• Inductive HF Mode – induced through the soil, asphalt, etc.
• Inductive Clamp HF – induced through a clamp around target.
• Direct Connect or Conductive Mode – HF & LF through clip on.
• Switchable “On the Fly” – HF or LF or Magnetic – at Receiver.
• Passive Live Cable Mode – energized 50/60-cycle primary Power.
• Magnetic Mode – Ferrous Metal Locator.
• RF Locating at 82.5 kHz which is HF.
• AF Locating at 571 Hz which is LF.
• Medium Range Frequencies not used because of disadvantages listed.
• Powerful Transmitter (1-watt). HF locating up to2,000 feet, LF up to 4,000.
• Depth Detection via Triangulation.
• Null Over in RF/AF Modes, Peak over in Magnetic Mode.
• Strong, Durable, Designed for Ruggedness.
• Speaker or Headphone Use.
• Light-weight Receiver only1.2 kg, 9-Volt Lithium or Alkaline batteries (2).
• Transmitter designed into rugged pressure molded carrying case.
• Receiver fits into transmitter case.
• Magnetic Mode – passive – no signal emitted.
• HF – High Frequency Mode is transmitted at 82.5 kHz.
• LF – Low Frequency Mode is transmitted at 571 kHz.
• No unnecessary “bells & whistles” to confuse the operator or malfunction.

Now with the MAC-51Bx, you truly have the best of three worlds,High Frequency Locating, Low Frequency Locating (transmitted simultaneously) and Magnetic Locating, switchable on-the-fly, you don’t have to return to the Transmitter to switch into another locating mode if you have it directly connected. You can pick the mode which is the most advantageous for you application, and be able to switch to another whenever you wish.

• Can be used as a Magnetic Locator to find ferrous targets such as manhole covers, valve boxes,
  iron & steel pipes, marker magnets on plastic. pvc pipe, surveyor’s corner markers and PK nails,
  unexploded ordnance (best left to the professionals) and police searching for discarded
  weapons.
• Use to find the joints in iron & steel pipe – even if they are welded together.
• Use to find septic tanks (the handles), buried waste drums and canisters.
• Can be used while RF/AF locating to determine if a target is iron or steel.
• Can detect live 50/60 cycle power lines with a distinctive “warbling” sound.
• Can distinguished between live 50/60-cycle power line and steel or iron pipe.
• Does not detect tin cans, pop tops, coins, chewing gum wrappers, etc.
• Is totally passive – sends out/receives no RF or AF signals.
• Does not require a Transmitter … the Receiver is the magnetic locator.
• Much greater depth range than ‘ metal detectors” because of using earth’s magnetic field instead
  of pulse-inducted signal which dies quickly.
• There are no disadvantages to having an optional mode no one else has!

It is possible to pick up the magnetic flux from a larger-mass target in the vicinity of smaller ferrous metals, by reducing the sensitivity so that the smaller targets are missed, and only the larger on detected. Also, physically raising or moving the locator away from the target reduces the sensitivity faster because the percentage of change in distance is greater than the sensitivity settings on the locator. For example, a very large steel drum may be found under concrete disappears (or by raising the locator until the rebar disappears), then searching for the drum whose signals will be much stronger than the rebar that you have tuned out.Remember that magnetic flux flows from and into ferrous metal at the ends, therefore, steel rebar has it’s strongest signal at the end of every piece. Also, if the installer used steel wire to tie the bars together in a grid pattern, even the steel ties may be detected causing confusion as to where the exact end of a bar is located.Remember also that the magnetic flux flow the same in a stalk of pipe, even if the pipe stalks were welded together instead of clamped at the joints. Therefore, a run of pipe (a pipeline), will have magnetic signal peaks at every joint. To magnetically trace a pipeline, you would search for each joint as you walk along and mark then on the ground. Looking then at your markers, you will see the run of the pipeline.

Properly performed, magnetic locating can be so accurate as to detect a “PK” 1-1/2″ nail used in survey marking up to 18″ under asphalt, and pinpoint the spot so that you could hit the nail with a ½” drill.