First Real Outing With My V3i...

[MHirschmann]

...And I obviously have a lot of questions. Firstly I ran everything in all stock programs and in custom programs. Boy, this machine really loves screw caps. I have NEVER found as many screw caps as I did today. With my E-Trac, screw caps are non-existent but the V3i seems to think they are an awesome find. I guess I have a lot to learn. A question I have, however, is how to get the machine stable? With my E-Trac, when it is running too hot, I turn down the sensitivity until it is stable and I am good to go. With the V3i, however, I tried lowering the sensitivity and the RX gain and didn't understand quite what I was doing.

1) Do you lower the sens or the RX gain first to stabilize the machine?

2) For those who also use Minelabs, how would you compare signals vs. the V3i? I rarely ever got clear repeatable signals today. This machine seems quite a bit "jumpier" in its VDI's than what I am used to with Minelab. This is my first non-Minelab machine so clearly I need to re-train my ears. Even on shallow coins, the VDI's seemed jumpy and I didn't dig anything beyond 6 inches. Does the V3i give solid repeatable signals or is this "jumpiness" normal for this machine? I hope that I just did something wrong and that there is an answer to all this. To what depth do you usually get a solid repeatable signal?

On a better note, I found more coins today than my seasoned friend with his E-Trac so I didn't do all that bad, I just was not quite in tune with what the V3i was telling me. It made a lot of noise to where I though the machine was falsing but I could not fix it by lowering sens or rx gain, so I don't understand how these 2 functions work with each other and when to adjust which one.

I will post a pic of my finds tomorrow in this thread and I greatly appreciate any help with my questions. Since I got the machine, I have only been able to use it in my test garden due to weather. It really amazed me how little I knew about this machine now that I actually got it out into the real world. I thought I understood it's language quite well in my test garden but the real world really kicked my @#$ today. Thank you all for your help and HH -Marc

 

[Larry (IL)]

It will take a little getting used to Marc like any new detector. Screw caps are no problem, they will show the wrong frequency dominate when you pinpoint. A quarter will be 2.5 dominate and a screw cap will be dominate in one of the other frequencies, usually the 22.5.

You might have EMI in the location you were hunting, but to get stability I would reduce the RX Gain, you can get it down to RX 6 without losing too much depth and while learning a new machine, don't worry about depth too much at first. I would suggest starting off with Hi Pro and reduce the Gain as needed and go have fun, the adjustments will fall in place on an as needed basis. The VDI will bounce around more on the V3i especially at depth and repeatable audio is the key at very deep targets. When i was digging relics at 12 inches, the VDI was of little use but I was still getting repeatable audio.

 

[Neil in West Jersey]

Boy, this machine really loves screw caps. I have NEVER found as many screw caps as I did today. With my E-Trac, screw caps are non-existent but the V3i seems to think they are an awesome find.

You should be able to tell them by their sound. They ring in as a 50 VDI which is the same as a zinc penny, but are a bit too big sounding for a penny. Some read like a quarter, but the dominant frequency is 7.5 KHz, not 2.5 KHz like a coin would be. (Check the strongest bar in pinpoint mode to see the dominant frequency.

For those who also use Minelabs, how would you compare signals vs. the V3i? I rarely ever got clear repeatable signals today. This machine seems quite a bit "jumpier" in its VDI's than what I am used to with Minelab. This is my first non-Minelab machine so clearly I need to re-train my ears. Even on shallow coins, the VDI's seemed jumpy and I didn't dig anything beyond 6 inches. Does the V3i give solid repeatable signals or is this "jumpiness" normal for this machine? I hope that I just did something wrong and that there is an answer to all this. To what depth do you usually get a solid repeatable signal?

Because the V3i uses up to 191 different tones, it will sound a bit jumpier with Tone ID on in certain programs. This is many more tones than the Minelab uses. You can change this in the settings if you want to set the VDI for a range of targets instead of one for each VDI. I may do the same to make 82-85 VDI one tone for quarters and large coppers, 77-81 VDI as another tone for dimes, etc. . Many of the presets use 4 or 5 different tones, such as the Coin & Jewelry mode,

I will leave the stability question for others to answer because I need to get to an appointment this morning. Good luck!

 

[corvair]

Marc,

Larry's feedback regarding pinpoint bars showing different for screw caps is spot on. That is the method I use as well and rarely dig one. For those that read a bit different due to decomposition, ground minerals or adjacent targets you can activate the bottle cap reject but I don't like to use it. I'd say my digging of screw caps is only about 10-15% of the total the V3i "sees".
The V3i can be made more stable if it is EMI by reducing the RX down to where Larry said. Freq. offset can also be used to help.You can also hold the coil up at waist level, pull the trigger for the pinpoint meter and while circling look for the freq. with the most chatter. You could then opt to run in single Freq. on the one that had the least chatter. One of these methods should work or a combination, usually the RX gain first though does the trick.

To aid in reducing VDI tones, do what Neil said and later you might want to load Magic's Pro program. That's the one I use 90% of the time now and gets me great depth. VDI jumpiness may decrease after you have made some of the previously mentioned adjustments. Shallower targets are usually very steady but depend on trash concentration, coin orientation in the ground, mineralization etc.., VDI can be jumpy on deep targets and the deeper the jumpier.

Hope this helps.

 

[Rob (IL)]

Question 1, lower RX first than bring up sensitivity if you can to make up what was lost by lowering RX.

Question 2, Most Minelab guys don't use the numbers. They go by sound and then the screen. Why, the numbers are too jumpy. At least that is how it is with my SE. Even on the SE screen a silver dime is IDed by the cursor jumping.

What Larry said works for the crimped caps for sure ( beer caps ). The aluminum twist caps are a little different especially when smashed.

