61
Information on the new developments / Re: Z mods
« on: September 19, 2017, 05:14:25 pm »
Yes, see post on GPZ-7000
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62
Information on the new developments / GPZ7000 upgrades...yes yes yes
« on: September 19, 2017, 05:13:27 pm »
We can now upgrade the GPZ-7000 , greater depth, better small gold performance and more stabile and quiet.
(Pity we cannot make it lighter)
Currently carrying out tests on a variety of ground.
(Pity we cannot make it lighter)
Currently carrying out tests on a variety of ground.
63
General Discussion / Re: modded GP3000 settings
« on: September 18, 2017, 08:49:57 pm »
It is good to hear that you are doing well with the mods, I am always working on mods, t the moment doing some experimental upgrades to the GPZ-7000 and see how it pans out. I have an article coming out in GGT in regards to detector technology. With the GP if it has variable frequency and variable gain it should be kicking goals for you. The latest is changing the components in the input stage to get lower losses and less noise.
64
Information on the new developments / Re: Major discovery applicable to all SD GP and GPX series detectors.
« on: September 12, 2017, 12:54:48 am »
Around 10 years ago I wrote an article on geotech about installing variable damping resistance into the SD2000 or any P.I detector, setting the damping to match the coil and to a degree the ground reactance can make a substantial improvement to the early time detection of small signals. It would not be too dificult to incorporate an automatic variable damping system into a P.I to critically match the coil characteristics when using different modes of timing to cover various decay profiles. It would be even better to use dual damping on different pulse lengths to optimize the decay on both the high and low voltage tx pulses to better match the the system to the coils that all differ in decay due to manufacturing variations.
65
Information on the new developments / Re: Major discovery applicable to all SD GP and GPX series detectors.
« on: September 07, 2017, 08:10:45 am »
Sensitivity and low noise are dictated by where the low noise components and gain is set in the signal gain block. Firstly you get maximum depth and sensitivity the most important thing is to remove resistive loss before the first amplifier, this includes the resistive characteristics of the input mosfets. With a coil resistance of 0.5 ohm the resistance of the input fets at around 5 ohms eats up a fair amount of the signal that is available to be amplified. Other losses are the capacitance of the coil, the cable and capacitance of the input components that reduce the initial slew rate of the detector to be able to recover fast decay target signals. To recover all available signals the initial input stage should have low noise and adjustable gain to suit the ground conditions. The set gain of 33 gpx5000 or 47 gp series and gpx4500 is too much or too little depending on ground decay characteristics. The back gain takes place after multiplexing and as far as i can tell with the existing block gain there is signal loss and trying to boost it greatly increases the overall system noise and target signals can be swamped by the noise. The front end gain sets the input signal at a level that produces optimal signal levels in respect to ground noise the get an improved signal to noise ratio and get the most out of the detector. Many variables need to worked out properly and not just increase the gain, sometimes less is more and sometimes it is the opposite. I also found excess capacitance can cause an offset in the ground balance and thus needs to be greatly reduced as to get better ground balance.
66
General Discussion / Re: new mod settings on 4500
« on: August 07, 2017, 10:10:02 am »
Total overkill , but if its cheap...
67
General Discussion / Re: Upgrades changed away from the 3 way switch
« on: August 07, 2017, 07:27:19 am »
That change was around Two years ago.
68
General Discussion / Re: new mod settings on 4500
« on: August 06, 2017, 10:38:36 pm »
You need the inductance to measure down into uh. Not mh.
69
General Discussion / Re: What size/weight is considered to be a small nugget ?
« on: August 05, 2017, 03:50:10 pm »
That is very difficult as most people have their own idea, small nugget is up to 5 grams, some think a large nugget is 1 oz , some think 10 oz is large. Years ago grammers would of been referred to as tiny, 1 oz would be ho hum and the multi thousand oz nuggets as large. Its all perspective.
70
Information on the new developments / Re: Major discovery applicable to all SD GP and GPX series detectors.
« on: August 05, 2017, 09:44:09 am »
On my 4500 i run my back gain on 5 but on quiet ground i crank it to 8
71
Information on the new developments / Re: Major discovery applicable to all SD GP and GPX series detectors.
« on: August 05, 2017, 07:13:09 am »
It depends on the ground as to how to set the gain, bur as a general rule I crank up the front gain and tame the ground in the back menu gain setting. I use normal timings if the ground allows.
72
Information on the new developments / Re: Major discovery applicable to all SD GP and GPX series detectors.
« on: August 05, 2017, 12:19:13 am »
We can increase the gain of the detector that gives more depth and sensitivity at the same time...
73
General Discussion / Re: Detector Coil
« on: August 01, 2017, 01:02:55 am »
Hi Herb,
There are many video's on Youtube comparing those coils.
There are many video's on Youtube comparing those coils.
74
General Discussion / Re: new generation coils on gp series detectors
« on: August 01, 2017, 01:02:05 am »
It is good that everything is working well, I have been testing a lot of very new experimental upgrades and there is some big performance gains to be had match the coil impedance more accurately to the input stage, using a balanced input design I can just about get rid of most emi.
75
General Discussion / Re: modded GP3000 settings
« on: August 01, 2017, 12:58:11 am »
The 4500 is more advanced than the gp series and cannot lock up its own PLL as does the gp series.
Another thing is that I should be getting notifications on post on the forum but I do not get notified, if you do not get a response in a day send me an email
detectormods at gmail.com.
Another thing is that I should be getting notifications on post on the forum but I do not get notified, if you do not get a response in a day send me an email
detectormods at gmail.com.