Show all posts by user
This Open Forum is now DISABLE to new posts due to the "Phorum" Forum Software used for this forum being generally obsolete and basically no longer supported. Recently, the server that hosts this website upgraded to MySQL version 8.0.36 and Phorum 5.2.23 is not compatible with MySQL version 8.0.36. This Phorum based Discussion Forum will still be available for viewing and reference but is no longer accepting new postings and will be READ ONLY. To visit the NEW forum, CLICK HERE! Please note that those wishing to use the NEW Discussion Forum will have to re-sign up. Due to encryption of passwords, I cannot transfer users from the Phorum platform to the new forum platform. I am sorry for all the inconveniences. This Phorum based discussion forum will still be here for reference and veiwing, but will be closed for further posts.
This forum is currently read only. You can not log in or make any changes. This is a temporary situation.
So Part 3 describes this:
Two notes:
1) IQ still uses square waveforms which theoretically transmits an infinite number of frequencies when described in the (mathematical) frequency domain, where the software does all it’s calculations. Of course the higher harmonics have decreasing amplitude but they are there nonetheless, just like we see in BBS and FBS.
2) Both graphs show ident
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
Wow, never knew one existed. Power-on with a magnet!
For those interested in computational speed (I am not), the iPhone 7 runs ~300GFLOPS...
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
Quoterustic charmBearing this in mind, would it not be painfully obvious that in order to obtain the 'low cost, high efficiency' & still be competitive, one would have to consider off-shore manufacturing? Is it not exactly those principles that have western corporations scampering to China?
It really depends on the volume. IPhone-like? Yes. Metal detectors? Probably not. The
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
QuoteGeotechIf I could simply crank up the internal voltages and make noise disappear, I'd do it in a heartbeat.
So we come full circle and hit the shrinking silicon junction & lower breakdown voltages...
I see a continued trend to digitize signals in the coil, not just coil ID but the ground response signal and accelerator data too. The Deus model will become "the model"
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
Tom, do you still have a load of your highly mineralized dirt to test detectors? I’m guessing the EQ might be no better than many other detectors in your sand but may excel in bad dirt.
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
QuoteGeotechIf you have a perception that modern detectors are noisier than older designs, it's more likely because the older designs were just less sensitive.
Maybe we need to define ‘older.’ The CZ-6 launched more than 25 years ago, yet I consider that platform roughly equally sensitive compared to anything built to date using VLF, BBS or FBS technology. And I’ve used the CZ-3D in plac
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
So we know that the design of the CTX coils were different than previous ML coils. Do we know if Equinox coils offer a different hardware design from what we’ve seen in the past?
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
QuoteGeotechQuotego-rebelsNew detectors are more susceptible to EMI because their power consumption is lower. Older analog units are relatively power hungry and, by definition, less EMI susceptible.
I'd like to know whose definition determined this. It's not even wrong.
It’s not even wrong? ??? (And, of course, circuit design makes a huge difference.)
If I’m pushing bigger vo
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
QuoteGeotechQuotego-rebelsSo why put a preamp circuit in the coil? Either you pick up noise (eddies) in the added circuitry added to the coil or you pick up noise within the low voltage signal going up the coil wire.
Probably in almost all cases the preamp in the coil is a net benefit.
QuoteGeotechPutting the preamp in the coil helps with noise a little bit, in that the analog signal runni
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
It’s coming. The key here the development of cheap, tiny silicon chips capable of encoding and decoding laser signals sent via fiber optics. Today, when data arrives at a gate via a fiber optic connection it has to be moved from a separate photonic device to an electronic circuit. We need new systems where everything works in silicon. Prototype systems built today can carry data at a rate of 5
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
QuoteDaniel TnThere were only like 36,100 of them made, and it is generally thought that only 1 to 2 % of those are known to exist today.
That’s about right. Estimates are that ~500 Chain Cents are in collector’s hands today.
The Early American Coppers society did a rigorous statistical analysis on the survival rates of the various large cent types... Flowing Hairs, Liberty Caps, Draped Bus
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
QuoteGeotechWell, not really. Putting the preamp in the coil helps with noise a little bit, in that the analog signal running up the cable has more amplitude... In general, the more circuitry you put in the coil the more susceptible it is to potential ground noise. Circuits contain metal, and extraneous metal in a coil creates secondary eddies that interact with ground mineralization. It's s
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
QuoteBadger in NHOne thing I'm hoping is that if Minelab was smart, they would have planned all along to release the Equinox one week before the published release date.
It’s interesting to compare how other industries launch new products. Apple gives us a sale date and a few functional details but little else. There are no pictures... no videos. Car companies give up nothing before a ne
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
M/L may use an accelerometer to determine direction of coil motion and coil speed. They may apply different software algorithms to the signal based on coil acceleration/speed, both of which may be inferred from an accelerator, knowing that the signal amplitude/phase/shape (?) is dependent upon coil acceleration/speed.
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
Chain Cents are one of the "Holy Grails" in the numismatic world, along with Pine Tree shillings, SVDBs and 1955 Double Die cents, all coins readily obtainable today.
Below is one of the cheapest Chain Cents recently sold at auction, selling for $1528 last January. It’s quite a dog.
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
I’m not certain what, if any A/D conversion happens within a CTX coil. I understand that the coils have a pre-amp, an accelerometer, and a microcontroller to identify the coil and provide ‘security’ to prevent use of aftermarket coils.
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
It’s not just damage; it’s the creation of spurious signals. From my link:
I doubt many detectors are permanently damaged by EMI, no matter where they hunt. New detectors are more susceptible to EMI because their power consumption is lower. Older analog units are relatively power hungry and, by definition, less EMI susceptible.
Of course, the faster the A/D conversion, the more softw
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
Modern devices use higher frequency (more computations) and lower power (efficiency) and EMI now superimposes a relatively larger noise signal on the desirable circuit. More:
And obviously, digitizing a weak analog signal that contains a relatively high error as a resultant from external EMI, or less than perfect circuit design, will only produce an erroneous digital output.
Does anyone
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
Chapin is near the transitional zone separating the high mineralized clay earth of the Upstate from the sandy areas further south. So your particular site may or may not be difficult to detect.
The one positive thing is that coins tend to sink more slowly in the clay soil. I’ve found many 100+ year old coins in the 3-4" range in the Upstate where I live.
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
Just wondering... I’m assuming the owner is limiting your time... why would the property owner limit the time to 1hr, vs 2hr or an afternoon?
Still, it’s an interesting “what-if...”
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
Quote“diggers”you will be able to talk to your fridge and vacuum cleaner
Will be?
I yelled some obscenity at my frig last week when I saw I was out of beer...
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum
Quotejak135I spend a lot less on Metal Detecting than I do on golf
Same here.
I have a yearly $500-$1000 annual budget for golf equipment and gadgets, not counting greens fees which certainly exceed that amount. Don’t ask me how many shafts I have for my Taylormade M1 driver.
It’s just another hobby. Plus, it’s that much less eventually going to my daughter-in-law...
by
go-rebels
-
Thomas Dankowski Metal Detecting Forum