High Frequency coils

[El Dorado]

Sorry if this has already been spoken about but, what is the difference in the coils other than the size?

[Hauptmann aD]

This high frequency - its much higher for the elliptical (around 80 Khz).

[Dave8472]

Also the new white ones do not go down in frequency as low as the black ones.

22.5cm (9”) Round DD coil:
13 to 15.7kHz, 26 to 31kHz, 50 to 59kHz
24 x 13cm Elliptical DD coil:
13 to 15.7kHz, 26 to 31kHz, 68 to 81kHz

Black coils

4 frequencies (4kHz ; 8kHz ; 12kHz ; 18kHz) + shift plus/minus

Despite all the excessive hype, the advantages in the UK are minimal for the white coils, unless you are searching for small gold nuggets or in heavily mineralised soil then the black coils have more advantage with the lower frequencies for depth, and 12-18khz is more than adequate for small hammered without loosing all the depth.

Dave

[Kaleb]

Despite all the excessive hype, the advantages in the UK are minimal for the white coils, unless you are searching for small gold nuggets or in heavily mineralised soil then the black coils have more advantage with the lower frequencies for depth, and 12-18khz is more than adequate for small hammered without loosing all the depth.



This is a good video showing the elliptical coil in use on UK soil and also on a highly mineralised test bed, I know air tests are not the same as being in the field but it does look like it has a use on some sites. I have one coming Monday and looking forward to seeing how it performs.

[Rivers rat]

Testing the elliptical at the moment on the Thames and having fun....


RR

[Kaleb]

Had an hour out on pea stubble earlier with the HF Elliptical coil on a highly iron contaminated area and had 2 hammered and a small buckle in amongst the iron, early days but very impressed.

Stock HOT with sens lowered to 86.

[Jungle]

Using it in rape stubble on HF 28Khz, going over a patch I've done before. Usual finds except cut quarters coming up but also digging bits of horseshoe which I don't normally.

[Kaleb]

Same here been caught out a few times on broken bits of horseshoe without the XY screen, With the XY screen it shows up as a horizontal line.
Never found so many 22 pellets and tiny pieces of lead going over previously detected areas, loves hammered coins and Roman grots on 74khz but yet to try the other 2 frequencies.

[Mud Max]

The amount of positive comments from those who are using the HFs speaks very well for them.

[Jungle]

Same here been caught out a few times on broken bits of horseshoe without the XY screen, With the XY screen it shows up as a horizontal line.
Never found so many 22 pellets and tiny pieces of lead going over previously detected areas, loves hammered coins and Roman grots on 74khz but yet to try the other 2 frequencies.

I'll give the XY a go and see if that helps with the iron. Not had so many cut quarters since the F75.

[cyprio42]

Hi
what frequency are you finding best for the hammys when using the 9" HF coil
thanks

[Jungle]

Hi
what frequency are you finding best for the hammys when using the 9" HF coil
thanks

I was using 30Khz. Just cleaned up last week's finds and there was also a fragment of a cut quarter, smallest bit of silver I've found.

[Hauptmann aD]

Some pieces of coins found after an archaeological dig with elliptical coil, mainly on 30 KHz: