Jonathan Porter

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Jonathan Porter last won the day on February 11

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About Jonathan Porter

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  • Location:
    Clermont, QLD, Australia
  • Gear Used:
    GPZ 7000

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  1. Bumping the coil hard is what causes the falsing, General is the worst culprit and will do it on the GPZ14" too if you knock it about in the same fashion. The weight of the GPZ19 is what is causing people to struggle if their harness is not set up properly to support the weight. I personally use a hipstick and remove the J struts and Snaffle bit. I also wrap the bungee around the handle just below the Quick Trak button and zip tie in place with the bungee wrap attachment point slightly above the balance point so the detector is weight biased toward the coil. The GPZ19 coil requires careful coil control to get maximum performance, if your knocking the coil to the point falsing is competing with target signals you need to try and improve your coil control. JP
  2. I do not recommend new users of the GPZ 7000 to use the 19" coil until they are proficient in the 14" and the detector in general. The falsing will be exacerbated by running too much Sensitivity and too high Target Volume, so settings do have a lot to do with it. General is the worst particularly if you roll the center of the coil over rocks, the 14" coil will do the same if treated the same way but is more manageable thanks to less weight and having a solid skid plate. I only use my GPZ19 coil with the solid NF skid plate for this very reason, I also place a 3 inch piece of soft foam each side of center of the coil to act as a buffer between the skid and coils base.
  3. Jen please put up the settings you are using with the GPZ 19 coil.......if you don't want them public then PM me so I can offer some advice. The GPZ19 can be a bit touch sensitive in some gold modes due to the potted design but it is manageable. JP
  4. Hi Steve, great thread as usual and very comprehensive. My first detector was a GT 16000 which was around the 6.3 Khz, back in those days there was a fair bit of decent sized gold still laying around for the lower freq VLF machines especially in conjunction with an auto GB. If you'll remember the GB PRO was way behind in numbers when we used the GBII on those patches in WA and required careful coil control in the super noisy variable ground to try and ping what was available, whereas the higher Freq GBII nailed piece after piece. In Australian soils I feel the High Freq VLF is a better option purely because the depth differences between the lower and higher frequencies are not that great due to the levels of mineralisation, yet the sensitivity gulf on small targets is massive; in other words depth suffers tremendously with VLF's in high mineralisation regardless of the frequency so you may as well target areas where the shallow little pieces are plentiful. If you want the deeper bigger pieces then get yourself a PI like the SDC to chase the deeper 1 tenth gram and bigger gold. The bench mark for any VLF detector in Australia to target gold regularly in competition with the PIs is high frequency and Auto Ground balance. Auto GB is a MUST for Australia and to this day the XT 17000 was the detector to beat for accessing all areas not just quiet ground types. I was not a huge fan of the XT 18000 and hated the Eureka Gold. The GBII holds its place for sheer sensitivity and ergonomics, in my opinion its taken 22 years for someone to take its crown here in Australia. If it is an all rounder type VLF machine in my opinion the GB PRO (and all its variants), AT GOLD and Xterra 705 are the go to bench mark machines. JP
  5. The key differences in how the GPZ sounds is down to the Audio Smoothing, operators are not used to having access to the low noise floor levels of the GPZ so can find the sound/volume of the GPZ very dominant. The key to using a low noise floor is understanding everything has more presence when Audio Smoothing is off, so because of that the Target Volume suddenly becomes a very powerful control right up there with the Sensitivity control. Target Volume has a huge impact on a persons perception of the detectors overall volume levels, because the noise floor is so low you have access to everything the detector is doing and seeing. This means there is a balancing act needed to get a clean audible smooth threshold with decent target signal volumes without distortion and jitteryness. The B&Z booster allows the operator to have a full range of Volume control of the GPZ without distortion because you are only ever amplifying the smooth audio of the detector assuming you have set it up correctly. So the key here is to keep the Target Volume levels as low as possible, in the case of speakers it needs to be no more than 8 when in combination with Audio Smoothing OFF, for headphones even less. The reason the Target Volume needs to be less is due to the B&Z booster needing to be above 1 1/2 to 2 on the Volume control Pot to avoid hiss noise, this means the detectors Volume needs to be lowered to allow a better range of Volume control on the booster. The B&Z through headphones has a secondary threshold like buzz which a lot of people like, getting the Volumes of the detector right makes this less intrusive. If your lucky enough to live in an area where you can use the Normal Ground Type modes then it is recommended you use even less Volume to allow for the added noise levels associated with those modes. Recommended GPZ7000/B&Z booster/Speaker/headphone settings. Audio Smoothing: OFF Target Volume: 6 to 8 (Twin Speakers), 4 to 8 Headphones Volume Limit: 8 (Twin Speakers), 8 or less for Headphones (Experiment with this dependent on your headphones) Threshold: 27 The advantages of the B&Z booster/speaker combo over the WM 12 speaker is two fold, firstly they are better quality speakers so they sound crisper to the ear and secondly the booster gives you much better control over the volume of the audio with minimal distortion, by being able to spread out the audio volume you get much better resolution on faint edge of detection range targets. JP
  6. Andyy are you using headphones or speakers? Sorry if you've stated that somewhere, I'm strapped for time so can't read everything in this thread. JP
  7. Hi Dave, early days on making too much public comment on the GoldMonster just yet other than what has already been said by Minelab. I can say it is a very nice VLF machine for ease of use and has surprising ability even in the hotter areas. Your country is perfect for a high frequency VLF detector and that's exactly what the GoldMonster 1000 is, a nicely done single frequency VLF machine. Your welcome to come down to Clermont and take mine for a spin when I get the OK to do so. JP
