F75 sensitivity gain in relation to disc level

I've been away from the forum, and detecting too, for several years due to neck surgery. I remember, at least I think I remember, reading a thread here that explained how some disc settings on the F75 actually boosted sensitivity. I have looked for the thread over the past few days and can't find it. Does anyone have it bookmarked? If so, please post a link to it.

Thanks,
Chris

This is going from memory. Deepest depths accrued EMI allowing in order 0,1,2,3, and 4 levels of disc
And higher sensitivity the better in these disc settings-- again EMI allowing

Now disc levels 5-20 are reduced depth disc settings, at level 21 you get a lot of depth back

Disc levels 6 and 7 can be used for hunting in heavy iron using monotone-- will be somewhat depth limited, listen for more whole sounding tones -- pops and crackles will be iron, iron bits, and nails.

Disc setting supersedes sensitivity setting for the deepest depths detecting

They do work with each other though for overall results.

I am assuming here you are running one of the original units ( non DST) with or without boost.



Edited 2 time(s). Last edit at 03/22/2016 07:08PM by tnsharpshooter.

Good memory...and not to be too critical.....I believe you're off by one number though, lol. I think it's 20 and above in disc that kicks it into a higher gain.

I've not noticed any 'step' changes in sensitivity, that would be poor design, if it occured. But there is a definite 'step' in electrical interference pickup going from Disc=5 to Disc=4 in DE mode.
Previous threads here: (sadly my ImageshackUS link no longer works - they started charging for their free hosting????)
[www.dankowskidetectors.com]
[www.dankowskidetectors.com]

I must try some alternative image hosting sites, see if I can restore these threads.



Edited 1 time(s). Last edit at 03/22/2016 08:00PM by Pimento.

Thanks for the info TNSS. As I read your post I had one of those "you knew that" moments, funny how the memory works.
I was running an original camo ltd until last month when I sent it in for the upgrade. Is there a difference between the ltd and ltd2 when it comes to disc vs. sens?

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
"I am an engineer. My job involves explaining things to idiots. Then the idiots make bad decisions based on misinterpreting what I said. Then it is my job to try to fix the massive problems caused by the bad decisions. Eventually, rumors overwhelm facts and I give up. In the final phase I assign blame to an unpopular coworker. So whatever you do in life, don't be unpopular."

If you have been away for a few years you may not have heard about the upgrade Fisher is offering on F75s/LTDs/SEs to DST technology which reduces or sometimes can eliminate chatter from EMI. Imagine being able to run Sens 99 and Disc 0 without much or any chatter. The upgrade expires at the end of this month. Link below:

[www.fisherlab.com]

Also, I believe NASA-Tom said that with the upgraded or new F75s with DST the difference in boosts at the Discs levels you asked about is less pronounced.

Edit: Oops, just saw your reply where you had already sent it for the upgrade. This is one of those days when I should have stayed in bed.



Edited 1 time(s). Last edit at 03/22/2016 09:27PM by DFinTX.

NASA-Tom wrote: "It is more difficult to see any form of pronounced depth/performance/gain whilst Disc is 4, 3, 2, 1 or 0......... and the subsequent Disc of 20 and above. It still exists; yet, is more subdued."

That was in regards to the prototype DST model I believe, not sure if it carried over into production models. Here is the link: [www.dankowskidetectors.com]

No need for the oops, your comment about Tom's statement regarding the difference not being so drastic on the updated units was a vital piece of information.Thanks for the link!



Edited 1 time(s). Last edit at 03/22/2016 10:11PM by Neugene.

Neugene Wrote:
-------------------------------------------------------
> Thanks for the info TNSS. As I read your post I
> had one of those "you knew that" moments, funny
> how the memory works.
> I was running an original camo ltd until last
> month when I sent it in for the upgrade. Is there
> a difference between the ltd and ltd2 when it
> comes to disc vs. sens?


Since you are running upgraded unit.

You will have a new fast audio FA process

The detector definitely quieter than the older.
On paper--- in an EMI free environment,, a small bit of depth is sacrificed vs the older.

Bp process--- operator will notice recovery speed is slower vs the older.
And here the coil AIR gap distance is diminished using Bp process with updated vs the older.

In many rural settings I have been able to run my unit at 99 sens, 0 disc-- with little or no noise.



Edited 1 time(s). Last edit at 03/22/2016 10:30PM by tnsharpshooter.