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Modded gpx settings

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Joeboy:
Hi ronjeanosborne

Good on ya for getting involved on this thread, will be keen to know how you go!
I will be heading out my self early May to a rich little patch I found with real deep ground, where I've picked up multi ounce bits. I'll be swinging a brand new 4500 using the new 18" mono elite. I'll be making a video of my finds and what settings used. When I get back I'll be sending my 45 down to Woody for full upgrades than I'm back out to my patch to work over it again with the new mods. Also be making a video after upgrades once I understand how the get the best out of the newly modded 45.

Feel free anyone to give advice on these new mods

Joeboy

dover1123:
Evening all
After a weekend out and about I'm beginning to doubt my ability, my settings, and my sanity!

I've got the mods pre variable frequency update.

I found a screaming piece of rust (1mm x 3mm) on the surface early in the day. After finding a couple of .22 cases and the beloved boot tacks also on the surface without so much as a whoo hoo, I got curious as to the depth performance of my detector.

After burying the rust ~15cm down I began to test.
#1
Fine Gold / Sens Smooth / Sens Extra
Stabiliser:1
Rx gain: 1
Front end gain: Almost full
New timings: S / M / D
Result: Not a peep  :-[

#2
Normal
Stabiliser:1
Rx gain: 1
Front end gain: 1/2 to 3/4
Result: Heaps of background, but huge response. >:(

Tried with both Coiltek 14"x9" Gold Stalker mono  and 14"" Coiltek elite round mono (camo).

Some help / suggestions / humorous banter would be appreciated!

shepcal@sti.net:
I have a 4500, Woody modified years ago. Wonder if someone could post a pic of newest mod on detector? Also is there an instruction sheet for the new mods anywhere? I've read all posted info on Detectormods product page.
Thanks, Shep

woody:
Be careful on cranking the gain and frequency on fine gold, every detector before the gpx5000 have an initial input gain set at 47 times, that is the inverting opamp input is set to ground via a 10 ohm resistor and the feedback resistor is 470 ohms.  This is a gain of 47. The gpx5000 has the input gaiin feedback resistor set at 330 ohms and this sets the gain at 33 times.  The reason is that fine gold is just like enhance but the reciever is turned on faster and depending on coil capacitance and residual ground signal the amount of signal is onerloading the the voltage level detection circuitry.  Thus cranking up the gain and making the frequency higher will make the detector go deaf in fine gold.  The trick is to set the manual frequency to 120 and gain to 5 on the front dial. The coil capacitance issue really shows up when using older coils that did not use litz wire and the DD coils are also high capacitance nightmares.   Cranking everthing up is like driving a powerful v8 in the wet, take it easy on the power or you will just spinning the wheels.

Buffalochip:
A couple of days ago, after a long dry spell, I picked up two fly turds. The smallest, .05g, the sdc 2300 could not hear. The other, .11g was audible with the 2300. I
I'm using the 5k modded last November with full mods.
The settings I used are:
Front end gain = 8
Special = fine gold
Manual tune =200
Rx gain = 5
Audio = normal or boost
Motion = v slow
Stabilizer = 8
I am in central Arizona with a lot of hot rocks. Most of which the 5k ignored.
Coil = Nugget Finder, SADIE

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