Ott Technologies Periscope Ground-piercing Metal Detector
By Joe Patrick
From Page 36
January, 2001 issue of Lost Treasure

For the past few years, I have noticed a steadily growing interest in handheld pinpointing metal detectors. Lately, there has been much curiosity, interest and discussion about the newest pinpointer to hit the detecting scene . . . the Periscope.

Unlike current pinpointers that are normally used during retrieval, the Periscope is used BEFORE retrieval, to accurately indicate the targets exact location, its metallic composition and its depth.

A thin, 14-inch ground-piercing metal rod houses a miniature long range directional sensor that provides an electronic signal to the Periscopes control-box electronics. Here, the signal is processed and through a series of unique audio tones, the range (distance from tip), bearing (direction from tip) and identification (metallic composition) of the target can all be accurately determined.

Periscope is the innovation of Ellen and Jim Ott who formed their company, OTT Technologies LLC, specifically to develop, manufacture and market Periscope, the ground piercing metal detector.

Periscope, with a patent now pending, is Ellens idea and is the co-inventor along with her husband Jim. Jims background includes more than 30 years in electronics as president of his own company, while Ellens career path was in aviation as a jet pilot for the Goodyear Tire & Rubber Co. They are now totally dedicated to Periscope and customer satisfaction.

Before I begin my evaluation, I want to express my complete admiration for Jim and Ellen Ott and the Periscope. This is a product that any person or company would be proud to put their name on.

Periscopes design, construction, functionality, attention-to-detail, documentation, tech-support and packaging are all exceptional. This is one of the most well-done products that I have ever had an opportunity to evaluate and field test. The fact that the Periscope is their first product and they seem to have gotten everything correct the first time around, makes it even more astonishing to me.

Features and Controls

Periscope is basically a handheld metal detector probe, but unlike any you or I have previously seen or used before.

It operates as a pulse induction metal detector using a miniature long range sensor placed inside a thin Zirconia-tipped stainless steel probe rod. The shaped magnetic field of this sensor can detect objects at distances that exceed 50 times the sensors diameter. It also reports an extremely accurate radial direction-to-target signal off the sensors side. The shaped detection field of the sensor enables the Periscope to use its hardened stainless steel metal shaft down to the sensor without the metal shaft interfering with the signal from the target.

The specially processed Zirconia tip will withstand a lifetime of being pushed into the soil and sand and is almost indestructible.

An ultra-sensitive pulse induction controller combined with a new Target Metal Type Analyzer measures BOTH permeability (inductance) and conductivity of the detected target, making metal-composition identification highly accurate.

Every aspect of the Periscopes construction is of commercial-grade quality, is heavy-duty and built for a lifetime of use.

Periscopes control panel consists of three knobs and four toggle switches. The knobs are a rubberized soft-touch type with a nice comfortable feel and the switches are rubber-boot protected from dirt and rain entry. Two, sturdy 1/4 inch phone jacks are used for the headphone and Surface Detector (your detector) connections. An Audio Select switch selects either the Surface Detector or the Periscopes signal to the headphones.

A unique plug-in four C-cell battery pack powers the Periscope. Only two batteries are required for operation and there is a Battery switch on the front panel that selects either Battery 1 or Battery 2. This option insures that you will never be without a backup battery pack while afield. If one set of batteries dies, simply set the Battery switch to the other set of cells and continue operation and detecting. A front panel LED is used as a battery indicator. It will light brightly when the batteries are exhausted.

A two-position Max/Norm Sensitivity switch provides a user-selectable option for the optimal sensitivity setting to match the ground mineralization of the users detecting site.

The three controls are: Volume; Pulse (Identification); Pitch (Range & Bearing). The Volume control adjusts the listening volume level and also includes the on/off power switch. The Pulse and Pitch controls are both 10-turn types that have an extremely smooth and positive mechanical resolution and feel to them.

The Pitch control varies the tone or pitch of the Range & Bearing tone.

A Verify switch with two positions A and B helps determine the targets metallic composition. Perhaps the following table will help explain it better.

Periscope has been optimized to provide the highest sensitivity to gold rings. The ability to differentiate between a pull-tab and a gold ring can be difficult but improves with experience. A larger gold ring will respond more like a pull-tab. This uncertainty between pull-tabs and gold rings is shared by all metal detectors. This is because gold rings and pull-tabs have similar electrical characteristics depending on their shapes, metal alloys and orientation in the ground.

