|Posted on March 27, 2012 at 7:55 AM||comments (5)|
In the White's V3i manual it mentions that the V3i can get more depth by channeling all of its power to a single frequency. I had been thinking about trying Single Frequency mode at my "hunted out" sites for a while, so I decided to get back to a site that will be undetectable in another week or so due to the rapidly growing vegetation. I was thinking that single frequency may give me the edge I needed to get what I may have missed before, and I was right!
The three frequencies that are available are 2.5 KHz, 7.5 KHz, and 22.5 KHz. Lower frequencies are better for silver and copper coins, but the detector loses sensitivity to low conductive targets like gold and small buttons, so I decided not to go with 2.5 KHz. Instead I chose to work with 22.5 KHz, but quickly realized that I was getting a lot of positive readings from iron. I switched to 7.5KHz and it did away with the iron problem. This frequency is a great compromise for both coins and gold.
Almost immediately I was easily getting deeper signals using this frequency. I dug some deep tiny junk, and then an Indian Head that read solidly at 7.5 inches. I was surprised how clear and consistent the signal was! Much better than Best Data! A few minutes later I got a tiny ball button which was also fairly deep but gave a bouncy signal which is typical of these tiny pieces of metal.
After a while I got a solid 79/80 VDI reading at 8 inches. Again I was surprised at the strong, consistent signal. Hoping to find a Barber or Mercury Dime, I was thrilled to see a small copper coin, which I immediately recognized by its size as an early US Half Cent. (This was Half Cent number three for 2012. Prior to this year I had only dug two half cents since 2001!)
While secondary to raising gains (RX, All Metal, and Discrimination), single frequency is a great way to add a few more inches of depth!
For more information on how frequency affects VDI and sensitivity, see my VDI Normalization chart by clicking here
|Posted on May 16, 2011 at 1:40 PM||comments (2)|
I know there have been many recent forum posts on the topic of which is the best VLF metal detector for finding gold, the Minelab E-trac or the White's V3i. The different opinions posted are often conflicting, confusing the potential buyer, so I thought a simple comparison of the two can be helpful to someone who is considering buying either detector.
First of all I want to state that they are both great detectors, but each does have its advantages. My detecting buddy uses the E-trac, and I use a V3i. We are constantly comparing questionable signals. On deep coins, there is little difference on the depth capabilities on each of these detectors when it comes to deeply buried copper and silver coins. In some instances, especially in more difficult soils, I have seen the E-Trac pick up an extremely deep signal that the V3i barely gets a whisper. An experienced V3i user would certainly investigate such a signal further, however a novice may not. For this reason, I would say the two are nearly equal, however the Etrac may have an ever so slight advantage on deep silver and copper
When it comes to small targets like gold and tiny pewter buttons, however, the V3i has a distinct advantage.
A few weeks back I was testing different targets in my yard with my newly purchased Minelab Excalibur 1000. I was very surprised that the Excalibur could not detect a tiny, hollow 14K gold charm unless the coil was within a half inch of the charm, while the V3i sounded off nicely at more than 4 inches. The All Metal setting picked it up at an additional half inch on the Excal, while the V3i did at greater than 6 inches. When the V3i was switched from Multi-Frequency- Best Data mode to 22.5 KHz, the signal strengthened even more.
Now I was curious to see how the Etrac fared on the gold charm, so I made sure I brought it along on my next hunt with two of my buddies It turned out that both were ETrac users, so this would insure that the results were accurate from unit to unit.
I carefully placed the tiny target on the ground and stood back so my detector did not interfere and waited for his Etrac to go through the Noise Cancel process. As my friend passed the coil over the target there was only a faint blip sound within an inch of the target. The other Etrac had the same result.
Here is what you should consider before you buy. The V3i is more sensitive to small targets such as tiny gold charms, earrings, etc. If gold jewelry and relics (such as small pewter buttons) are your focus, the White's V3i may be the best metal detector for you, while if your focus is on coins and higher conductive metals such as copper and silver, the Etrac may be a better choice.
|Posted on December 25, 2010 at 9:45 PM||comments (0)|
Back in September, I broke the toggle switch on my White's Spectra V3 metal detector. Since the detector was still covered by White's two year warranty, I thought it would be a perfect opportunity to have the detector upgraded to the new Spectra V3i. The upgrade included a new pod display, software upgrades and eight new features designed to further enhance the users metal detecting experience.
Being an experienced V3 user, I was anxious to see how the V3i performed compared to the V3. I was also curious to see if the new features were worth the investment for the upgrade. My first two outings were simply for the purpose of learning the new features and comparing performance to the pre-upgrade status, so on both of these outings I returned to a site that I knew well. I knew it has been "cleaned out" by myself and others before me, but I also knew where the deep iron was and where the higher concentrations of trash were. This was an excellent opportunity to try out the Polar Plot feature, which allows the user to see the phase and the strength of a target in each frequency on a vector graph. Good targets display straight lines on the positive side of the scale, while bad alloys show curly or squiggly lines. I found this feature to be a huge asset in determining valuable targets from junk. With a few changes in the configuration menu, I was able to make this my default, replacing the sizing analysis feature (which is the factory default setting) when the toggle switch is pushed forward.