The two are very different detectors for sure.

 

[MHirschmann]

Here are pics from my first hunt. Sorry, I meant crown caps, not screw caps. I am having a difficult time with the crown caps.

Thank you all for your feedback. So if I understand this correctly, I want to only start increasing RX gain once I run my sensitivity as high as possible without falsing? Basically, I crank up my sensitivity until the machine gets unstable, then back it down a bit, and then increase RX gain until it becomes unstable again and then back it down a hair. Is this correct?

I want to also thank everyone for the tips and tricks. I really need to learn the tones on this machine. My brain is so programmed to what good/bad things sound like on Minelabs that its going to be a learning curve to learn the tones on this machine. I feel like the tones sound much more "alike" on this machine than Minelabs. I know they are all adjustable but I dont want to change too much too fast.

I will keep you posted on progress and I appreciate all the help.

Best Regards,

Marc

 

[Rob (IL)]

No first get stable with Rx. Then you can try to increase sensitivity to try to gain back any depth you lost by backing down RX.

 

[MHirschmann]

Wow, I am confused! I guess I don't understand understand the relationship between RXG and Sens. I am guessing that RXG is NOT the same thing as "gain" on minelabs. So, how do you use these functions correctly? Would I start at say, sensitivity 70ish, and increase it until the detector becomes unstable, then back it down a couple notches. Also, start with an RXG of say 5, and work my way up once I find a sensitivity setting that seems stable? I guess I don't understand when to change which one versus the other and by how much. I understand how sensitivity works, but this is my first detector that has a feature such as RXG and I don't understand how to use it, when to use it and if to use it. Thank you for your continued help, I really appreciate it. HH -Marc

 

[Larry (IL)]

I think Rob has a drawing to better explain the difference, but the RX Gain, (receiver gain) amplifies all incoming signals including ground noise, trash and good targets.

Discrimination Sensitivity amplifies signals once past the RX Gain for the Motion mode channel of the detector.

All Metal Sensitivity amplifies the signals after the RX Gain for the All Metal hunt mode as well as the pinpoint mode.

Once you get these three adjustments set for you ground, you will very seldom need to mess with them again.

 

[Rob (IL)]

[attachment 226340 2012-03-14_181620.jpg]

 

[MHirschmann]

Thank you guys very much. The drawing makes more sense. Just to make sure I get it right, RXG is basically a built-in amplifier for everything the coil "sees." The good, the bad and the ugly, everything gets amplified more with more RXG and gets amplified less with less RXG? Too high and everything gets noisy, too low and there is not enough amplification to hear a target through threshold volume. Am I finally there?

Thank you guys very much for your help! I am hoping to make it on a night hunt tonight and will certainly give all this a try. Thank you again very much for your help.

Best Regards,

Marc

 

[Rob (IL)]

Pretty much.
First find the quietest frequency by using frequency offset.
After you get the RX set then fine tune the Disc sensitivity.

 

[Larry (IL)]

You are very close....... the threshold has nothing to do with the equation because you can adjust that as well. A very low RX Gain is good for searching for surface targets like a lost ring and higher RX gain with contribute to more depth but too much gain will amplify the noise and you will not be able to hear the really deep targets because of the noise. RX Gain 10 to 12 is what I use in my ground and changing the Gain to 15 will result in minimal gains in depth even if the noise level is low. If I remember right, you have to double the RX Gain to get an extra inch in depth, Rob will correct me if I'm wrong. So changing the RX Gain from 8 to 15 will result in less than an extra inch in depth. With Gain at 12 for me, in my ground, I still find CW bullets at 12 inches so going from 12 to 15, I might get another 1/4 inch.

 

[MHirschmann]

Thank you Rob. Boy I wish I knew someone near me in Minneapolis that also had a V3i. I haven't found anyone locally that is proficient with this machine but I surely could use some in-the-field training with someone that knows what he/she is doing. I have never needed this with a detector before, but this one surely makes me scratch my head more than any detector I have ever owned/used. I really appreciate the help Rob, Larry and everyone else. Hopefully I will get a hang of this detector soon. I know its early, I just figured I would have a smoother transition given my experience. I hope that doesn't sound conceited. If anyone on here is in the Minneapolis area, I would really like to get together with you to do some hunting and to pick your brain a little. Well thank you all for your help and I will keep you posted about my progress. HH -Marc

 

[MHirschmann]

Thanks Larry! I appreciate it.

 

[5900_XL-1]

IMO after working with the V3i for a while now...I would set the sensitivity to 83-85 and stop there with that setting until I felt good with the machine's stability. My experiences has been that I can tweak numbers up to the 90s and see some deeper stuff I buried, but the falses get monotonous for most all of the sub-4" treasure once I go to the open field to hunt. If I am missing 10"+ coins...well so be it. Running an RX of 15, AM of 65 and disc @ 83 is all in my little world of fun. I can easily drop RX(gain) to 5 or 7 and bump sensitivity to 92, BUT I just lost the depth I gained from moving away from RX = 15.

I chose to set mid 80's in disc sensitivity and "jam-up" the gain. If after that it gets real jumpy, I bump up a level of ground filter. It works for me. martin

BTW, I don't really focus much on depth and Vdi stability at max limits, i.e. 5-6+" when using a 6" coil, 9-10" when using a 10" coil, yada yada yada. I only dig iffy deep stuff when I have the priviledge of being able to use a shovel. It is a lot more fun digging moderate depth targets when I only have parks, schools and private yards. Also, I find that I waste way too much time analyzing jumpy targets if at the limit of the coil size. I just quit doing it for the time being and am FINALLY haviing fun with the V3i. m