Jim in Idaho

Man, what awesome finds! Nice work! Jim

I've always had trouble getting the GB and Threshold exactly right on my TDI SL. After seeing Karelian's thread on the vernier knob, I decided to see what I could come up with. The problem with the control the guy suggested to him was that it had limited movement. Ideally, you want the vernier to turn as many turns as need to move the potentiometer through it's full range of travel. After hours of searching I found what I needed. A solid brass and stainless vernier with a 1:6 ratio. One full turn moves the GB pot about 1 1/2 numbers. I can now easily get the GB to that "just quiet" point, and it stays put. No more tree branches, or coat sleeves inadvertently moving the controls. I can easily set the Threshold to the very edge of my hearing, and as the batteries discharge and the Threshold creeps up, I can make a tiny adjustment and it's back on the money. As far as immediate and stark difference, this is the best mod I've done. It took me several hours to machine the bases, but the way I made it requires no physical mods to the machine. Remove the pot nuts, put the base on and replace the nut. I had to make shims for the pot shafts, as the verniers are made to fit a 1/4" shaft, and the shafts on the pots Whites used are .234". Had to make some very thin-walled round shims to glue inside the vernier sockets. I'm planning on selling these kits fort $150 for both controls, or $75 for a single. If anybody is interested, you can PM me here. Now I'm really looking forward to our Nevada trip in June! My SL is about as good as an SL will ever be. It's going to be interesting.

What a great day! Out with your son, and cool find, too. When I was in the Air Force, 50 years ago, I used to go to Huntington to body-surf. Great waves, but you'd slowly get pushed along the beach as you went in and out. Pretty soon it was a LONG walk back to the car. Brings back memories...Thanks! Jim

I wouldn't bother buying the 12DF. You should be covered for depth by the Hi-Q, and the 12DF is a beast to swing for very long, IMHO. Jim

Sorta looks like detector prices are dropping...probably due to the overall economy. Jim

I'm in complete agreement on the Signagraph display, Steve. Wish they had it on the GM24K. Jim

I can't advise, Jeff, but I sure like my DFX. There's a lot of iron in the desert soil where we've been detecting lately, and I'm keeping up with my buddy and his 'Nox. Certainly, there are places where he'd have some edge, but we haven't seen it yet. Jim

Quite a deal, Steve. Detectors are really getting cheap! I'd be all over that if I didn't have a GM24K. 🙂 Jim

They could also have applied for a "provisional" patent, which confers no legal protection. It simply locks in your date, so when you apply for a regular patent, the date is the date the Provisional was applied for. But, having the Provisional allows you to put "Patent Pending" on your products. A Provisional is only good for 1 year. A Provisional is cheap, and much easier to obtain. Jim

If Minelab has the patent, the way it works is public. When you apply for a patent you can request it not be made public, but only until the patent is issued. Once the patent takes effect, the application, including the operating theory, become public. Jim

The problem with this, I found out, after I bought one, is that it only turns the pot 1/2 turn. That does NOT give you the full range of ground balance. That is NOT going to work for me. What you want is a vernier that gives a full turn on the control shaft. Took me 3 hours, but I finally found one. here's the link: https://mgs4u.com/product/vernier-reduction-drive-14-inch-to-14-inch/?v=8c21c2bc4529 It doesn't look like it includes a knob, but that's easily solved. I'd take $20 for the one I bought in Karelian's pic...it cost me $35.00 Jim

Nice work, Steve! I think the resistors in that circuit are to prevent the coils "ringing" when the pulse turns off. Note both coils are wired in series, so the pulse fires them together. A folded mono is the same. You just take a larger diameter coil, and squeeze it together so it makes a figure-eight with one end half the size of the other. Make a half-twist at the juncture. Then you fold the small portion over on the large portion, and you have a folded mono. Electrically, they're pretty much the same. I don't know where they put the damping resistor on the FM. Jim

Good explanation, Steve. The engineers are now trying to get around the need for the DF by using spiral windings. But, it seems to me they're going to have the same sensitivity to ground minerals as the DF's. I agree the DF's are probably mono coils, though I guess you could make a DF concentric, though it would be complicated.:-) Jim

The inner and outer coils are wired in series on both coils, Rick. Not a huge difference between that and a folded coil. Reg Sniff developed the folded coil to get around White's patent on the DF. Pretty similar in performance, but in my experience the DF's have the edge in sensitivity.....especially the 7.5 over the 5 x 9 FM. I don't know if the DF's are mono coils, or not. Jim

All the best, Rick. Hope you find some good stuff. In my testing, not a great deal of difference between Sadie and 7.5DF. One does better on some targets, the other better on others. Very close. And, as you said, both a real pleasure to swing. Jim

I recover old bullets fairly often. I use the <Coins & Jewelry> program. Generally I use ground filter 3, and Preamp gain of 2 or 3. I use a 6 x 10 DD Eclipse coil, unless there's lots of iron trash. I also use the <Best Data>. Jim

Incredible find! What a transformation. Jim

I'll have to check with my source. Jim

I guess I forgot to post that we found out the business that gave out the token (Miller's Famous Bar & Resort) was located in Kansas City, MO. Not sure about the year. Appreciate the info, GB! Jim

Whites has never done the mod of changing the values of C20 & C21, Lonnie. The only Reg Sniff mod they started doing at the factory (possibly in 2015) was removing C56, and the diodes D20 & D21, and installing a jumper across two of D21's terminals. That's usually called the "second" Reg S. mod. The first, which resulted in a faster sweep speed while still being sensitive to small gold, was swapping C20 & C21, which are .47ufd caps, and installing .22ufd caps in their place. That mod is not too hard to do. The "second" mod is much more difficult, and requires some serious soldering skills, and a good soldering station, with adjustable temperature. That second mod results in better sensitivity. I'm not sure either makes much difference in beach detecting. Jim

I was thinking they probably used rubber. Ij told Chris it might make an interesting project, though with a 2hp Honda, and maybe more rigid paddles. Have to think about that.:-) Jim

Glad he pulled through, Strick. Where was he bitten? I have get Heidi a rattler shot every year, but I still worry about her. Mainly because she runs around, and would probably run right over one....LOL Jim

Hey Clark. Send me a pic of the underside of that broom, when you get a chance. A closeup, too. Thanks, Jim

It's a wheel kit for a power broom. The power broom is to move dirt off bedrock to get to the gold. Interesting use for a battery-powered broom. Jim

Clark, if you tell anybody I made that, I'll have to kill you...LOL I wanted it light, so made it all of aluminum, besides the wheels and axle. I ain't that great a steel welder, and I'm worse with aluminum, so the welds look like something Heidi left behind...Ha! But, it should work OK. I drilled an extra axle hole about 1 1/4" above the other. The upper hole is to use in the event you decide you'd like larger diameter wheels. Larger diameter is easier to roll over rough terrain. An 8" wheel, in the upper axle hole, keeps all the geometry the same. I think you'll like it, once you get used to the ugly welds...LOL Jim