Rob,
I've had my V3i for about two months now and have been using it extensively (I'm recently retired and have easily put over 100 hours on it in the field). Which means I am still learning what the V3i is capable of, but perhaps some might find my experiences helpful. Nothing I have to say will be new to any of the experts on this forum, and I've gained enormous amounts of information by reading their posts. Below is what has worked best for me so far.
State: Missouri
Program: My favorite is the Hi-Pro with these changes:
Search using Intensity Fade[8] Res[5] Base[70] Recovery set to [70]
Analysis using Consistency with a quicker recovery (50 with the D2 coil) and Fade[13] Res[4] Max[8] - I "wiggle" the coil over the pinpointed object to get a better "look" at questionable targets from different angles.
I discriminate out -95 to -88 and use a low tone for everything between -87 and 0 as I like to hear when I'm in iron rich areas. I set tones and colors by Icon range for good targets.
RX setting: I set RX[8] AM[75] Disc[85] - I find this to be a quiet and deep seeking combo for my area. I will tend to raise DISC before upping the RX gain in most situations, especially where trash targets (including iron) are frequent...in open fields or wooded areas containing minimal targets, I'll up the RX to as high as 13-15 as long as EMI is not a problem. However, it becomes super sensitive with high RX settings, so expect to find EVERYTHING! In high iron areas (like around farm buildings, adjacent fields and some city parks/yards), I find a lower RX number usually equates to excellent depth with less masking and falsing....nails will still show as a good target at the correct angle, but turn 90 degrees and most of the time it will show up as iron on the Spectragraph...and I've dug enough of those questionable targets to feel comfortable in passing them up with one caveat, if pinpoint shows a dominant 2.5 freq. bar from any angle, it might be a coin alongside iron, so I dig it.
One last thing...personally I don't pay too much attention to VDI numbers on anything deep....the machine is so sensitive I've come to expect jumpy VDI numbers on deeper targets as nearby items (or mineralized/iron laden soils) will affect the readout, instead I keep the RX setting in the middle ranges and listen for a good tone and look for consistent bars building up in the higher ranges of the Spectragraph. To me, the Spectragraph is what separates the V3i from its competitors, pay attention to it and you shouldn't miss the deeper targets. When I want more stable VDI numbers and even quieter operation (especially in iron infested areas) I usually go to a correlate program I've set up to achieve this. You will sacrifice some depth for the added stability, but in trashy areas it may be an acceptable alternative. The choice is what makes the V3i so appealing to me.
Depth: With the D2 coil, my deepest "in the field" find on a dime sized target was a silver dime at 10" in an old city park, but I've found many other coins (silver, copper & clad) in the 8 to 9 inch range and a silver quarter at just over a foot at an old home site. In my test garden I get semi-consistent hits (definitely stop and check it out signals) on a 10" clad dime and solid (no mistake) hits on a dime a 9" and clad quarter at 11". Note: In the test garden, with RX [8] and Disc [89] I achieved the above. Ground probe showed VDI of -93 and Strength readings of 3.9%, 3.8% and 3.8%. It was the best combination of quiet operation and depth I found while testing. Using TX boast did give better hits (tonally and visually) when over the target, as did upping the RX & Disc, but doing so also tended to add more noise (chatter) and more random spikes to the Spectragraph display when searching (IE: when not over a target) which might cause operator fatigue over time.
Okay - I know, way too much data in response to simple questions. I'm sorry about that, I'm hoping some may find this information of interest.
Steve
Sorry- on more point not often mentioned, this machine has EXCELLENT target ID and separation on items up to the 6"-7" (you know, where most items are found), and that's where the analysis tools such as Sizing, Polar Plot and even the 3 frequency pinpoint mode make identifying targets easy.