Base threshold

[Rob (IL)]

I'm working on some programs and need an explanation of Base threshold. Most of the programs are at 90 but the high pro is 65.

Base threshold - By adjusting the degree or %, Spectrograph can be adjusted or calibrated to preference.

So what does changing it do to the Spectrograph? Rob

 

[ak_1234]

A base threshold of 90 will show the top 10% of the highest bar along with any of the other bars within that signal strength range. A base threshold of 65 will show the top 35% of the highest bar...

 

[Larry (IL)]

It sounds like you are digging pretty deep into the Expert menu Rob.......... Good for you. I'll have to have you help me with some program designs...

 

[Rob (IL)]

Thanks AK. Sure Larry like I could help you. I've got questions when I see you. Rob

 

[ak_1234]

Here's a little more if it's of help...

Using the same example (a base threshold of 90 = 10% signal showing, a base threshold of 65 = 35% of signal showing). If you have a base threshold set to 90, it will go off the strongest signal and display the top 10% of that signal as well as signals that are >90% of the strongest signal. Any deep targets that are less than 90% of the strongest signal will not be displayed on the spectragraph. However for a setting of 65, the deeper targets need to be only >65% of the strongest signal to show on the spectragraph. So, if you don't want to see as much of the surrounding noise, you increase the base threshold. To catch the deeper targets relative to your strongest signal, lower your base threshold.

 

[cvs]

IF I follow what your saying then would it make since that it could or would help if you lowered the threshold as your coil size gets small and raise it if the coil size is larger.

 

[Larry (IL)]

Is the audio linked to the VDI display? In other words, if the Base Threshold is 90% will there be less noise in the audio as well as the VDI? If I understand your explanation, with the higher Base Threshold, one may lose the VDI and maybe the audio on the deepest of the targets.....?

 

[Rob (IL)]

Bob, (rcsnake) uses the 65 in his Hi Pro program. Since he wrote the Hi Pro, maybe he will jump in on this one. Rob

 

[ak_1234]

Is the audio linked to the VDI display? In other words, if the Base Threshold is 90% will there be less noise in the audio as well as the VDI? If I understand your explanation, with the higher Base Threshold, one may lose the VDI and maybe the audio on the deepest of the targets.....?

No, it is strictly a spectragraph screen resolution setting. You get to tell the screen how much of the signal you wish to see. Has no effect on anything else in the system.

 

[ak_1234]

IF I follow what your saying then would it make since that it could or would help if you lowered the threshold as your coil size gets small and raise it if the coil size is larger.

If the smaller coil is less susceptible to noise, then that is true. You don't want to have settings such that external noise overwhelms the good signals. We don't have knowledge of the future, so we're adjusting on the fly. So, the bars on the screen are adjusted based on the current strong signals. If you set the base threshold too low, then you are setting up the detector to show more noise which will make a good signal not stand out as much (only for the spectragraph - no effect on any other part of the detector). If you don't have noise, then this is a good thing. So, really it's a setting that you can adjust based on how much of the smaller signals you want to see. Most programs were set up to not run very hot (well, hotter than the DFX, but still not as hot as hi-Pro or a couple others).. Bob set his up to run fairly hot and that means he also wants to see more data. The newcomer might get overwhelmed by all that data, so it was set higher.

 

[Larry (IL)]

Thanks Anne, you're the greatest................

 

[rcsnake]

Bob, (rcsnake) uses the 65 in his Hi Pro program. Since he wrote the Hi Pro, maybe he will jump in on this one. Rob

The Base Threshold set to 65 in the Intensity section on the Search Display setting under Spectragraph is set to a setting where in my ground it still showed good responses on non-iron target, however on targets such as bottle caps I would bet a little more of a smear pattern on the Spectragraph. I have found this to be very dependent on the ground and the brand of the bottle cap. Besides, it just seemed like a good place for that setting as I like to see as much data as possible without being overwhelmed by the graph smearing on the targets that are in question and still have a decent pattern on acceptable targets that I want to dig.

Bob@Whites

 

[Larry (IL)]

You did a great job putting that program together Bob. It was a piece of cake using the V3 Hi Pro from coming from the DFX that was cranked to the max.