Optix

Yes, it's called coil knock.

On 11/30/2023 at 11:07 AM, RickUK said:

I am fully aware that this is a very old post but just treated myself to a GPX4500 that has come along after only being used once,i have purchased this at well under 1/2 price and only been used just the once.The guy is selling it as he cannot master it and its been sitting gathering dust.

I have about 6-7 GPX coils from 6'' Mono upto 18'' Mono that i use on my TDI Pro with great success,so when this GPX 4500 came along i could not miss it,wont ever be used for nugget hunting as it's main use will be deep hoards hear in the UK,could not justify the GPX5000 which has fine gold timings for nugget hunting so went for the slightly lesser spec 4500.

Initially will be using the factory battery setup and then look at the various after market camcorder battery options as they are so much lighter and cheaper than the genuine factory battery.

Just hope that i have made a wise choice on this one,i pretty certain that i have as basically its only been used for a couple of hours so in totally mint condition.

I am interested in the camcorder battery upgrade you mentioned. Can you link me to an example? I'd appreciate it.

On 6/11/2022 at 7:22 PM, Aureous said:

 My ratio of gold to junk sits about 40:1!

40 gold to 1 junk? That's pretty good!

Check out the classified section, someone is selling a Nox 800 with two coils (11" and 6") and it still has over two years of warranty left on it.

I scrolled through a few others with the class 9 category, and the description changes a bit. Seems like they use a bunch of keywords that may or may not necessarily indicate the capabilities of the machine.

The Vanquish description is as follows:

Class 9: Metal detectors; Surveying apparatus and instruments; Oscillographs; Inductors (electricity); Probes for scientific purposes; Metal detectors for industrial or military purposes; Electromagnetic coils

From the brief description on the page:

Class 9: Detectors for electrically conducting materials, namely, metal detectors, metal detectors for industrial or military purposes, metal detectors for countermine purposes, metal detectors for consumer and recreational purposes, metal detectors for gold mining purposes, metal detectors for use in conjunction with software; metal detectors with mapping and/or global positioning system functionalities; electromagnetic coils for metal detectors.

Is that just a general description, or is it hinting at what this model might be capable of doing?

If you're worried about the ears breaking, you can try 3d printing a set of these:

https://www.thingiverse.com/thing:3949618

If you don't have a 3d printer handy, they are sold for pretty cheap in a lot of places online.

I know I can file a claim with ML to have them take care of it if they break, but my philosophy is "it's better to be proactive than reactive".

This might be something I need to get. It's been 100+ degrees here for over a month, so I've been sitting home 😞

Thanks for the tip!

A fun fact I learned some time ago is that $1 in quarters weighs the same as $1 in dimes (about 22.6g), so if you separate them from  your nickles and pennies, weigh them in grams and divide by 22.6 you can make a pretty accurate estimate on how much you have without counting them.

Do you use a tumbler to clean your clad, or is it unnecessary?

Do you ya'll sell your gold finds? Do you just go to a jeweler and sell it for scrap?

This is Volt. He's currently a year and a half. Haven't taken him detecting yet. Planning to take him when it cools off.

That is some great info there! So there is a lot of variation from coil to coil within a lineup. But does a statistically average coil of one brand outperform an average coil of the same size from another brand? Maybe one brand uses a different technique to make their loops better in general?

What is this "Coil Knock" you guys are talking about?

14 hours ago, Steve Herschbach said:

Like Mike said, small concentrics are great unless the ground is really nasty, then small DD. Small is the key in either case.

Fisher F70 control panel

Is there any real difference between an original Fisher 5" DD and an aftermarket 5" DD (e.g. NEL) for the same detector?

That's a very satisfying crunch!

On 1/5/2020 at 1:38 PM, Ronnie Williams said:

I have the Fisher F75+. If I have the discrim set at say 30, why do I sometimes get low VDI numbers like 6 or 7?

Have any luck resolving your issue?

On 12/2/2018 at 7:48 PM, Maltfoto said:

I don't used f70 on the beach. I use the f70 along with Whites Tdl for nugget hunting and gold prospecting.  

If I may ask, what coil do you use on the F70 for nugget hunting? Thanks.

Good video, thanks for sharing!

On 6/3/2020 at 8:20 AM, Steve Herschbach said:

Over time I am trying to recreate some of that lost content here, but on older models, especially posts by people no longer with us, it’s just lost and gone.

Thank you for doing this. It's always sad to see good, useful information get lost.

One of the biggest tragedies for the forums happened when photobucket went pay-to-play. A lot of pictorial DIY guides were lost.

I think it would be better if you posted all your findings in the same post instead of making one for each item.

Express is a higher end clothing line so I'm guessing it's probably a relatively modern button piece.

Great suggestions from everyone. I'm looking to buy a machine for my nephew to join me and my brother at the parks. I have an opportunity to buy a like new ACE 400 for $100. Should I spend a little more to get the simplex instead? Trying to keep it under $300 mark.

Thank you everyone for great feedback. I have a lot to learn about the machine and have plenty of other reading to do. I was able to purchase the missing pieces from the marketplace here and am ready to go hunting!

Hello, I am new to the forum. I have a Minelab GPX 4500 that I've inherited from my uncle so I'm trying to learn everything about it. It is missing a few pieces so I'm trying to get it into operational order. It is currently missing the battery, the power cable and the charger, and only has one 18x12" Coiltek Goldstalker mono coil.

Any tips/tricks/and suggestion will be appreciated since I don't know anything about the machine. Thank you.