  8. Hi all, have been watching this thread but as Steve has said things are a bit busy. I will say though this type of discussion really makes my day job hard to bear. Maps believe it or not are my weak point, I'm a "shoot from the hip" type of guy so put me within a mineralised belt and I'll let my legs do the rest. However what Goldhound is hinting at is pretty much what my long time team members have been doing for years with an added twist, we use stream sediment data and soil sampling data in combination with geological maps etc. Obviously Geochem is only useful in areas where extensive historical sampling has been conducted so not so useful in Tiger country in the wilds of North QLD. The key is to find or highlight a possible target zone and to then get access to the area and then do the leg work along the strike, in the case of the Northern parts of Australia the streams and drainage's are your best friend and are usually your first port of call. Oh to be 20 years younger and 30 pounds lighter. The GPZ is made for this type green-fields of prospecting, not the weight but the tech. I can't complain though because I've found more than my fair share and had many adventures along the way. JP
  9. jasong, the key to burying targets is to walk around the general area familiarizing yourself with ground conditions and general detector behavior before coming in over the target, and to then be 100% honest with yourself on the question "would you have found that when you didn't know the target was there?" It is very easy to tweak a detector to give a "better" signal response on a "known" target and then go off with those settings with a false impression of actual real world performance. (I'm not saying your doing this BTW, just alerting forum readers of the potential pitfalls) The thing to understand about metal detectors is the detector has to convert the receive signal into an audio platform as a means of interface, that interface can be impacted upon by so many factors of which the major one is our brains uncanny ability to control the levels of perceived volume dependent on how loud continual exposure to the audio source is. As an example if you listen to a loud volume for long periods it will take your brain at least an hour or even longer to readjust to a lower volume level thereby giving the operator the false impression a target signal is weak when in actual fact it is the operators brain that is controlling the perceived volume levels. As an example after a long car journey you will notice you feel deaf when you finally reach your destination especially at night when all is quiet, this deafness is due to your brain adjusting the audio volume levels and taking a long time to re-adjust to the new noise levels without the road noise present, usually a good nights rest will correct this. Sound and the volume of sound has a very big impact on an operators ability to recognize an "edge of detection" signal response, in my experience increasing Volumes and Sensitivity too high will only really impact on the near to coil target and ground signal responses and could potentially mask or hide the fainter signals. My absolute aim is to keep ground signals and other non essential audio responses at a minimum whilst carefully listening for a disturbance in the receive winding feedback as the coil passes through the signal plume of a deep at "edge of detection" target, I always try to keep the volume variance resolution as wide as possible to fully tap into the nuance of the target signal. My 2 cents JP
  10. If you want to run Audio Smoothing OFF so you can tap into the full depth potential of the GPZ then do not adjust the other settings like Target Volume and Sensitivity too high for your given area. The Target Volume control in particular is the setting that makes the GPZ noisy, use it sparingly. JP
  11. A lot of GPZ features were just ported across from the CTX platform with the main focus during development of the GPZ 7000 being around ZVT tech which was incredibly time consuming and expensive. Hopefully in the future we will see improvements. I for one would love to be able to dump to an app on my mobile phone, it would be excellent if it could access maps in my smart phone that have already been downloaded regardless of phone signal. JP
  12. Hi Steve, I still use my inbuilt GPS and at times I also use the bread crumb trail. In the past if I've left the bread crumb trail on I've noticed a sluggishness to the menu selections which I've attributed with memory usage and as you have noticed sometimes you need to offload data once the memory becomes full. Perhaps a dedicated regime of data dumping before the memory gets too full should become a part of our work flow? I'm not saying for one second users should not use the inbuilt GPS but instead pay attention to detector behavior and offload your data periodically. I don't think the memory usage affects performance other than perhaps causing the GUI to slow down a little once memory resources start to approach the full mark. Keep in mind my role is to fine tooth comb these sorts of things, most people would most likely not even notice and call it nit picking. For perspective in terms of impact on your detecting, the GPS has a lot less of an impact than when the WM 12 audio drops out. Hope this helps clarify my meaning. JP
  13. The Nugget Finder 19" skid plates for the GPZ19 coil have been available here in Australia for some time now so should also be procurable through the US Nugget Finder dealer net work. The GPS on the GPZ7000 is in my opinion a resource hog, when I've used it (especially when using the bread crumb trails) I feel I can notice the general snappiness of the detectors menu controls becoming sluggish and overall audio to become chattery, as such I do not trust it to not meddle in other aspects of the detector like its on board Memory, Ferrite Balance algorithm, general GB duties and theTx and Rx of ZVT, as such I opt to turn it off. It's a personal decision most likely steeped in placebo but I'm always performance based when it comes to metal detecting, as such I choose not to use it. JP
  14. Thanks everyone for the birthday wishes it is truly appreciated. Had a quiet day here with family and friends, even managed to spend some time pondering when I can take some time off to head off detecting. JP
  15. Hi all, Severe was developed for ground that is "Highly Saturable". Saturation means when you couple the coil to the ground it causes a swamping like target signal that drowns out everything else, this swamping effect is determined by the height of the coil from the ground. The only way to deal with Saturation (GPX detectors do this too) is to lift the coil above the saturation point or go to a mode that is less aggressive. Generally the more saturable areas are also quite shallow so Severe was developed to allow the coil to be placed right on top of the ground in saturable soils without causing a large audio response, allowing shallow nuggets to stand out. Like all things there is a trade off, so Severe really pulls back on outright depth so should only ever be used in areas that are not deep. The GPZ 7000 is more prone to saturation than previous detectors in certain conditions so Severe was developed for that purpose. Quite often in WA Saturable soils are also salty so removing the Saturation signal can help a lot with identifying target responses. Severe is a variant of High Yield so has VERY good sensitivity to tiny gold. Out of interest SteveH I helped develop Severe only a few miles south of where we were camped all those years ago. JP