24 x 12 ufo troubles

well i had what i thought was a great 2 hrs tekting thismorning using a coiltek 24 x 12 ufo mono (first time really using it). the thing was smooth as and humming along nicely. after 2hrs i thought it was odd that i hadnt had any signals so i put my pick near the coil and it didnt make a sound till it came to about 4"!!! last week i used this coil in a trashy area and only gridding a small area. i couldnt dig a hole with the pick anywhere near the coil or it would scream.
has this happened to anyone else before? and what can be done? lucky i ran into a friend and we hooked it up to his machine and had the same trouble. almost 0 sensitivity. tried all settings etc and nothing. am running a gp3000 btw. last week this coil was finding minute flakes of rust.... whats wrong??????

Hi Corydale I was going to ask you if maybe the cancel switch may have been knocked but when you said you tried on your mates machine I am not sure any more I would get in touch with coiltek boys and see what they recon it could be.
Cheers
Mike.

Gday

I did have a similar thing happen to me with a coiltek 11" dd pro coil, I had used it on and off earlier in the trip, but walked around for several hours with it on that particular day, it was only when returning to where we had parked the cars, when I waved it over a small length of electrical wire that was laying on the ground, some copper strands could easily be seen protruding from it, but it gave no response at all.

I did the same thing as you and waved the pick near it but there was barely a signal, I checked all the obvious things like the cable, switches etc but everything was ok, I was really annoyed that I had wasted the best part of the day walking around with it, but of course there is no way of knowing exactly when it had failed.

Sending it back to coiltek as it was still under warranty I was sent a new coil to replace it, as far as I know it was a wire break where the lead goes into the coil housing, to confirm this you may be able to have the detector on and then while having a metallic object near the coil, hold the lead close to where it goes into the coil body and very slowly move it around and from side to side, if you suddenly get a response then you have found the problem, if you get nothing there then I would remove the cover from the pin plug and check to see if all the wires are still soldered, you could possibly have a dry solder joint there as well, if nothing is visible then you are better off sending it in to coiltek than trying to go any further with it yourself.

cheers

stayyerAU

thanks mate,
ill give that test a try. im not in the least bit technically able to do soldering or even know what to look for so i might just see if coiltek can fix it. its 2nd hand so no warrenty.......
cheers
cory

I cant imagine wandering around for even as much as a quarter hour without signal...if I see a rusty old tin I bip it...if I see a slither of a rusty anything I bip it....even old innerspring beds you find out in the scrub for some reason...I bip them and what a sound they give.. I would have thought all this was standard fare for all detectorists?..or am I wrong?....Hoo Roo

normally ide be the same but this is one of our very worked out thrashed sites. all the junk has already been found. its a miracle i found a shotgun pellet with the DD later in the day.

Hi Stayer, you do know that a bit of multi strand electric wire won't give much of a signal, if any on most coils and PI detectors? Try it out and see.

Cheers, Jim

it sure gives a honking sound on my 3000......

HMMM I guess it depends on the wire. I have run my coil over a bit of multi strand wire on more than one occasion and had not signal. Yet it will easily find a .1 bit of gold.

And when can you run your detector over a 10c coin and get no signal? Answer: When you turn it into filings, even glued together the detector won't see it. And most detectors have trouble with a fine silver or gold chain.

Cheers, Jim

Thats the time to use the 17 - 18000 Jim I am sure you know.

I'm not sure , but I think it's a bad idea to induce a short on a coil.

Dose not the OM warn, not to unplug the coil with the tector running?


Best thing may be to send it off for testing @ Coiltek.

Buy a digital multimeter, put it on the lowest ohm's range,
with a probe in pin1, put the other probe in pins 2.3.4
take the probe out of pin 1 and put it in pin 5 then
check pins 2,3 and 4, If you get the same reading each time
you should be good to go.

If you get no reading on a pin you have a problem in the coil
or plug.

BTW. the above is for a mono coil, DD's are different.

inhere,
thanks mate thats a great diagnostic test. i think a mate of mine has a multimeter i can use. i just hope the coil is not buggered. i only got it a few weeks ago from a member of this forum.

g'day corydale, you can buy them on ebay or even dick smith's
for about $15 mate, handy to have around for batteries etc.

They come with a little book to assist you, if you are not sure
of what you are doing.

granite2 wrote:Hi Stayer, you do know that a bit of multi strand electric wire won't give much of a signal, if any on most coils and PI detectors? Try it out and see.

Cheers, Jim

Gday Jim

Yeah I know what your saying but there was no response at all, even picking it up and giving it a rub against the coil did zip, it did respond to my pick though.

cheers

stayyerAU

larry303 wrote:I cant imagine wandering around for even as much as a quarter hour without signal...if I see a rusty old tin I bip it...if I see a slither of a rusty anything I bip it....even old innerspring beds you find out in the scrub for some reason...I bip them and what a sound they give.. I would have thought all this was standard fare for all detectorists?..or am I wrong?....Hoo Roo

Gday

The area I was working is highly trashed in some spots and I guess there would have been ample signals and a lot of it is visible, but the open areas of this place yield the odd piece of gold but little else so you can go for some time without getting a beep, I do the same thing as you when it is too quiet and usually wave the pick near the coil to see if it working but in this case the coil would only respond to large ferrous objects.

