1350 Question for Uncle Willy

[Dirt NC]

Hi Bill, The 1350 has four different operating frequencies. The manual says this is to cancel interference from another close -by detector by switching freqs. This is a great feature that I have found useful in club hunt enviroments. What i want to know is does any one freq. have an advantange over the others as in depth, mineralized ground, or at the beach. Thanks for any info you can give on this. I'm just trying to better learn this great machine.

 

[DavHut]

May I add in on this one, even if I aint Bill?

The freq separation you are referring to is only in fractional steps. From 7khz tp 7.3khz, for example. This won't affect the frequency response of targets much, if at all, as their detectable responses to electromagnetic fields change as a result of LARGE frequency jumps, say 7khz to 17khz. This includes the response of mineralized matrices, too, such as salt water beaches.

(However, it should be noted that free gold (pure) and the mineralized soils it is normally associated with responds better to higher freq's, which is why most dedicated gold nugget machines operate at significantly higher frequencies than coin detectors.)

But, regardless, all detectors are really miniaturized radio frequency phase shift detectors and each emits and recieves a signal of it's own internal creation in order to do it's work. While not exactly the same, they share similarities with the radar detectors the police use to bust you as you speed off to your next hunt site.

When seen that way, it's easy to understand why two detectors can "talk" to each other if they are operating on the same frequency - just like walkie-talkies!

So, if you shift the emitted frequency slightly (and without checking I'd imagine it is by an odd number), you "re-tune" your detector's receive circuits to a new and out of phase signal (an odd harmonic), when compared to the one it was working at (and which is the same as the other detector(S) at your club hunt).

This, then, eliminates the sympathetic reaction of your detector to another which may be working at the same frequency. In turn, this eliminates the dreaded "cross talk" one experiences when two detecors are on the same frequency, in proximity to one another.

I hope this helps.

 

[Uncle Willy]

They would if they were a big jump in frequency but that isn't the case. You're only changing the frequency between two numbers by degrees - like 7.2 to 7.3 on up to 8. Now if you could change it from 7.2 to 15 to 20 then you'd have a very versatile machine. This minute change does nothing for performance except eliminate cross-talk between detectors.

Bill

 

[Uncle Willy]

Yeah the detector is based on the old aircraft radio directional finder of many moons ago.

Bill

 

[Dirt NC]

thanks bill and dave. that is what i thought was going to be the case. thanks for clearing it up for me.