Carl, what kind of detector will detect small flakes of gold at 300KHZ?

[Randy Seden]

I've been looking at the Falcon MD-10 hand held detector which is a 300KHz unit with a 1"dia coil that is able to detect small flakes of gold at 1-2". I would like to build a similar unit and need your advice as to what kind of detector would do the job. IB,Phase,TR? I primarily drywash for gold in the High Mojave Desert in the El Paso Mtns. and would save having to pan.Thanks for your help.

Randy Seden

[Carl]

Re: Carl, what kind of detector will detect small flakes of gold at 300KHZ?

Rate sounds way too high for a PI, so my guess is a type of phase detector. Probably does not have inductively balanced coils though.

Where have you seen this? How much?

- Carl

[Randy Seden]

Re: Carl, what kind of detector will detect small flakes of gold at 300KHZ?

Carl,

Goto the Kellyco Detectors page and click on Falcon Gold Probes and you can read the specs. and maybe determine what kind of method their using. Sure appreciate your help as I'm saving my cash for the book "The 8051 Microcontroller and Embedded Systems" by Muhammed Mazidi which is going to set me back $90. The book is written by a teacher at the DeVry Institute of Technology in Dallas. I'm looking forward to getting a better handle on assembly programming to try an FFT routine and some low end audio DSP using the 8051 Evauluation board.
Randy Seden-WD6ELU



Kellyco Metal detectors page

[Eric Foster]

Re: Carl, what kind of detector will detect small flakes of gold at 300KHZ?

Highest pulse rate I have used for a PI is 100 kps (kilo pulses per sec.) A simple probe of this sensitivity would definitely not be PI. May be loaded oscillator type?

Eric.

[Unregistered]

pin point detector

Have you tried converting a ryobi stud and PIPE finder? 36.00 Lowes, Home Depot. It operates at around 300khz. Just take it apart, take the coil out(hot air gun, 4 wires) and install in a narrow plastic pipe. Make cable about 3 to 4 ft long that comes out of the top of the unit. Hot glue everything up, keeping the coil as close as possible to the end of the probe. One end of the coil is more sensitive than the other. You might install a sensitivity pot on the side that you can get to.(replace the small metal trim pot behind the tiny door that wants to fall out). The other pot is for wood sensitivity.I've made 5 of these so far. The first one, I melted the blue plastic case with the heat gun, so be careful. I haven't seen it go off on flakes, but it goes off on the tiny pickers we get in our dry washers here in New Mexico. Make sure you select "deep metal mode", wait for the calibrate "beep" and your ready. [email protected].

[walbridge1973]

You would be better off purchasing "Inside the Metal Detector" found on this site. It is a great book with projects and in depth knowledge on all types of deter systems. You can even download board prints to send off to be made dirk cheap. Then just plug and solder your own detector.

[homefire]

Here Ya Go.

[chemelec]

I Re-Drew this so it is easier to see.

[chemelec]

Corrections on Schematic.