Coils for the QED

[Reg Wilson]

Over the last few days I have been out testing a 15" spiral wound X coil on the QED. To say I am impressed would be an understatement.
The only reason I am currently writing this report is because I forgot to put the detector on charge last night, so I am waiting until it is fully charged before venturing out again. The weather is pleasant at the moment and grass is very short. Other than a few bush flies, conditions are pretty much ideal.
So far I have found the 15" to be very stable with an excellent, positive signal response even on very small targets. Target depth is superior to any coil of similar size that I have yet used. The weight is up there a bit, but to be expected with the extra wiring. I may have to use a bungee if I intend to use it for extended periods as my busted wrist began to play up after a few hours.
This is the second X coil that I have used, the other being the 12 x 6 which is also excellent. The PL2 X coil combination is definitely a winner.

 

[Reg Wilson]

After having used three different X coils for some time now I have decided that the 12" x 6" spiral hybrid is my favourite. Some recent testing at the Coiltek test site at Lucknow lead has confirmed my earlier impressions. A number of coils from different brands were tested on an SD2200d, a GPX4000 and a QED PL3. Some coils were excellent on the smallest target, while others were better on the largest ones. Many coils struggled with some of the intermediate targets, whereas the 12 x 6 on all machines gave good signals on all, even the largest and deepest. (fives ozs of lead) The fact that the X coil could hear that target was a surprise as some of the smaller coils did not respond at all. I won't name the coils that were a disappointment, but will say that next to the 12 x 6 the Coiltek 18" was pretty impressive.
The biggest surprise of the day was that the SD2200d when fitted with large mono coils and run in fixed honked up the deep target best of all. Many settings were tried on all detectors, but they were ground balanced off the 'pad' and then passed over the signals so that false results from 'over tweaking' the settings were eliminated. The machines had to have settings that were usable in the general area.
As a QED agent I have decided to offer the 12 x 6 as an option on the latest PL3 as this coil takes the QED to a new level. This coil is actually two coils in one as the length gives a wide sweep for good coverage, while the unique spiral hybrid winding has great penetration and high sensitivity on even tiny targets. The only problem has been getting supply from Russia. The difficulties with freight make the X coil an expensive option, but worth the extra coinage in my opinion. Others must agree as they sell very quickly. At the time of writing I have only one left before I must order more.

 

[Outback]

After having used three different X coils for some time now I have decided that the 12" x 6" spiral hybrid is my favourite. Some recent testing at the Coiltek test site at Lucknow lead has confirmed my earlier impressions.
A number of coils from different brands were tested on an SD2200d, a GPX4000 and a QED PL3. Some coils were excellent on the smallest target, while others were better on the largest ones.
Many coils struggled with some of the intermediate targets, whereas the 12 x 6 on all machines gave good signals on all, even the largest and deepest. (fives ozs of lead) The fact that the X coil could hear that target was a surprise as some of the smaller coils did not respond at all.
I won't name the coils that were a disappointment, but will say that next to the 12 x 6 the Coiltek 18" was pretty impressive.

The biggest surprise of the day was that the SD2200d when fitted with large mono coils and run in fixed honked up the deep target best of all. Many settings were tried on all detectors, but they were ground balanced off the 'pad' and then passed over the signals so that false results from 'over tweaking' the settings were eliminated. The machines had to have settings that were usable in the general area.

As a QED agent I have decided to offer the 12 x 6 as an option on the latest PL3 as this coil takes the QED to a new level. This coil is actually two coils in one as the length gives a wide sweep for good coverage, while the unique spiral hybrid winding has great penetration and high sensitivity on even tiny targets. The only problem has been getting supply from Russia. The difficulties with freight make the X coil an expensive option, but worth the extra coinage in my opinion. Others must agree as they sell very quickly. At the time of writing I have only one left before I must order more.

Go Reg ! :Y:

Jack

 

[Aussiedigs]

X-Coils have to use DHL during this Covid-19 period and is costing Australia USD $80 extra.

 

[Reg Wilson]

Although the freight is exorbitant I am still charging the same 'pre Covid' price for X coils as I believe they add an extra to the QED performance, and If I sell a PL3, minimal profit on a coil is of little importance if it adds to customer satisfaction.

