A day at Mt Crawford - is my detector functioning correctly?

[TTKooAu]

I used to run a Whites V/sat up at Mt. Crawford, also 50 kHz and found it a handful, but that was with a concentric coil. Do you have a DD coil on the GMZ? If so sections of Watts Gully are not too bad mineralisation wise, but you may have better luck on the slope on the eastern side of the gully that heads towards snake gully. Lots of quartz here, and pretty mild.

Yeah, I have the DD, so that's a good start .
Not too sure which snake gully you are referring to. But I think I may head there Monday and have a swing around the Rocky Creek Rd / Watts Gully Road intersection. What could go wrong !

Thanks for the advice, appreciated.

Hi again Phasetech,

I pilfered your response to a previous post because I didn't want to hijack that topic.

I spent the Monday at Mt Crawford, it was the pick of the days weather-wise last week. I did the eastern side as you suggested, and searched by grid patterns from 9:00 AM until just after 1:30 PM. No gold detected, found 1 x .22 bullet, 2 metal cased .222 blanks and about 30 plastic cased .243 blanks. Maybe the army have run exercises there at some stage in the past. There was plenty of quartz around the area. A few bits of wire. I did think it odd that I found nothing smaller that the .22 bullet head and it did make me wonder if the GMZ is functioning properly? Being a no threshold machine, for the most part it is either signal or no signal, with no real distinction, the exceptions being if I go over a hairpin (double signal), chain (crackly signal) or a deeply buried 5c piece (an oddly different beep). From others reports on the GMZ, I gather it should be able to detect sub-grammers. I wonder if it is worth my while having it checked over?
Obviously though, I do have to walk over them to find them!
I was running a bit short of time in the afternoon, but I did a quick hoover with my crevice pump under a tree root in the creek that runs along Watts Gully Rd just north of Rocky Creek Rd, and panned out 3 specks of colour from a half cup of sample, so the day wasn't a total loss, plus half the joy is getting out of the office. I might head back their with my sluice in a week or so and see what I can find.

TT

 

[condor22]

Unless you have something smaller, use a sharp knife and pliers to cut a shotgun pellet size piece off the .22 bullet. Then try the detector on it where nothing interferes.
Lead is soft enough and sounds very similar to Gold. Small split lead sinkers cut in half are another option.

Don't be too disappointed at Mt. Crawford, it's a very small area, it's been hammered to death and trashy. I'm not saying there is no gold there, but given the tree planting and history it's very hard to find.

 

[Goldpick]

I don't think there is anything wrong with your detector, and you probably have to be more realistic with your expectations in such an area - there is still gold there, it is still being found, but it doesn't necessarily guarantee instant success, especially with what is considered as a starter gold detector. Also consider the fact that many other people have been over the same ground, with a miriad of vlf detectors either hosting the same ability or even more capable again (not to mention all the PI detectors as well).

Despite the GMZ running a high frequency, the more expensive vlf gold detectors tend to run an audible threshold, and for good reason, to hear very faint threshold rises/dropouts of very small or deep gold, plus with more adjustability to suit ground conditions. It is most likely that these type of signals will not be strong enough to break the internal threshold on the GMZ, hence mean you may be walking over good targets.

You have to be realstic regarding the capabilites of your chosen detector, and put yourself in the best setting to suit the detector, and that includes working spoil piles, around shafts, washouts, drains and areas where bedrock is near the surface vs gridding up half the fossicking area. I think that will simply lead to even more frustration, better off concentrating on the above areas. There are areas where the ground has been ripped for planting pine seedlings, this may expose some gold or specimens, but generally, looking in deeper ground with the GMZ probably won't be that productive, it's not really what it was designed for.

Possibly a way to get more depth and sensitivity out of them is to run the GB and sensitivity controls slightly hot, so it is not totally silent. This may cause some falsing, but may lead to better depth on targets that couldn't previously break threshold. Just a thought, maybe test that theory out with a few in ground test targets.

