QED Info Thread.

[Rush]

Interesting that even in a high mode and lower gain small targets still give a clear signal if bias is set accordingly.

Yes I agree from my experience using the QED.

 

[Reg Wilson]

golddigger dave, both Dave79 and Rush seem to be in tune with their QEDs. Firstly, let me just say that I am no electronics wizz, and Howard would be able to give you a more precise description of the functions of Mode and Gain, but I shall attempt to describe their effects as best I can.
I would compere Mode to a form of sensitivity. 1 is the most sensitive setting, and in very mild ground conditions will give the best target response, however as ground conditions get hotter the Mode must be increased to suit. Mode is also important in matching coil to electronics, to give the best combination. When setting Mode, Gain needs to be adjusted as high as ground noise will allow. A balance between Mode and Gain is important in attaining a smooth yet responsive compromise. Also the lower the Mode setting the longer the battery life. If very nasty ground requires a high Mode setting, do not despair, as only a little sensitivity is sacrificed.
Hope this makes sense.

 

[golddigger dave]

Many thanks to Dave79, Rush and Reg
Gain and mode are puzzlers for me.
eg. If you put a different coil on. Do the GB and NUL.
How do you find the mode and gain numbers for it on the ground that exists?

Thanks All,
Newbie Dave (Geelong)

Gold is where it is, but i was somewhere else

 

[Reg Wilson]

golddigger dave, when changing coils it is a good idea to reset Bias, Mode, Gain, and finally GB. When you turn on your machine it will return to the last settings used. With practice you will have a good idea of the readout that suits each coil, and only need to GB at different areas.

 

[golddigger dave]

Thanks Reg.
In this case, GB LAST !!
Would have taken me 10 years to work that one out.
This is experience talking. Stuff you do automatically. Not in the videos etc.
Very much appreciated.

Thanks Again,
Newbie Dave (Geelong)

Gold is where it is, Maybe where i am too.

 

[Tathradj]

I don't like saying this as I am looking hard at a QED but,
my moderators 6th sense is starting to stir a bit.
Have a close look at your wording people. {)
Reg, Can you PM me please. :Y:

 

[mbasko]

I really have no idea of the function of MODE and its effect on the machine.
Then comes Gain. What does Gain adjustment do to the mode setting?

Mode is simply the QED's pulse delay adjustment.
Pulse delay is basically the delay from when the current is sent to the coil to when it shuts off in milliseconds (us).
Low conductors, like smaller gold, have a short signal decay time (short delay) from the end of the transmit pulse and high conductors, i.e. silver, larger gold, have a longer signal decay time (longer delay). This means that using a lower pulse delay (mode) is better for low conductors.
I was told awhile back the modes on the QED start at 8us & go up about 0.4us each mode increment? I.e. mode 1 is 8us; mode 2 8.4us & so forth thru to mode 15. Not sure about mode 16 (Beach mode) but would think it could likely be around 20us. Don't know if these are the correct starting us & increments as haven't seen anything official on the values from Howard but they will help explain what you are asking here regardless. Basically the lower modes are better for smaller coils chasing smaller gold.
If the above figures are correct (or close) it means that the QED pulse delay is set relatively low right through the modes which explains why it remains sensitive even in higher modes.
One thing I found with the QED is don't get hung up on thinking you need to use the lowest mode to find smaller gold. Use a mode where you're happy with how the detector is running with the coil being used.
Gain basically just amplifies the signal but it also amplifies unwanted noise like ground noise & EMI. Once you have settled on the mode I would start at a low gain & adjust up until the QED becomes erratic/noisy then back off one or two. Keep it as high as you can for the area.

Bias also comes into play with mode to.

Smaller coils <<< lower modes <<< lower bias ---- neutral bias ---- higher bias >>> higher modes >>> Larger coils

While the above is fairly general to how to best set up the QED it is versatile in settings. I.e. in some situations a smaller coil may operate better in a higher mode but still be set towards a low bias & still maintain good sensitivity. A lot comes down to what the operator is happy with for specific coils & areas.
Hope that helps/makes sense.
Pl2 manual here:
https://www.prospectingaustralia.com/forum/doc/member-docs/4485/1537594201_qed-pl2-manual-b-oct-17.pdf

 

[Crow Pickens]

Hi All.
My Attempt at Handle Cover. The ribbon wire fits nicely under the cover.

