RX Sensitivity and Probe

[jgedde]

My v1.0 Vision was replaced due to some bad issues with the wireless headphones - not the usual audio glitching others have reported. I got my replacement unit today: a Spectra V3 with v1.1 of the code.

On the Vision with v1.0, the probe feature seemed to give me reasonable estimates of RX sensitivity (i.e. 7-10, sometimes as low as 3-5). The new unit almost always shows 15 as the recommended sensitivity - even in some instances with TX Boost tuned on. This is in multiple locations, including locations I've already hunted with the Vision. I have to back it down from the recommended value to get the detector to become stable but in some cases was able to use 15, but the "trust" factor just isn't there anymore. Use of the probe feature became standard operating procedure for me when starting a hunt with the original unit.

I have two questions:
1) What is the "normal" range others are seeing with the probe feature (I realize there's a lot of variables)
2) Was there any change to the RX probe functionality between v1.0 and v1.1?

Apart from that, the replacement detector seems to work normally and has already yielded some coins from their entrapment despite only having the replacement unit for a few hours.

The Vision/Spectra V3 is amazing. I've found more coins in the past three weeks than I found in 5 years with a ! Good job White's! Between the phenominal detector and customer service, they've got a customer for life! It just doesn't get any better!

Cheers,
John

 

[tab-nabit]

I have the Vision v1.0 and the probe feature seems to always want to give a high recommended Rx setting - usually 15

 

[cx3]

In my location High Point N.C. my probe reads 11 to 13 every time I have tried it. Im not sure if the V3 has DC Phase like the XLT and the DFX had but my ground would read -92 on those two detectors which is suppose to be fairly hot ground I am surprised that I can run such a high RX and not git a lot of chatter on the V3.

Jerry Murphy

 

[cvs]

I have a Vision (not Spectra logo) but with V1.1 and in the front yard the probe always gives me around 6 or 7, believe it's the power lines that run down the street in front of the house, but in the back yard it gives 12-15. But with my new 4X6 coil (V3 compatible) in the back yard I get a 2-3 on the probe but can go as high as 7-8 before it goes crazy. Loving the 4x6 but need to test how much depth I'm loosing.

So I think a 15 might be the norm with the 10" stock coil and providing no EMI or strange soil conditions.

 

[woodchiphustler]

You get it friend.

 

[bigsam]

I GOT THE FIRST VERIZON VISION WHAT CHANGES HAVE BEEN MADE FOR IT SINCE I BOUGHT IT?

 

[jgedde]

Here's the thing that's busting my brain... According to the manual the RX Probe is measuring the amount (as a percentage) of signal that is being lost. The behavior of the detector is that the higher the percent loss shown on the display, the lower the RX probe's suggested sensitivity becomes with 15 being recommended until about 11% lost is reached.

If signal loss is a low percentage wouldn't you also want a lower sensitivity because you're getting more signal back? The same thing with small coils... Less area means less received signal. Why a lower sensitivity not a higher one?

Am I missing something fundamental? Does a lower numerical sensitivity value mean higher RX gain? (sort of like discrimination numbers: higher = accept more)

John

 

[ak_1234]

What is being shown as a percentage on the screen is how much signal is being used, not lost. Since you're measuring ground, you probably don't want any more than 10% used so you still have enough sensitivity to not overload the machine when you see shallower targets. So, the stronger the ground, the less gain you'll want.

 

[alric]

I have an after-market pinpointer installed on the Vision and this causes the % shown on the probe screen to increase be 10% regardless of location. What implications will this have on the detector's performance?

P.S. I can turn the RX Gain up several points higher than what the probe screen recommends, while the after-market pinpointer is in-line... so, the pinpointer seems to decrease the accuracy of the probe screen.

Thank you,

Wes

 

[Carl-NC]

It just means the probe is not nulled as well as we null our coils. The increase you see on the probe readout is the contribution of the probe mis-null. It's really not a big deal if you are running at the recommended gain or even a few clicks above.

- Carl

 

[Carl-NC]

Hi Jerry,

Haven't seen your name in a while... I stopped by your house a couple of yrs ago and we chatted detectors. Good to see you got a V! If you Zoom on the Ground Tracking control you will see a Ground Probe readout that has the phases for all 3 frequencies. Be sure to Zero the screen. The DD coil helps a lot in bad ground.

Regards,
Carl