Pros and Cons of SF and MF Detectors

[Cody]

There are a number of advantages and drawbacks to both single frequency detectors compared to multiple frequency machines. Let me give a little background on single frequency and explain how we ended up with VLF and multiple frequency.

The first ones to be patented was single frequency (SF) and the coil was driven by a sine wave. I seem to recall the operating frequency of my first TR to be about 50khz. Not long after that the frequency was changed to about 6.5khz as far as I can remember. These machine had one major problem in that a detector will detect anything that is conductive. Iron minerals are detected, wet salts, refined iron, alloys and precious metals so there is the good and bad.

The first ground balance detector was invented by George Payne and was a single very low frequency detector. The VLF was designed so that it would ignore pure iron ferrite. Since we don

 

[Ralph Bryant]

Good information Cody.

Other than the more obvious (saltwater beaches), what are some common areas of both salt and iron mineralization being present at the same time ? I know a friend and I hunted a recreational salt flat area in Utah many years ago that really did not give us much of a problem.....at least until the day it rained. WOW ! Alkali out in some gold-bearing areas of the S.W. acted very similarly when it became wet in the rainy seasons.

Somewhere in Eastern Oklahoma between here and your place is a short valley referred to as "salt hollow". A hunting buddy has mentioned it several times as very geologically "strange", and it supposedly has some thermal springs and what he described as "metal pellets" around some oil pools or slicks. The rock formations around the valley also have internal pockets containing "Herkimer Diamonds", or double termination quartz crystals. This area is also supposed to be one of the oldest exposed geological formations west of the Rocky Mountains. There are also some old building sites there that might be worth investigation.

Ralph

 

[Cody]

Salt is a problem if wet but I don't think it is if just damp and part of the soil matrix. There is a place where I hunt and it is fine unless it is really wet and after a serious rain then I might as well forget it. I believe this is salt causing the problem. I suspect most soil such as parks, yards, have some kind of conductive salts, fertilizers, mix with iron minerals which is the "soil matrix". I am not sure we have in most situation just one or the other which is why it is mostly a problem when at a saltwater beach.

Bill on the X-Terra did a great post and appears to have a very good understanding of the salt and iron mineral problems and multiple frequency compared to single frequency. I am thinking that the X-Terra is going to be a good trashy park machine and light plus easy to use. I was out today with my Explorer on private property and sure wished I was in a park with the X-Terra. My arm was getting tired and the fields were wearing my legs out.