It coil would not respond to anything small, of course I also tested it on small nuggets when I realised that there was a problem with it, also when it was sent to coiltek it was replaced with a new one so there must have been some issue with it that was not worth fixing, or it was simply quicker to get a coil back to me.

The point I am making I guess is that it just failed and I dont know when it stopped working properly, it might have been two hours before, or ten minutes before, who knows, it might have been due to it snagging on something or whatever?

Lesson learn though so part of my routine when I have finished cleaning the coils after a trip is to give them a quick test out on the bench before storing them away.

cheers

stayyerAU

G'Day

When I am detecting, every now and then I swipe it across my sandshoes. The eyelets are aluminium (I suppose) and give a beaut signal, enough to bring the missus running to dig the "nugget"


That was with the 3500 so maybe I will have to change my boots with the 5000. Maybe rubber thongs will be the go So far, the 5000 doesn't seem to notice the eyelets in my sandshoes.


Waz

inhere-
i got a wee multimeter today and did as you instructed. got the same reading on all pin holes- 1.4 (probe in 1, other probe testing 2,3,4 then probe in 5 and the other testing 2,3,4.) does this mean is buggered then??? coiltek says because its one of the old epoxy filled ones it cant be fixed......

No corydale , that means the coil should be OK.
What reading did you get?

the reading was 1.4
im not sure what that means. i had the meter set to the lowest on the ohms as you said.
i did notice something odd later though. i plugged the coil on and turned it on inside and the threshold was smooth, no interference, which i thought was odd. i did some air tests and it would give me a weak signal at about 30cm on a big chunk of old steel. but when i tried an 8grm gold nugget you could almost touch the coil and it would only give a weak signal. i then noticed i had it on the sensative setting. i switched it to normal and then it went crazy with interferance. i had been running the coil on deep and sensative in the field. can you not use the sensative setting with a big mono???
not sure whats what now....

G;day corydale, all the tests that I have done (on GP's), I have had better results using normal/deep
rather than sen/deep. I don't have a 24" UFO but I have a 17" UFO that I will drag out after I finish this coffee
and see what it reads, I'll get back later.

PS. QldSandy has a test between a 3500 and a 4000 on his gold & coin forum that you might have a look at,
they did a test with a 24" UFO, just do a search.

Ok corydale, my 17"UFO reads .9. The coil should be fine,
I think your problems are elsewhere.

Let us know how it ends up.

now im confused....
so what could be the trouble then? the machine performes brilliantly with the standard DD coil. great depth and senitivity.

I can't tell from here corydale!

I would take the detector out where there is no interference, checking everything one at a time.
eg; just in normal, with and without sensitive etc and make sure that cancel is off.

Try again with another coil, If you only have a DD coil try it in the mono setting?????

As I said it appears the coil should work, anything wrong with the coil should have shown up
in that test.

thanks mate,
ill try that.
my DD works a treat in mono mode- super sensative and surprisingly less noisy than the DD mode.
i might try an catch up with a mate that has an extreme and try the coil on his and see what happens....

granite2 wrote:Hi Stayer, you do know that a bit of multi strand electric wire won't give much of a signal, if any on most coils and PI detectors? Try it out and see.

Cheers, Jim

Hi Corydale, sounds like you have maybe a setting problem mate. My 24 x12 ufo will almost blow my eardrums out if I even wave it over a paper staple, which there are many many thousands out there. I'm sure some saddist has taken a stapler out in the field and has fired off staples in all directions all over this country, and must have an account with Office Works or something. As a couple of mates of mine will testify, I have found literally thousands of these in the West, spending hours digging them over many weeks. My old Extreme combined with this coil is just too sensitive. No need to switch over to Sensitive Mode in a lot of areas, unless, the soil is quiet, and the gold is small. As some of the "Lads" have stated, if all seems too quiet, wave the coil over your "Steel Capped Boots" every now and then to make sure you've still got power. It saves a lot of walking for nothing more than to get fit. Cheers, Cashman.

i did some tests today. i wasnt able to get to a completely interference free zone, but on normal on deep i was able to get the threshold to behave enough to hear targets. the coil went brilliantly in normal mode pikcing up many unknowen targets in the area- i was able to wave the coil near on 2 feet above some big signals. as soon as it was put into sensative the threshold went totaly stable and there was almost 0 reaction to targets more than 1".
so i went into the brisbane gold shop today and we tried an experiment. we put the ufo on and turned the detector on in the shop in normal mode. as expected the noise was horrible interference. when switched to sensative it was quiet as. the DD coil was erratic on all but cancell mode as expected. then we plugged in a brand new mono coil off the shelf and when set to normal and sensative both gave the expected squeel of interferance.
so it seems that when you have my ufo set on sensative, something is going wrong....... has anyone come across this before? and if so can it be fixed. i will endevour to get to an interference free zone soon and try the coil on normal and see how we go.

OK corydale, i'm not sure what changes when you go into sensitive, there can be reasons why
that sized coil could work OK in normal or deep but not in sensitive
but I dont want to go into that here until I find out what goes on when you set sensitive..

Is it such a problem? With that sized coil I would use it in normal/deep anyway.

too right mate. i think it might be reserved for that purpose in future. thanks all for the advise.