Probably not much point in doing air tests to see how sensitive it is to small stuff, we already know it is a sensitive detector. Best off to carry a small test nugget/lead shot with you out to the location, and test it in the ground to see what the real capabilites of the GMZ are (with real ground mineralisation). Then you can be confident of knowing what to listen for, how deep it can really go, and to know whether you will have a realistic chance of finding something in that area. Generally if you are finding small lead shot, then you should have a chance of finding something, so long as it is in suitable ground.

 

[Guest]

The GMZ is what it is and isn't real good at all in high mineralisation the best way to ground balance is turn the Gain all the way up' bob the coil up and down about 3" of the ground and start turning the ground reject up untill it stops false beeping, then turn the Gain down a little. Now this is as good as it gets dig only the true target signals most static half chirps are nothing but I have been fooled before! Now if you are still having trouble no doubt the ground is too hot and it will never work.
I'm happy to check it over for you but if it's still in warranty send it to goldsearch as dean would be happy to test it.

 

[PhaseTech]

I've never used a GMZ so can't really help with settings. I think you did really well in that area. Next time, bring up some lead shot or chopped up bits of lead, put them in the ground and play with your settings, see what gives you the loudest response while still not reacting to the ground.

 

[TTKooAu]

Thanks for your assessments guys, really appreciate it. I think what all 3 of you say makes good sense. I have some small lead shot and also some small link 9ct gold chain found in a tot lot. From your suggestions I am thinking of nipping off some part links of the chain, maybe squash / flatten them into irregular shapes and plant them in the terrain I am shooting. Also thanks for your advice on the gain and GB. Probably head back there in a week's time, so I'll let you know how I progressed.
TT

 

[TTKooAu]

Edit to above, thanks to all 4 of you

 

[TTKooAu]

Update.
I met up with Condor22 at Mt Crawford on Monday. We had a pleasant morning detecting up the eastern side of Watts Gully. Again no gold, but it was good to get some tips from him about my technique and the set-up of the lead to the control box. We also set up some small samples of lead shot and small gold to test the sensitivity.

It was a bit like David and Goliath, Condor22 was testing a new 8" on his 5000 and I was waving my GMZ around. Still I was able to see the limitations I am faced with.

I discovered two things.

1. I need more patience.

2. I want a 5000 :lol:

Condor22 took off at lunchtime, and I gave a new sluice I had made a run. I won't know the success of it until I pan off the concentrates over the weekend.

 

[condor22]

We're obviously still poor then !!

 

[loamer]

the 8" mono on a 5000 or 4500 will get as much small wheat sized gold as any other detector especially on highly mineralised ground and mullock heaps. the 5000 will probably win with the fine gold timing but running tests against the 4500/5000 both with 8" monos was a draw. there can be issues with small lead shot but thats the same with any detector- nice sweet sound. they are also very good on species, in my experience not as accurate as a VLF though running flat out on clear mullock or reef dumps. The major issue with the 8" round I have found is that the detector is way out of balance - not ground balance - just becomes very top heavy due to the small coil.

 

[TTKooAu]

We're obviously still poor then !!

Ha ha... as a church mouse.
thanks for our help on Monday.

 

[condor22]

the 8" mono on a 5000 or 4500 will get as much small wheat sized gold as any other detector especially on highly mineralised ground and mullock heaps. the 5000 will probably win with the fine gold timing but running tests against the 4500/5000 both with 8" monos was a draw. there can be issues with small lead shot but thats the same with any detector- nice sweet sound. they are also very good on species, in my experience not as accurate as a VLF though running flat out on clear mullock or reef dumps. The major issue with the 8" round I have found is that the detector is way out of balance - not ground balance - just becomes very top heavy due to the small coil.

Tell me about it. I have my bungy balanced for the 11" coil so the control box sits a little above the coil when hanging from my harness. I put the 8" on and the box was way down, so I couldn't let it go like I do with the 11".

There is a 266gr difference in weight. Might look at a non metallic counterweight I can put at the bottom of the shaft, being as I have a shaft for each coil it could stay there.

Next job on the to do list methinks.