RX Gain and False Signals

[Neil in West Jersey]

As I get more experienced with the V3, I am able to make more observations. Yesterday my focus was on the RX gain and the false signals I get when the gain is up too high.

I returned to a local site that I am familiar with and used a 950 coil, which is the coil that was used at the site in the past with my DFX. I know where the trash at this site is and I know the spots where the mineralization is a bit higher. I am also familiar with how other detectors act at this site, so it was a good spot to focus on the instrument rather than the targets.

The thing that I noticed about RX gain is that it is was not heavily affected by EMI when raised. It did, however, become more susceptible to false signals when the coil is lowered to the ground especially when the coil is bumped off roots or got tangled in underbrush The false signals I received when raising the RX control made it difficult to swing the coil very close to the ground, causing a loss of depth. Even when the RX gain is lowered well below the recommended gain this was a bit of a problem although not as much.

I noticed that the Sensitivity/Discriminate control had a larger affect on EMI. As soon as this is raised too high, the display began to jump around, even with the coil held in the air.

(I was running a modified Relic program with Mixed Mode ON,)

I guess now it is my job to go back to the D2 and see how it reacts in the same situation. I may have an overly sensitive 950 coil.

One other thing I noticed was at one point when I hit a dump site with extreme iron/trash the display began to lag behind the audio. It had a difficult time keeping up, and then the screen locked up. The audio still worked on the detector, but the screen and all the controls froze. I needed to take out the battery to reset it. I am not that concerned because I have had occasional freeze ups on every digital detector I ever owned.

 

[Aurium]

Interesting observations. However a screen lockup although an annoyance while detecting if you have to pop the battery out and back in. Is something I hope the designers are aware of. I know it's a not a Toyota sized problem, but it is something that as a designer I would want to make sure never happened, as it affects customer satisfaction.

 

[Rob (IL)]

I think you are right about the lockup Neil. Nothing to worry about. Like our computers never have to be rebooted. Rob

 

[jbow]

One other thing I noticed was at one point when I hit a dump site with extreme iron/trash the display began to lag behind the audio. It had a difficult time keeping up, and then the screen locked up. The audio still worked on the detector, but the screen and all the controls froze. I needed to take out the battery to reset it. I am not that concerned because I have had occasional freeze ups on every digital detector I ever owned.


Thanks for posting that. Now I will know what to do if it happens to me, also... I wont freak out! FWIW, my E-TRAC occasionally shuts itself off in the middle of startup, it plays a couple of notes then shuts back off. It always starts uo just fine when I press power again, so I don't worry about it. I agree with you about digital electronics, they all do weird stuff now and again. It seems that digital is where all the companies are headed for the most part.

I would like to see more hybrid digital/analog machines. The whole thing right now (unless you want to spend 5k and carry something really heavy) is better seperation or unmasking. It seems that most all decent detectors get about the same depth but the machines that are making the finds are the ones that can tell you there is a dime down there on top of that RR spike and nail. Many good targets aren't coming from 14" deep but are coming from 4" to 6" and they are still there bacause yesterdays machines couldn't "see" them.
Now, I don't know if that is all because of computer code and faster processors... but I suspect that it is. I'd like t osee something with a combined analog meter and digital number meter. Better yet, a hybrid design with a true computer chip, something with some real processing power. Putting the CPU in a small backpack or chestmount design might work. I know that power for the thing would be a challenge, providing enough power to run the CPU and a cooler without adding too much weight would be a design challenge but not that much of a challenge. I think it could be done with laptop batteries and maybe just build the power supply into a backpack design. Imagine what sort of unmasking and seperation could be had using something like a core i7 processor, combined with a digital and analog meter option, good D/A converters for great audio... but, as I said... i'm just a dreamer.
Also, with that sort of power it really should be a turn on and go machine, with everything truly as self adjusting as you might want it to be. I like a few options but not too many. That is the one thing that I don't like about the V3.. I get lost in the options. There is always something I forget to tweak. Maybe if it was the only maching I used it would be easier. That will never be the case though so.. i'll learn it eventually.

If I only wanted depth i'd just get one of these...

J

 

[Larry (IL)]

Once you get the V3 adjusted to your ground J, it is pretty much a turn on and go hunting machine. Sure you can tweak and tweak some more but I think sometimes we can do too much tweaking.

