CZconnoisseur
Active member
Have been itching to spend some hours swinging the new 9" HF round coil all week, and last night I got the chance! Spent 3 hours total around my front yard and in the sidewalk strips seeing what was what - and was really pleased with the results.
Started in the coin garden - an area of sidewalk strip that I've recently buried 12 coins total; 4 silver dimes, 4 Indian cents, and 4 nickels at 3,5,7, and 9-inch depths. Mike and I cleared off all of the easy targets in the area on 2 previous hunts, where we found a few old things here and there. With the 11" coil I was having trouble getting the 7 and 9 inch coins, presumably from the mixture of our hot soil, years of salty roads and sidewalks, and of course public littering. This area pushes 5-6 bars of mineralization at spots, and deep targets with the 11" coil would get scratchy and smeared.
I tried 18kHz with the 11" LF coil and it didn't seem to make much difference in getting through to the deeper coins - there wasn't hardly any improvement in the signals. Maybe the 9" LF coil would hit the coins better, and it would be interesting to compare all three coils head-to-head once I get the video glasses repaired or replaced. Those coins aren't going anywhere so maybe one day....
About the first thing I noticed with the 9" HF coil is that coin-sized targets sound BIG - it zooms in so well on smaller items that coins are "a piece of cake" for the HF model!!! First good target was the bus token - it sounded loud and clear, registering a 59-60 at 6" deep. Out of the hole, the token in air reads 59-60 as well! Went on to dig a lot of "round" items, screws, nails, bolts, clothespin springs...anything round whether ferrous or non-ferrous produced a decent "dig me" tone, it got dug.
Another obvious difference was the upper-end VDI compression - I used 28.8kHz the entire time which made zinc pennies indicate 90, copper pennies 94-95, and a half dollar reads 97-98. Beavertails, ring pulls, and square tabs would come in loud and clear at low 70s, mid 80s, and high 80s, respectively; and our old friend aluminum foil liked to hang around the 50s when it would even give VDI.
Foil is surprisingly easier to pick out over a deep, more solid non-ferrous item - there's a little crackling and smearing with foil but the 50s and low 60s VDI has given it away every time so far. A nickel reads "70" at shallow depths, so imagine the disc area for other detectors from 00-69 comparatively for "nickel and below disc!"
"Up-averaging" with the 9" HF round coil is almost non-existent, you won't get much if any VDI shift on a deep fringe target, especially coins. All of the recently buried 9" deep coins (silver dime, Indian cent, and nickel) are soft, squeaky hits with surprisingly stable and accurate VDI. My 12 coins are ALSO buried under overhead power lines - and I noticed little if any EMI last hunt....If I remember correctly the 9" nickel returned a slightly jumpy mid70s VDI, but with a confident audio component....it only sounded 5-6" deep!
Probably the best target dug last night was an aluminum button about the size of a penny - it was next to the sidewalk at 10-11" deep. Initial scanning gave a soft, squeaky audio with 82-83 VDI...got it out of the hole and it locks on a VDI of 83! I was really hoping for a coin, but this target made me a believer.
Tomorrow night the HF coil is going to work in some well-hunted ground - it should be interesting to say the least!
Started in the coin garden - an area of sidewalk strip that I've recently buried 12 coins total; 4 silver dimes, 4 Indian cents, and 4 nickels at 3,5,7, and 9-inch depths. Mike and I cleared off all of the easy targets in the area on 2 previous hunts, where we found a few old things here and there. With the 11" coil I was having trouble getting the 7 and 9 inch coins, presumably from the mixture of our hot soil, years of salty roads and sidewalks, and of course public littering. This area pushes 5-6 bars of mineralization at spots, and deep targets with the 11" coil would get scratchy and smeared.
I tried 18kHz with the 11" LF coil and it didn't seem to make much difference in getting through to the deeper coins - there wasn't hardly any improvement in the signals. Maybe the 9" LF coil would hit the coins better, and it would be interesting to compare all three coils head-to-head once I get the video glasses repaired or replaced. Those coins aren't going anywhere so maybe one day....
About the first thing I noticed with the 9" HF coil is that coin-sized targets sound BIG - it zooms in so well on smaller items that coins are "a piece of cake" for the HF model!!! First good target was the bus token - it sounded loud and clear, registering a 59-60 at 6" deep. Out of the hole, the token in air reads 59-60 as well! Went on to dig a lot of "round" items, screws, nails, bolts, clothespin springs...anything round whether ferrous or non-ferrous produced a decent "dig me" tone, it got dug.
Another obvious difference was the upper-end VDI compression - I used 28.8kHz the entire time which made zinc pennies indicate 90, copper pennies 94-95, and a half dollar reads 97-98. Beavertails, ring pulls, and square tabs would come in loud and clear at low 70s, mid 80s, and high 80s, respectively; and our old friend aluminum foil liked to hang around the 50s when it would even give VDI.
Foil is surprisingly easier to pick out over a deep, more solid non-ferrous item - there's a little crackling and smearing with foil but the 50s and low 60s VDI has given it away every time so far. A nickel reads "70" at shallow depths, so imagine the disc area for other detectors from 00-69 comparatively for "nickel and below disc!"
"Up-averaging" with the 9" HF round coil is almost non-existent, you won't get much if any VDI shift on a deep fringe target, especially coins. All of the recently buried 9" deep coins (silver dime, Indian cent, and nickel) are soft, squeaky hits with surprisingly stable and accurate VDI. My 12 coins are ALSO buried under overhead power lines - and I noticed little if any EMI last hunt....If I remember correctly the 9" nickel returned a slightly jumpy mid70s VDI, but with a confident audio component....it only sounded 5-6" deep!
Probably the best target dug last night was an aluminum button about the size of a penny - it was next to the sidewalk at 10-11" deep. Initial scanning gave a soft, squeaky audio with 82-83 VDI...got it out of the hole and it locks on a VDI of 83! I was really hoping for a coin, but this target made me a believer.
Tomorrow night the HF coil is going to work in some well-hunted ground - it should be interesting to say the least!
