Coil Frequency

[broadfield]

I was listening the other day to C-Scope talking about the new Evo-6000. They said they opted for single frequency operation with the coil set for one frequency as it is better as it resonates at it's design frequency, in this case 17khz. They did say there will be option coils to change the frequency higher or lower but this will mean purchasing a new coil to change frequency.

Is this truly the best way to achieve the best sensitivity at a given frequency or are they just holding on to old tech.

There are other makes of detector that you can change frequency with the same coil (Deus, ORX, Kruzer, Anfibio, Nox etc) do these machines have a set resonate frequency matched to the coil which offers best performance and do they lose sensitivity if you change frequency? Or is there a way of making the coil sensitive to a range of frequencies.

Just wondering why they chose to go a different route to others on the frequency selection?

[Mike Hillis]

They probably have trouble with their multi-freq coil nulls and instead of putting any more effort into them decided to follow the old Minelab Xterra money pit model.   But if you need 100 levels of iron volume adjustment this is the detector for you.

HH

Mike

 

 

[Johnny Crunch]

If it's anything like antenna design, it's probably a trade-off between broadband (multi-freq) and sharply optimized (single freq). Perhaps an analogy is photographic Zoom lens vs Prime lens. Zoom is flexible; Prime lens can only do one focal length, but is unsurpassed for sharpness. Maybe an EE or coil designer can correct my [mis]conceptions...

[EL NINO77]

It is also worth mentioning the Rutus Alter 71 detector, which has a continuously variable frequency from 4.4 khz - to 18.4 khz .. where the detector calibrates the coil after changing the frequency ...

Another detector that calibrates the coil when changing the frequency and even very sharply is the detector Aka Signum Mfd ..

  Here it is still necessary to consider the technical concept of the detector itself ..., I say the same technical detection philosophy - the direction of the detector manufacturer ... and it really varies with different detector manufacturers ...

if the frequency or the frequency of 17,5 khz can be sufficiently universal, then I can answer that it is OK ..- when the detector is technically ready to use this working frequency really well.

[GB_Amateur]

On 11/9/2020 at 8:28 AM, Dan Fox said:

the new Evo-6000

Could you (or someone) link us to more info on this coil.  From the 'Evo' in the name I'm assuming NuggetFinder coil for PI detectors.  But I really don't like to assume....

 

[GB_Amateur]

35 minutes ago, phrunt said:

See the operating temperature taps out at 30 degrees c... cant even use it in Australia 🙂

I wonder if that's a typo given that the max temp in F units is 120 (almost 50 C equiv.)  Either that or you can run under higher ambient temps only in countries that refuse to convert to the metric system. 

I wonder if "Speeds    10" refers to recovery speed.

[Tom Slick]

And that's just one more reason we in the U.S. never switched over to using the Metric System. You'll notice that many detectors manufactured outside the U.S. are not sold in the U.S. They don't work here! 🤪