Digital Shielding Technology (DST) scored a very nice find.

[Mike Hillis]

Hi Liaso,

I can't tell you how the new one compares to the old one regarding depth. But I can give my max air test results so that you can compare......
inside the house, 99 sens, disc at 15, audio mode on 3, max distance a high tone is repeatedly received.....

A dime will air test at around 12.5" to 13" in BP mode.
A dime will air test at around 11" to 11.5" in DE mode.

DST doesn't affect the test results in any significant way. DST

Hope that helps to answer the question.

HH
Mike

 

[liaso]

Thanks Mike

HH
Liaso

 

[basstrackerman]

De mode on my f70 was same exact results Good to know

 

[cometguy]

Wow, this sounds like Christmas to me. I have long ago gotten used to the unique pops and cracks of EMI but there are times you get sick of hearing it. I am sure we will think our machines are broken if the EMI vanishes. This is a dream come true for the F75 users.

Don
HH

 

[basstrackerman]

I hope i have some good hunting weather after my new f75 gets here!! I am wondering if i should sell the f70 or trade for a g2 or omega 8000... Just to have a diff frequency machine

 

[cometguy]

Bill, I love my G2. It really does what it says it does. Great in iron. Very simple to set up and use. I don't think you would ever regret it if you are a field and iron hunter.

Don
HH

 

[Cal_Cobra]

Interesting that it looks like Dave and the Fisher team ARE listening to our critisims of the F75 (EMI is a big one), as we see new features implemented to resolve those issues. The variable LED lighting with the ability to disable it on the F19, and now the DST on the F75 which was pleagued with EMI issues IMHO.

I have the F75 LTD and it was quite problematic with EMI. At one point it had a non-EMI problem that I discussed with Dave J. and he asked me to send it back to FT so they could replace the motherboard and coil. After that change its been very stable in EMI, and I do a lot of city hunting around the San Francisco bay area which is inundated with EMI issues. Typically I'm able to run the machine from 80-99 sensitivity in places I previously could not prior to the motherboard swap. Makes me wonder if they did anything aside from just a new motherboard, and if it would benefit further from the DST software upgrade?

Wish FT could add the F19 lighting option to the F75 too

 

[ronhob]

Have you read the manual? It states just the opposite for turning the DST on and off.
The way I read it, DST is off in 9.1 and on in 9.0

D.S.T. (DIGITAL SHIELDING TECHNOLOGY)
Traditional detector technology requires users to "work into the noise" at high gain settings to
achieve maximum possible depth. The F75's latest technological advance,
Digital Shielding Technology (DST®), permits the use of maximum sensitivity settings with
minimum background noise. This noise reduction reduces user fatigue and enhances the
detecting experience.
The user may choose to operate with DST or without DST.
The default setting, at power-on, employs DST
To turn DST OFF, perform the following:
1. Turn detector off.
2. Press-and-hold the grey MENU button and
push-forward-and-hold the TOGGLE SWITCH.
3. Turn the detector on, while you are still holding the controls.
4. Continue to hold the controls.
5. See the "90" displayed.
6. Rotate SETTINGS KNOB clockwise.
7. See "91" displayed.
8. Release the MENU button and TOGGLE SWITCH.
Upon release of the controls, the detector will operate WITHOUT DST
DST status is saved to memory after the user performs this procedure.
Each time the detector is powered back on, it will continue in the programmed setting.
The same procedure is used to turn DST back on, except that the SETTING KNOB is turned
counterclockwise to change "91" to "90".
DST can be turned on or off as desired, but each change requires the user to first power the
detector off.

 

[lytle78]

I believe that that is just one of the very many typos in the manual. I believe 9.1 is DST.

 

[adespin]

In what situation would you want to turn off DST. I can't see the reasoning in keeping version 9 on the machine.

 

[Mike Hillis]

That is a good question,Adespin.

DST is the name giving to an additional filtering process. In basic terms, DST is applying a new threshold level that a signal must overcome for the detector to respond to it. Its probably more complicated than that as I believe there to be some sort of internal reference signal in use, but either way, simple or complex, this threshold level will affect performance on the smallest signals because the detector can not tell the difference between electrical interference or a metal object. Because of this it should be used only as it is required.

In the past, the first line of defense against EMI was frequency shifting, followed by reduced sensitivity settings, or some form of discrimination.

Now, the first line of defense against EMI is still frequency shifting, followed by activation of DST (with frequency shifting), and lastly, reduced sensitivity levels or some form of discrimination settings.

HH
Mike

 

[basstrackerman]

So it could be like the F70 using threshold to lower emi issues.. I made a video a while back using the F70 on an 8" deep quarter with sens at 1 and thresh at 9 was able to pick up the quarter.. Lowering threshold i lost the quarter at a threshold of 0... So i know on the F70 it does effect depth.. There are plenty of places i can hunt with sensativity at 99 and threshold at 9 if i chose to hunt that way with F70 .. But i hunt alot with machine 100% silent and sometimes that is threshold -1 or -2 and still find lots of very deep coins and buttons..

 

[detectingMO]

probably more like a signal signature like cancelling/threshold vs straight line thus minimal performance impact