building a coil for Quest Series Detectors Q20 Q40 X5 X10

[bernte_one]

Here ist what i measure for my small elliptical DD coil from my Quest Q20 detector.

Next weeks i will try to build a 35cm round DD coil. The commercial offers for replacement coils for Quest Series is not less.
Most of the third party manufactures have build some models for the Quest detectors, so i should not be a witchcraft.




But i think i can need some info and tips from you all.
For me its not so clear at moment where to shield the coil

[bernte_one]

i made some calculations
for one side of 35cm DD coil i need a length of 0,9m per turn

so it is no secret which wire diameter are used in original coil
from pin 1+2 it are 10T 0,3mm wire, calculated 0,108mH and a calculated resistance of 2,1R

pin 2+3 the same (ech part length of 9m)

pin4+5 RX side it takes 84T of 0,2mm wire, which gives 6,805mH and a calculated resistance of 40,9R (length of 75,6m)


coil could be improved by using 0,4mm wire 10T for TX side which give the half Resistance or 11Turn with 0,5mm wire (less than 1R)

[SVEN1]

My Quest Pro coil.
A number of years back I received a stock size coil from the China factory. They wound the coil wire bundles and they supplied the shell.

I did an experimental shield by wrapping the coil bundle in carbon fiber tape. It worked great no falsing and worked just as good or better than the factory coil.

[Skippy]

When I saw your coil measurements, I immediately though "T2 !", not only do they look close, but the centre-tapped TX is uncommon, the Teknetics T2 being a popular machine that uses this arrangement... then there's the well-known fact that some of Quests product were 'inspired' by the T2, to be polite.

The T2 coil has RX = 6.95 mH & 37 Ohms; and TX = 690 microhenry (total) and 2.1 Ohms (total ) , with a centre-tap.

I've just looked at my T2 data, and the pinout of the connector is exactly as per your diagram for the Quest, as well.

I've never made a centre-tapped TX coil, but I think it should be wound bi-filar ( two wires together ) , this will give a very symmetrical coil.
Do not "wind 20 turns, bring out the tap, wind another 20 turns"
Also, when measuring a centre-tapped coil, just measure the total inductance. The measurements for each 'half' will be meaningless, they will not be one-quarter of the total, because of the 'unused' wire reducing inter-winding coupling.

You should look out for a secondhand large T2 coil on eBay, if it proves to not be compatible for some reason, it can be re-sold with little loss of money.

[ivconic]

When I saw your coil measurements, I immediately though "T2 !", not only do they look close, but the centre-tapped TX is uncommon, the Teknetics T2 being a popular machine that uses this arrangement... then there's the well-known fact that some of Quests product were 'inspired' by the T2, to be polite.

The T2 coil has RX = 6.95 mH & 37 Ohms; and TX = 690 microhenry (total) and 2.1 Ohms (total ) , with a centre-tap.

I've just looked at my T2 data, and the pinout of the connector is exactly as per your diagram for the Quest, as well.

I've never made a centre-tapped TX coil, but I think it should be wound bi-filar ( two wires together ) , this will give a very symmetrical coil.
Do not "wind 20 turns, bring out the tap, wind another 20 turns"
Also, when measuring a centre-tapped coil, just measure the total inductance. The measurements for each 'half' will be meaningless, they will not be one-quarter of the total, because of the 'unused' wire reducing inter-winding coupling.

You should look out for a secondhand large T2 coil on eBay, if it proves to not be compatible for some reason, it can be re-sold with little loss of money.

Yesterday in the evening i got brand new Quest X5. I had previously 33x26cm coil for Teknetics T2, made in Ukraine. Was uselles, staying for some time in a drawer.
When i measured Quest stock coil inductances... something looks familliar to me?? The bell rang and i recall the T2 coil that i had!
So i checked its inductances; matching almost 100% with Quest coil!!!???
WTF?!
So i only needed to rearrange wires in connector at T2 coil to match Quest connector.
Hooked up, switched ON... WORKS! Like a charm!
It can GB ferrite rod completelly!
Air depths improved significantly, roughly 50-70% !!!!
Astonished!
I could not belive what i see!
WTF!
I still don't know the Quest country of origin? From where the f... it came? Who makes them?

I am trying to upload some photos... no success?!

[Skippy]

Quest used to be called 'Deteknix' , at the time it was discovered they had used Teknetics code in the micro of one of their products. Carl knows the details.
As a result of the legal proceedings, which they lost, they changed their name, which was probably 'stolen' too, from a UK detector retailer. Clearly if the detector is/was running hacked T2 micro code, the rest of the machine must be pretty similar, including the coil.

They are officially based in USA, but that is mostly an office, the manufacturing is somewhere oriental.

[ivconic]

Strange... previously in Chrome i couldn't upload photos.
Now in Epic browser (VPN active) i can upload photos.
This is question for admins...

[ivconic]

Quest used to be called 'Deteknix' , at the time it was discovered they had used Teknetics code in the micro of one of their products. Carl knows the details.
As a result of the legal proceedings, which they lost, they changed their name, which was probably 'stolen' too, from a UK detector retailer. Clearly if the detector is/was running hacked T2 micro code, the rest of the machine must be pretty similar, including the coil.

They are officially based in USA, but that is mostly an office, the manufacturing is somewhere oriental.

I didn't know that, thanks for clarification!
That explains why T2 coil works splendid with Quest X5.

[ivconic]

[ivconic]

Sites are totally exhausted... damn!
Only two rotten Roman coins today.
Quest X5 is quite alright machine, i like it.
I have no remarks so far.
Also for the first time took F-Pulse outdoor.
Impressive! Hell of a pinpointer!
...
It is somewhat annoying to record such videos with the telephone, must obtain go-pro camera any sooner.

[kroman01]

Quest Q30 coil, please help, the plug fell off, how to connect it