Mod edit:
Please note Reg Wilson is no longer a QED or X Coil dealer

 

[Aussiedigs]

Reg, are you able, if you have available, do some comparisons between say the 12x6, 12 and 15 X-coils? Sensitivity by depth?

 

[markrich73]

Hi everyone. First time post here, so here goes. :argh:

I've been soaking up everything QED on a bunch of forums for months now (Reg, your advice is golden!) and finally dived in a few weeks ago and bought one with a Sadie from Willtronics (423). I've been doing pretty well with it after being a long time Whites GMT user, where I'm used to the sharp zip zip on the tiniest targets. Getting a feel for the set up on the QED and and an ear for its signals has been quite a learning curve, but I finally snagged a nice little 0.43g nuggie last night in the GT (GB 300, THS B 46, THS A 18, GAIN 1, MODE 8). It was pretty close to the surface so the signal was strong and sharp. Mineralisation is quite high in that spot, so I find the ground stays reasonably quiet through my Sennheiser HD-25 headphones if I use a high mode with low THS B and THS A (it doesn't really show up in the photo, but there's loads of ironstone under the surface which is deep red to black-purple which makes my GMT go crazy).

I must admit, I'm struggling to pick up tiny targets with the Sadie even in air tests in MODE 1 and GAIN 10, whereas I detect shotties in the ground with the GMT and 5" coil to the point of annoyance. It's not an apples-for-apples comparison I know, but I've been going over spots twice - once with the QED then a second time with the GMT, which many times picks up shallow targets that the Sadie has missed. I know the QED is a super sensitive machine and I really want to get the most out of it. Reg I'm keen to try the X-Coil 12x6" to see if that improves sensitivity to the small stuff. Am I on the right track? I just want to be sure before outlaying the hefty expense.

 

[mbasko]

I think maybe running at the max ground balance setting of 300 isn't ideal. Have a read of this post by Reg:

A major development with the QED was the introduction of DSM (Dynamic Spectrum Modulation) which all PL3s now have as well as updated earlier models. This is an expanded ground balancing system with an adjustment range of 0 to 300. This advanced modification has made the QED a more user friendly PI detector with a more 'forgiving' ground balance. The factory default setting is halfway up the scale at 150, and in many cases the detector will be quiet with the coil raised and lowered at this reading in many ground situations.
To achieve maximum target response it is well understood that gain and mode must be adjusted for the best results, but ground balance plays a major role in top function as well. With bias set at a bare threshold either above or below null, depending on coil size and target size, it is time to fine tune ground balance.
Lets assume that you have tested ground balance in the default of 150 and found that the coil is quiet when being raised and lowered. Now adjust GB down until noise begins to come in when the coil is raised and lowered. Go back up towards null ( a couple of clicks) until quiet. You may now have a GB reading some distance from where you started, and will have a very sensitive setting. This works in situations both below and above null bias on small and large targets.
I have found some people who consider themselves as experienced detector operators make disparaging comments about QED when the real problem is that they are used to a different brand of detector and am unaware of how to get the best out of the QED.
Try this suggestion on a variety of targets and depths and you may be surprised at the difference a little adjustment can make.

The Sadie should be ok on the QED & able to pick up shot in air tests no worries. IMO it's your settings not the coil?
You gain seems way to low & mode too high for chasing smaller gold.
Try modes 1-3 & lift the gain up. Adjust the TH-B bias a bit back towards neutral if it seems to be too noisy. TH-A could probably go up to 40-50 with headphones also.

 

[markrich73]

Thanks for the tips Mbasko. I'm still a novice at this (and will likely be for months to come).

There are a couple of locations I've been prospecting where the machine just howls in some patches regardless of where the ground balance set, so I've just max'd it out at 300 and left it there. In the above location I couldn't keep it quiet under 280 even in the high modes. I'm not sure if I'm doing something wrong, but modes 1-5 were so noisy it was difficult to tell my 0.5 test nugget from ground noise - I certainly wouldn't have heard a target if I didn't know it was there. Mode 8 was the lowest I could get a steady(ish) threshold.

