit most likely will become unstable. I guess your accustom to that.

 

[Canewrap]

Everything you said is why I dumped an F75 for an X-terra 70 and I couldn't be happier. I too, don't buy into the I don't understand the machine argument. I work in computers and aerospace and if its electronic I can figure it out.

 

[markg]

Where is the sensitivity on this graph?

Mr. Bill,

Has that boo boo been corrected?

I don't know if you recall when someone, not me, mapped the Disc vs Sensitivity and posted a nice graph.

[attachment 139474 F75Discrim.gif]

Long ago(~2 years) when I saw the graph I made a post stating that there was something wrong with that code. Of course with 20+ years of developing microprocessor based products I'm just an idiot & don't know squat. Certain individuals got their panties all in a knot. But the end result was that the boo boo has caused all sorts of problems for end users and soured many on the F75. It has hurt their sales, but this was completely self inflicted and foreseeable + correctable.

So have they taken the time to correct it? If they have it may actually be a more stable detector than the original F75.

HH
BarnacleBill

 

[gmanlight]

To get the spec on that graph of 7.5 inches with a disc of 6 i have to
drop my sens to 60 . If i raise the sens to 80 or above im at 9 + inches
HH Mike