Field Use and Findings

After closely examining the Periscope, talking with Jim Ott, reading the owners manual, visiting their web site and bench testing with various targets, I had a good feel for how the Periscope works and its capabilities. I was ready for the field.

Periscope comes with a Cordura hipmount pouch, belt, strap and several wearing options. I prefer hipmounting equipment with my standard military-issue web belt, as do many detectorists. Unfortunately, the Periscopes hipmount belt loops are not wide enough to use a military web belt. I was left with two options: Use the supplied, thin, Nylon belt or use the wider chest mount loops on the pouch. I chose to use the chest mount loops although this did throw the hipmount balance off somewhat. Periscope needs to lengthen the hipmount loops to about three inches width. Everything else was nicely done.

The extra weight is definitely noticeable, especially since I already use a hipmounted detector. Those who do not use hipmounted detectors will probably not mind the extra piece of equipment and extra weight.

Having about 20 years of detecting experience, I seldom experience any difficulty in pinpointing targets. Using a long-bladed hunting knife, I am usually able to pinpoint and retrieve a target in well under one minute.

Because of my well-developed, time-tested retrieval method, I found that using the Periscope did slow the recovery process for me, but it does make it highly accurate. Those with less detecting experience or undeveloped pinpointing skills may find the Periscopr to be an essential "retrieval tool".

There is something magical about knowing what a target is before retrieval. I found the Periscope to be extremely accurate at identifying iron, ferrous targets. I would say close to 100 percent accuracy! It was also very accurate at identifying coins and highly conductive targets, although I couldnt tell the difference between various coin denominations or even a screwcap and a coin. I did know however, that it wasnt iron or a mid-conductivity target.

Its a little difficult to explain the Range & Bearing and Pulse sounds without some hands on use, but I will say that they work well and do not take very long to learn. Basically, as the arrow on the probe handle is rotated toward the target and as the tip nears the target, the Range & Bearing audio tone increases in frequency. Once you have determined where the target is, you can now use the Verify A and B switch positions to find out what type of metal the target is made of. Its actually very easy to do.

I did find the probe handles pinpoint arrow to be somewhat difficult to see in some lighting. Its highly-reflective design needs to be rethought. Perhaps a higher contrast, less reflective arrow would be better. Maybe a broad, hot-stamped arrow filled with a highly visible fluorescent orange color.

The Audio Select switch lets you instantly switch back and forth between your detector signal and the Periscopes signal. A small, coiled cord similar to a short electric guitar cable connects the Periscope to your detectors headphone jack.

All-in-all, I found the Periscope to perform very well and was extremely pleased with its performance and accuracy. It is a fantastic detecting tool that quickly builds user confidence, increases overall desirable-target productivity and increases pinpointing accuracy immensely!

I did not have much difficulty inserting the probe at the sites I detected, however, weve had a lot of rain this year in Pennsylvania and the ground has been ideal. Those who detect in areas where the ground is too hard or rocky to dig with a shovel may find the Periscope unusable. Those who detect the beach will probably find it to be indispensable.

A good way to judge if you can insert a Periscope into hard ground at a site is to insert a #2 Philips head screwdriver. The Periscope will require about the same force and be more confortable to use becasue it's Nylon handle is ergonomically designed to properly fit the hand when applying downward pressure.


Few detecting products have impressed me as much as the technically-advanced Periscope. It is a very innovative, cutting-edge product that works extremely well. Ott Technologies LLC is a first-rate company with a first-class product backed by real dedicated people . . . Ellen and Jim Ott. If you are looking for the ultimate pinpointer, the Periscope is it.

The Periscope currently sells for $549.95 and includes a $58 accessory package for free. There is a Complete Satisfaction 30-day full refund guarantee and a 1-year warranty. For additional information contact: OTT Technologies, LLC, 3867 West Market Street #276, Akron, OH 44333. Phone: 1-330-668-4703. FAX: 1-330-668-3817. Toll Free: 1-888-568-4021.

Be sure to visit their excellent web site at: http://www.down and once there, also check out their Gallery page at: You can also download the Periscope owners manual (PDF format). There is a lot of information available, so take your time and look around.
Copyright © 1996-2018 LostTreasure®, Inc. All Rights Reserved.