Modded gpx settings

[Joeboy]

Gday prospectors,

What settings have you found on your modded 45 or 5k are working best for you,
In your situation. I read woody's article on a Nth Qld prospector with his modded gpx5000 running in fine gold, with factory gain set at 1, stabiliser at 1 and variable front end gain set to max. From what I read the increase in depth was stellar.

 I'm about to get my 45 modded and i would appreciate any input you would like to share with us.

Cheers, Joeboy.

[BigFoot]

Hi Joeboy,
I have had good results running my 5000 in fine gold, rx gain 1, stabiliser 1, front end gain a quarter turn from max and variable frequency 229 with the coiltek 11" elite. picked up 18 bits ranging from .07 to 2.3g on ground a 7000 had been over. I find i can run the coil in contact with the ground and the machine runs extremly stable. My mates 7000 cannot run stable that close to the ground so any depth advantage me may have is lost. Still have not worked out best settings for larger gold with low variable frequency numbers.
Cheers Bigfoot

[Joeboy]

Hi Bigfoot thanks, that's interesting that you were using the 11" elite and cleaning up after the Zed that's cool. I was just contemplating today which of the smaller coils to pick up, the 12 evo or 11 elite. I had the 14 elite on my standard 5k before I had to sell it, and it was great coil using fine gold.

 Ive got a small patch I've found with deep ground. Some of the bigger bits i've been picking up are 1 and 2 ounce bits and almost out out reach on the elite using in fine gold. So I thought I'd try normal timings on the elite get those deeper ones. But it was almost impossible to use, very noisy. Choking the 5k didn't do it any justice either,  It's just something I've noticed with these new coils using normal timings where I detect.

Thanks for sharing your settings Bigfoot, sounds good.

Cheers, Joeboy

[Joeboy]

Gday

Has anyone found good settings over deep hot ground with
Their new mods? Ie: factory gain @ 1 stabiliser @ 1 with variable gain set high.
Anyone done this but with variable frequency set in the low numbers chasing bigger
Bits! Or Maybe an increase with stabiliser... If ground conditions permitting.

[ronjeanosborne]

Hi joeboy, iam going to tibooburra mid may be hunting big gold with these sets on 14 inch carbon coil it runs very quiet as long as you dont touch the groung so i have some trial to do, i let you know when i get back first week in june, Ron.

[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

[shepcal@sti.net]

Joeboy, curious if you got your 4500 modded yet and made your movie for setting up. I just got my modded 4500 back today.
hurahhhhhhhh! Now have to figure out how to set up and use proficiently. I am using a new NF 12” round mono EVO coil. I set up according to brief instructions on ‘Latest GPX Upgrades Aug 2016’ to the letter. Front new knob half way. Front is set mono, fixed, general and normal. Set the back to
Man tune 120
Very slow
Gain 5
Audio normal
Stabilizer 10 target
Volume 8
Response normal


I’m going to consider the 12”, medium size and am looking for medium size nuggets. SOOO- I want to set my manual frequency on the LCD at say 160 or 170? and then adjust the new knob on front to smooth out? Or do I adjust LCD gain up then new knob to fine tune smoothness? I guess what I’m asking is the order of adjustments.

I will try gain at 1 and stabilizer at 1

Thanks, Shep

[Joeboy]

Gday Shep, be good to hear how you go with your 45 and settings etc... my 45 hasn't been modded just yet. Unfortunately i haven't been back out,  I've had to put a few things on hold for a while caring for a family member. Really looking forward to getting back out for a swing tho, don't think i can handle these withdrawals much longer getting the shakes and shit.
Hey just a quick question for ya about these new coils.
There was one thing i noticed up here in FNQ on really hot days my 14 elite really plays up big time. In the middle of the day i cant use it at all, and need to switch back to my older 14 mono than no problems at all! Just curious to hear if you've encountered any issues with heat swamping your evo coils at all?
Cheers Joe,
And good luck on your next trip.

[shepcal@sti.net]

my Evo is brand new and not dirty yet, but soon!

[woody]

Yesterday i went out to the Talbot test site to carry out some testing on the latest upgrade for the gpx and gp detectors. The new upgrades were tested with a NF 17 x 11 mono advantage coil.  Matt from Ballarat was doing the testing.  0.014 gram could be detected at 6-7 inches in hot ground, this is outstanding as the standard 4500 cannot hear the target. We then tested the 3 oz slug in the 22 inch hole, the target was still detectable at 8 inches above the ground. The most noticable difference was the extra sensitivity and huge reduction in ground noise. We did all our testing in normal mode so the testing applies to any gp detector as well. I rarely make comment about coils but the evolution coil that we swapped for some tests was absolutely outstanding with the variable input gain on the upgraded detector, the 12 inch evolution coil ,   although a tad noisier was pulling the targets as good as the 17 x 11 but also could hear the 2 crushed aliminium cans in the bottom hole, this is around 1.5 meters deep.

The coiltek elite may be as good but i did not have one to test, if i do not have it i cannot test it. But the 12" evolution coil imho is a must have coil.

[Joeboy]

Gees thats got me thinking.... alloy cans been picked up at 1.5 m, you'd think a big flat piece of gold of similar size would also be detected at that depth. Like that monster bit found recently by that very lucky chap!
 What about the detech dd 15" ultimate spiral anyone got one on their fully modded gpx? One would think with a very quite machine maybe even sharp might be an option with the new 15 dd.
Anyways i'm gunna buy one because they seem to be very good coil even when compared to the new evo/elite mono colis, also to see if it handles real hot days better than 14 elite which hates hot weather to say the least.