 

[Neil in West Jersey]

One thing I keep emphasizing is the V3's (and the DFX's) sensitivity to very small targets. I am constantly digging TINY targets at 5 & 6 inches. I am finding a lot more cuff buttons than I used to!

 

[cloudbuster]

Once you get the V3 adjusted to your ground J, it is pretty much a turn on and go hunting machine. Sure you can tweak and tweak some more but I think sometimes we can do too much tweaking.

spot on larry !! people spend to much time fiddleing and not searching, i have settled pretty much on one custom program now which suits my ground and technique, finds rate has shot up and the detecting expierience is the one i want ...

all the best rob

 

[nw1886]

I've had that lock up happen a couple times. It happened in the same kind of situation as you guys and had to be rebooted both times too clear up (but wasn't an ongoing occurrence). Have been finding stuff in iron halos consistently and predictably (Seeing the iron is only a good thing!)

 

[jbow]

Larry,

I am my own worst enemy sometimes. It is sort of like when you were hungry 3 hours ago and didn't eat... and now nothing seems like what you want. Or going into a store that carries 1,000 different brands of beer and ale. If I pick one out after a few minutes of looking i'm fine but if I go down the display several times... I can't decide and wind up just getting something.

I'm that way with the V3 once I start tweaking, so I try to not tweak too much. Then I come and read about this and that and want to try it all... actually, I want to try everything and learn everything about the V3 and every other detector. That is the main reason I have so many detectors, I like detectors as much as I like detecting... almost. I hesitate to sell one because I cannot tell you how many times I have sold something only to later realize the value of what I had. I've sold a few detectors without looking back but I am waiting on some others. Then there is the thing about trying to learn more than one detector at a time. I am convinced that, particularly in relic hunting where you have to deal with who knows what sort of trash and ground, no one detector will do it all... so, I know I am not spending enough time with the V3 but I try to use it on every outing. I think I am going to try to make sure that it gets at least 2/3s of my tectin' time. I am really liking on the F75 LTD too and I have not given up the ET. The T2, SovereignGT, and Tejon travel with me in case I think I need them but the SE is living in my closet right now... I have been thinking that the SE with the Pro coil may be better than the ET for old coins because of the way the cursor jumps and because the multitones in ferrous are better (more info IMO).

Anyway, thats probably more than you wanted to know but bottom line... I want to know all about the V3 and it is hard for me because it is my first Whites and because it isn't getting my total attention. Maybe I should give it a 60 day period for exclusive use. I used an F75 as my main machine for about 2 years, one year of that time I was trying to learn the Explorer SE. I was hunting almost every day during spring, summer, and fall. I'd hunt the first hour or two with the SE then switch to the F75. I would go from finding nothing to finding a lot of goodies in the same place... finally I sort of got it figured out. I had been hunting in conductive/multi. When I switched to ferrous/multi... it began to make sense and I began to make finds. (This was relic hunting, not coin) When I got the ET I put it in ferrous, 2tone, digital screen and it was like an old friend right out of the box (the ET will not flase in 2tone/ferrous).

Anyway, I think I am going to have to put the others aside and use the V3 exclusively for a couple of months until it begins to speak to me. I have several places lined up so... i'll let you know how it goes.

One other thing... the coils... everyone seems to love the 5.3, I don't like it at all. I haven't used a 950 for more than 10 minutes, I didn't like it either. I think it is because everything I have used in the past has been DD based. I love the D2 coil and I love the 4x6 shooter, they both seem to do very well. I wish there was an 8" D2 for a little less weight, something inbetween the 4x6 and the 10" D2. Do you have a recommendation? Maybe I should get a 950 and give it a real chance.

Well, thanks for listening.

Julien

 

[jbow]

The V3 is the only machine that I have found a percussion cap with. I think the Tejon is capable but the V3 with the 4x6 will cut it in really bad ground. The place I found this cap has been really hunted to death. The place is like "hunted out" squared... I may start taking some time with the V is 22.5 alone.

J

 

[Larry (IL)]

I too think an 8" or a 8X10 SEF or DD would be the cats meow for the V3. I have talked to White's engineering and and like some other projects, it was on the back burner the last time I talked to Carl. I think it will just be a matter of time.............. I have asked for an evaluation unit from Kellyco on the 6X8 SEF but it must have fallen on deft ears.