I just went out and retested a bb in the back yard. At THS B 47, THS A 40, Gain 10 and Mode 1 I could just detect a high-low when touching the coil, but the EMI spiking was really bad, so was difficult to tell target signal from EMI. Perhaps this is my problem in the field? I can't seem to shut the EMI up.

I'm heading back out to that spot again this afternoon, so I'll try what you're suggesting in location.

 

[Rush]

If I run some tests in the backyard then raising the Gain about 1 starts to create to much EMI for me.

 

[Rush]

Another thing does using a very low THS-B below Null be more prone to ground noise than using a very high Gain setting?

 

[XLOOX]

I have recently got a QED as well

At home when I first used her I also couldnt get above gain 1 due to noise. I found I needed to adjust SMR (setting 9) from default 107 to 137 to quieten her down enough to play around. Made a world of difference !!

If there is single phase mains interference, like in an urban area, until SMR is right it is a waste of time trying to adjust other settings.

I hold the detector horizontally & just keep turning slowly in a circle until I find what appears to be the worst EMI direction then stop turning & start upping SMR until noise starts to drop, then keep going until noise starts to rise again then leave it 1/2 way between.

If upping doesnt work then go down. I also found that the quiet "window" was quite narrow - like 135-139 in my case so if you hold the up or down button in then the SMR value might change too fast for you to notice the drop in noise. Better just move 1 number at a time.

Note though that SMR only fixes single phase interference - not 3 phase or other types. If it is too noisy at home then you might just have to wait until you are in the field - like all ML PI owners do .

I am lucky in that I have had no trouble with EMI out in the fied so far regardless of SMR at default or 137.

 

[mbasko]

I always found mine got pretty erratic the further away from the null point you got (low or high).
I preferred to stay at null or pretty close, within 1 or 2 of null, to keep it stable. Depending on coil my null could be between 48-52 & that's pretty much where I ran.
If I had a small coil (<8" ) on & null was 49 I might run at 48-47 or large coil (15">) on & null was 51 I might run at 52-53. Medium coils (9" to 14") usually just ran at whatever the null point is.

Then I used the lowest mode & highest gain I could without causing it to become unstable again. Found some pretty small sub gram gold doing that.
Raising gain can increase target signals but can also increase ground noise & EMI so it's a bit of a balancing act.
You want clear signals but not too much unwanted noise either so spending time getting the ground balance, bias (TH-B), mode & gain right to suit the coil/area is time well spent.

As indicated above - too much interference to do any proper testing in town. Get back out on the goldfields if you can.

 

[hippyhunter]

Hi everyone. First time post here, so here goes. :argh:

I've been soaking up everything QED on a bunch of forums for months now (Reg, your advice is golden!) and finally dived in a few weeks ago and bought one with a Sadie from Willtronics (423). I've been doing pretty well with it after being a long time Whites GMT user, where I'm used to the sharp zip zip on the tiniest targets. Getting a feel for the set up on the QED and and an ear for its signals has been quite a learning curve, but I finally snagged a nice little 0.43g nuggie last night in the GT (GB 300, THS B 46, THS A 18, GAIN 1, MODE 8). It was pretty close to the surface so the signal was strong and sharp. Mineralisation is quite high in that spot, so I find the ground stays reasonably quiet through my Sennheiser HD-25 headphones if I use a high mode with low THS B and THS A (it doesn't really show up in the photo, but there's loads of ironstone under the surface which is deep red to black-purple which makes my GMT go crazy).

I must admit, I'm struggling to pick up tiny targets with the Sadie even in air tests in MODE 1 and GAIN 10, whereas I detect shotties in the ground with the GMT and 5" coil to the point of annoyance. It's not an apples-for-apples comparison I know, but I've been going over spots twice - once with the QED then a second time with the GMT, which many times picks up shallow targets that the Sadie has missed. I know the QED is a super sensitive machine and I really want to get the most out of it. Reg I'm keen to try the X-Coil 12x6" to see if that improves sensitivity to the small stuff. Am I on the right track? I just want to be sure before outlaying the hefty expense.

https://www.prospectingaustralia.com/forum/img/member-images/17530/1599268069_0.43g_qed_nugget.jpg