Another new feature I was anxious to try out was the Stereo Mixed Mode, which divides up the sound from the All Metal and the Discriminate Channel, allowing the user to hear All Metal in one ear, and Tone ID in the other. I tried this feature out on both of these outings and did not care for it at all. I found it made the detector a bit unstable, and I had to lower my Gain control to stabilize the detectors operation. I could not get used to the different sounds in each ear, so I decided to go back to the default Mixed Mode, which still allows the user to monitor both the All Metal and Discriminate channels at the same time.
I had noticed on these first outings that the V3i ground balanced a bit better than the V3, with a nice steady threshold. However I also noticed that the Autotrac feature has a tendency to over-track, even when the Track Speed is reduced. In my area, the soil is fairly consistent and the AutoTrac feature is not necessary, so this is not much of an issue. I simply perform a ground balance and click on Track Lock in the Ground Tracking menu.
Overall, I was happy with the performance on both of these outings, although I had not made any good finds. The Polar Plot feature alone made me happy I made decision for the upgrade.
On my next outing, I decided it was time to see how the V3i performed on deep silver, so I returned to a site I had briefly detected during the summer of 2009 with my White's DFX. It was the dried up lake bed of a former resort. On the 2009 outing I had detected a small patch under a diving platform, finding old beach tags and one Barber Quarter. This was the perfect opportunity to see how well the V3i performed vs. the DFX.
Upon returning to the site I found a trash free spot to ground balance the detector. After performing my ground balance, I swept the coil back and forth over the muddy surface. It was not long before I got the high, smooth tone of a silver quarter at roughly 8 inches depth. I made a nice deep plug and pulled out my first ever Standing Liberty Quarter, dated 1917! A few minutes later and I had my second silver of the day, an early Washington Quarter. I dug a few more silver coins and some Wheat Cents, all at depths varying from 6 to 10 inches. Then, I moved up to the former lake shore and got a foil reading with a VDI jumping from 5 to 7. Pushing the toggle forward, I noticed nice straight lines extending from the center out, with the 7.5KHz showing the strongest signal. This typically indicates a good target. This was a very shallow target, and as I flipped the plug, I caught a glimpse of yellow gold through the leaves and brush. I quickly bent down to retrieve a gold crucifix inscribed with initials and the date 4/3/55. Now I was really starting to like this detector! I dug a total of 8 silver coins including the SLQ and a 1905 Barber Dime on that outing. On a visit one week later I also dug a gold men's wedding band which was 4 inches deep, as well as some more beach tags and a Victorian Era gold plated ring.
So far I had been happy with the results, but I wanted to give it one more test, the EMI test. I visited a site that I had detected 2 years earlier with my DFX. The site was a former farm field which had produced some good finds in the past, but lately had been turning up only trash. It was another good site to see how high I could set the detector's gains, and how it would handle the electrical cables which ran along the edge of the field. The DFX had a bit of trouble with EMI near these cables, so I thought single frequency mode may be a better choice for the V3i. With my RX Gain set at 10, my Discriminate Sensitivity at 94 and my All Metal Sensitivity set at 74, I approached the wires. I began to get some interference in the 7.5KHz frequency, so I clicked on "Transmit Frequency" on the Live Controls menu, and lowered the Transmit Frequency Offset down a few notches. The V3i returned to its smooth, steady hum.
I worked the field for a while, finding some trash items and a small cuff button. I noticed that the V3i was picking up small bits of foil at depths of more than 10 inches. This was excellent depth that i had not been able to attain before the upgrade. (Note: I accept all targets above -41).
After a while I moved across the road to a small lakeside park surrounded by woods. I was not the first to detect here. There were plugs replaced in the ground with twist off tops buried back where they were found! After a frustrating hour or so, I began to return to the car. I got within 20 yards of it when I got a penny/dime signal at 4.5 inches. Thinking this was one more for the coin jar, I was very surprised to see a beauty of an Irish Halfpenny from the 1780's! Not a bad way to end the day!
Overall I have been extremely happy with the results of the V3i upgrade as follows:
Pluses: Polar Plot & Loop Selection: both great additions.
Minuses: Stereo Mixed Mode is not for me. Autotrac feature tends to over-track and drift when gains are raised. I usually use the Lock Trac feature which locks the ground balance to where it is balanced so it is not much of an issue for me at all, however users in areas where ground conditions change rapidly may find this to be a problem.
In summary, anyone who is still using a V3 or a Vision metal detector, pack up the control box and the headphones and send them out for the upgrade. You will be happy that you did!