Cheers Crow Pickens

 

[Jaros]

Doesn't have to be pretty. As long as it works.

 

[Reg Wilson]

Crow Pickens, looks like you've got yourself a good little QED accessories business. I suggest you get in touch with Pete at Detech, as it would be good to see your products at the Laanecoorie Bash. I'm sure there is a market for your covers. Good luck with your venture.

 

[Rush]

This is a diagram I modified from an existing diagram which maybe of some assistance to users.

 

[egixe4]

I really have no idea of the function of MODE and its effect on the machine.
Then comes Gain. What does Gain adjustment do to the mode setting?

Mode is simply the QED's pulse delay adjustment.
Pulse delay is basically the delay from when the current is sent to the coil to when it shuts off in milliseconds (us).
Low conductors, like smaller gold, have a short signal decay time (short delay) from the end of the transmit pulse and high conductors, i.e. silver, larger gold, have a longer signal decay time (longer delay). This means that using a lower pulse delay (mode) is better for low conductors.
I was told awhile back the modes on the QED start at 8us & go up about 0.4us each mode increment? I.e. mode 1 is 8us; mode 2 8.4us & so forth thru to mode 15. Not sure about mode 16 (Beach mode) but would think it could likely be around 20us. Don't know if these are the correct starting us & increments as haven't seen anything official on the values from Howard but they will help explain what you are asking here regardless. Basically the lower modes are better for smaller coils chasing smaller gold.
If the above figures are correct (or close) it means that the QED pulse delay is set relatively low right through the modes which explains why it remains sensitive even in higher modes.

Hi mbasko,

Your description of mode is pretty much spot on :Y:

Mode 1 is around 7s - Mode 15 is around 15 s (From Howard)

Also of note, some coils perform better at a lower Mode than others over the same ground
For instance my
8 Commander runs nice at mode 1
Where a similar size NF need's mode 5

 

[egixe4]

Anyone tried a large coil say like a 18 inch on the QED , I believe from what I have read the QED only seems to operate well on certain coils , would be good to find out what works well and what doesn't

I use an 18" NF Advantage open spoke, runs awesome on the QED erfect:
and yes it's found it's fair share of Gold.

 

[Tathradj]

Looks like the NF coils are the best match.
I have a collection of them and about to add
one more.

 

[egixe4]

For a mid size coil the 14" Coiltek Elite is also outstanding on the QED.
Both Reg and Jr have done well with Elite's
I've not been happy with my NF 17x13 on the QED

 

[Rush]

The thing that annoys me the most about the Evo coil is trying to pinpoint and visualize the position of a small target under the coil due to the flat wound windings. I expect the same problem exists with the Elite and Detech as well.

 

[golddigger dave]

Pinpointing with large Coils
This is where you have a dual head machine and you flck over to your pinpointer coil.

 

[egixe4]

The thing that annoys me the most about the Evo coil is trying to pinpoint and visualize the position of a small target under the coil due to the flat wound windings. I expect the same problem exists with the Elite and Detech as well.

Hi Rush,

I also have problems pinpointing with the EVO, but strangely, don't have the same issue with the 14" Elite.
Not used the Detech Mono's yet so can't comment on those.

Mal

 

[Ded Driver]

The thing that annoys me the most about the Evo coil is trying to pinpoint and visualize the position of a small target under the coil due to the flat wound windings. I expect the same problem exists with the Elite and Detech as well.

Hi Rush,

I also have problems pinpointing with the EVO, but strangely, don't have the same issue with the 14" Elite.
Not used the Detech Mono's yet so can't comment on those.
Mal

my plan for my next outing is to have my son following up behind with the baby 5" DD coil on the Monster for pinpointing
that should keep him focused :lol:

 

[Rush]

My mate with a 5000 told me he tired using his Pro-Find 25 pinpointer to pin point while using his Evo however he would have to switch the 5000 off as the Pro-Find 25 caused interference once he switch it on.

I wonder if the Pro-Find 35 produces the same problem?