I think if you give the V3 the time you are thinking about Julien, you just might consider thinning your stock down, I did and I was a big Minelab guy as well as White's.

 

[ramases]

I too think an 8" or a 8X10 SEF or DD would be the cats meow for the V3. I have talked to White's engineering and and like some other projects, it was on the back burner the last time I talked to Carl. I think it will just be a matter of time.............. I have asked for an evaluation unit from Kellyco on the 6X8 SEF but it must have fallen on deft ears.

I think if you give the V3 the time you are thinking about Julien, you just might consider thinning your stock down, I did and I was a big Minelab guy as well as White's.

Hi Guys

Well, have finally managed to get a few hours on a ploughed (UK) field and I now have an idea how to setup my 10X12 SEF. As expected, recommended Rx is a lot lower in the 22.5KHz mode but in single frequency 7.5KHz it wasn't a lot higher (recommended 7 instead of 4). Interestingly, my 3-frequency mode (based on HI-PRO) also gets a recommendation of 4 - HOWEVER - I can run at quite a bit higher. Today on a much-hunted field I was able to double the Rx to 8 (Sens 85/70) and the SEF ran smooth as silk with 15% signal loss. I finished up with a handful of buttons, a few musket balls and lead bits, three Georgian copper pennies and a hammered silver Commonwealth halfgroat (about 1650) - my first hammered of the year. All-in-all I'm very happy with the SEF. Signals are sharp and pinpointing is easy once you have the hang of it. I still need to make a depth assessment on a piece of virgin ground but so far, I am pretty impressed.

 

[Larry (IL)]

Congratulations on the great finds. I use the 10X12 as well with similar settings.

 

[chris poteet]

I have been having a lot of false signals with my 10 D2 coil so I did the coil test bumped up the rx to 15 turned on tx boost no overload. that means i have a good coil? but now since the test no matter what the ground condition is the suggested RX gain has been 15 on every ground test plus i did an air test on a quarter its right on up to about 5 inches after that it say's dime/penny? can anyone help with some info please?

 

[Larry (IL)]

We are going to need more info to offer some advise Chris. What program are you using, what is your RX set at, how about your Sensitivity discrimination and filters? Most often, falsing is caused by having the RX or Sensitivity Discrimination turned up too high for your ground conditions. I was having falsing or EMI problems yesterday and I was hunting with the RX at 2 and Discrimination at 70, offset +3 to quiet it down. I still pulled out a 1891 IH cent at 5-6 inches with the mild setting, so don't be afraid about losing depth by turning things down to get stability.

 

[chris poteet]

larry i was in the stock cion&jewelry when i done the coil test and after the test i set every thing back to stock settings.but no matter what program im in or what type of ground im hunting the probe in the live controls always says the same ( best rx gain is 15 ) i even switched coils to my 6x10 dd and the probe said best rx gain is 15

 

[Larry (IL)]

Regardless of what it says, you may have to back down the RX and Sensitivity to gain stability. Your falsing may be coming from interference and have nothing to do with the ground.

 

[chris poteet]

im going out to a new place today i will try bumping the gain down along with sens. let ya know how it does. also never had a problem before with it falsing found over 500 clad with it .

 

[bud212002]

I had a major issue the other day. I could no get my D2 to do anything even with RX at 3 and disc. at 55. Sweep, adjust, sweep, for 10 minutes, and thought my D2 had bit the dust. Then happen to think, I have new boots on??? They box said nothing about steel toe, but they were!! Glad I was by myself for this hunt. Almost as embarrasing as cursing my V3 the first week I had it because it would not work correctly. A friend said, does those power, telephone, tv cable, wires your standing 15 feet under affect it??


Also, I pay no mind to the Recommended Rx settings. You are better off setting it based on your ears recommendations.

 

[nemesisnow]

I had a similar experiece today with my V3 - first day out with it - coin program worked flawlessly - coin and jewlery program was doing the funky chicken - I will be going out again tomorrow to play with the settings. learned alot from reading this thread - tyvm

Cheers

Nem

P.S. I did pull out a nice silver mexican ring within 10mins of using the machine - so im pretty much thrilled!