Sort out your gb firstly which seems really wrong at 300. If your gb is wrong you will struggle with other settings more.
I have a bit of trouble myself working out which way to adjust from tones rising to raise gb etc. I find the agb method easiest for me to work out up or down in gb.
Just hold the agb button and bob up and down once releasing the agb button when lowered near the ground. You will see the gb numbers move just one or two numbers in one direction or another. That will indicate if you need to raise or lower your gb manually. After you get gb right the other settings should seem to work more as you originally learnt

 

[XLOOX]

I wrote on a bit of paper an stuck on top of screen box:

If coil DOWN gives high tone then decrease GB
If coil DOWN gives low tone then increase GB

If coil UP gives high tone then increase GB
If Coil UP gives low tone then decrease GB

I found that sometimes when GB was close to spot on that lifting the coil away from the ground gave a more positive sound to identify.

I also found that when I was confused as to whether the tone I was hearing was high or low ( I also have a Kruzer & TDI tones to remember ) the simple solution was to wind the GB up or down whilst bobbing SLOWLY until the tone changed then I could easily figure out which one was high & which one was low.

Then similar to my post above, it is easy to overrun the GB null point & miss the silent window if you keep the up/down button depressed so after doing an AGB to get a rough GB I go click up, bob, click up, bob, click up, bob until GBed perfect or have moved 20 points. If no luck after 20 points up then AGB again & go click down, bob, click down, bob ...

Havent failed yet to get a great GB with that method..... but it is early days

 

[markrich73]

Thanks for the great feedback everyone. (I feel like I've possibly hijacked the discussion? Please feel free to delete or move this post if it's too far off the topic on best coils for the QED.)

I went out again this afternoon to the same spot as yesterday (I think I've chosen the wrong place for troubleshooting my Sadie's sensitivity - it's littered with these noisy chaps below, which makes ground balancing tricky).

First I checked EMI and it was quiet. I then found the quietest bit of gound I could and AGB'd it up to 291. I didn't need to adjust up or down manually as there was an even pitch raising and lowereing the coil slowly to and from the ground (I bobbed it over a couple of spots to make sure). Set THS B to null, which was spot on 50, THS A to 40, mode to 3, gain to 6, placed a 0.15g lead shot on the ground and passed the Sadie over it almost touching it. Nothing. Lowered the THS B to 48, raised THS A to 60, mode to 1 and gain to 8. Again, not a peep. Tried again with the gain at 10, but to no avail ...although I know above 6 it plateaus in effect.

Does this sound right? I would have thought I'd get a little squeek or dicernible wobble in threshold at least. I put the 0.43g nugget I found yesterday back on the ground to make sure everything was still working and got a strong diggable signal to about 2 inches above it.

 

[hippyhunter]

Something is going on. You should easily be able to signal .15g.
Probably best to speak to reg for advice as sometging seems out.
Are you factory resetting each time out and doing settings from scratch or adjusting settings from last trip? Sometimes a factory reset helps me if i loose the settings.
But yeah. Should be getting a signal from your .15g so dont give up

 

[XLOOX]

If machine GBs ok at 291 from an AGB that would indicate super hot ground and I assume like most MDs, sensitivity is reduced in that case.

Question is - Is the ground really that hot or is something amiss with the detector.

What does your GMT think of this 291 GB ground and the 0.15g shot ? If it is not completely blown away on overload by the ground and struggling to see the shot then it is maybe time to drop back into Willtronics or call Howard.

As a comparison in milder ground, on my QED PL3 latest update, Sadie, GB 148, THSB 47 (2 under null), THSA 25, Gain 8, Mode 1, I can pick up my 1grain (0.065g) test piece at about 50mm under the dirt. Coil doesnt make a peep raising or lowering - just hear the threshold hum.

 

[mbasko]

I'm doubting the ground would be that bad so as to AGB at 291 but maybe?
IMO there's one of few things wrong. The ground is super hot reducing sensitivity; AGB isn't working (have you tried to manually balance as per Reg's method above?); the detector has an issue or the coil might (have you got or can you get another coil to try).
Definitely should be getting 0.15g with the Sadie.
It's not a SDC slayer in that ground ATM

 

[pinfire opals]

I wwould say your coils on its way out by the sounds of it, sadie should pick up lead shot all day mate, try another coil if you have one. :goldnugget: