Question for Easy Money about Compass and Red Heat

[Deese]

What type of circuit are the detectors that have the iron see through? I guess not vlf since the compass 77b is a 100khz machine.Are they induction balance? or something else?

 

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[kando]

What type of circuit are the detectors that have the iron see through? I guess not vlf since the compass 77b is a 100khz machine.Are they induction balance? or something else?

My self ithink they are VLF....---------- Deese i went to click on profile and clicked ignored by mistake did not know how to take it out.

 

[dazoff]

They are induction balance which is the same as TR .Dan

 

[EasyMoney]

Deese

Actually those detectors are a form of induction balance (IB) as are the newer (and new) ones made today, however unlike the true original IB machines such as the old 70's White's, A.H. Pros, Fishers, etc. The original TR's are not true induction balance detectors, they are Transmit/Receive in configuration and are not able to balance the signals at all, but instead tune to the ground purely on edge all the time, and the worse the ground is, the worse it is to keep them tuned to the ground . An "induction balance" detector is really a form of an original yet simplified "ground balance" variety.

What normally eludes most people is the fact that a discriminator is little more than a "fine-tune" "ground balance". In other words, if a detector has a ground balance in it at all, manual or "automatic" it is much like having a rough adjustment to balance the signal of the soil (ground, iron, etc) to the air above it. This is merely saying that it finds a happy medium to operate in between the two, hence, "balanced" between the air and the ground (usually it's iron content, but not always it's iron content though).

Any old so-called (but really true) A.H. Pro or White's or Compass, etc. with metal/mineral adjustment is a true induction balance (IB) detector. This GB or G(Exclusion)B (GEB) adjustment is also used to control (to some degree) the squawking made by the detector as it comes up and/or away from the soil it was adjusted originally "balanced" to. Those old beasts didn't have an automatic quick capacitive circuit to save them and put them back running smoothly though.

So, as you can see, an IB circuit does have somewhat of a fair capacity to "see through" iron, or "cancel iron' or other equally conductive materials, including salts, etc. This means that yes, the IB is a bit of a discriminator too, since it has the inherent property of canceling iron to some degree.

But usually these old circuits are some real dinosaurs, at best, and can't compete in the bad soils as well as some crystal-controlled, fast retuning, fast return to threshold modern detector made after the 80's. In short, they don't have as good of see-through capabilities as the newer ones do.

So since about 1979 or 1980 all detectors save for PI's and magnetic spectrometers, BFO's, BBF's, etc are a form of IB's and DO HAVE "iron see through" capabilities, but some do better than others and for multiple reasons too, depending on the brand and it's inherent circuitry design, and not necessarily it's freq of operation.

Nowadays though, and even with the Red Heats or Compasses the higher frequencies are usually easier to adapt "iron see through" controls to. But this is also a very loaded statement too, because some detectors have such sophisticated circuitry in a low frequency operand (even down to 3.5 Khz) that they can actually discriminate or "see through" iron as well or better than a high freq machine (100 Khz), and it all depends on a lot of some very well-engineered effort and design by the manufacurer.

Hope this helps.

EEZY$$.