The Ortovox S1 was released in 2007 and discontinued in 2011.

Overview: The Ortovox S1 is unlike other avalanche transceivers on two fronts. First, it has a flip-phone design where you flip the transceiver open to initiate search mode. Second, the S1 displays multiple burials on a computer-like display which is analogous to seeing the victims on a map. You line-up one of the victims on the screen and walk toward him, rather than following a traditional direction indicator that points to the victim. As you move toward the first victim, you can see other victims pass you on the sides. The grid concept is good, but because transceivers follow flux lines, which means the transceiver can be off by 180-degrees, trying to display victims on a grid is more optimistic than the 457 kHz frequency provides.

The Ortovox S1+ was released in late-2011 and the S1 model was discontinued soon after. This review is for the S1 avalanche transceiver. These core features of the S1 and the S1+ are very similar.

Searching: To switch into search mode, you press a button and flip open the Star-Trek-like lid. During the signal search (when you are seeking an initial signal), a little man is shown walking a zigzag path on the screen. This is a good reminder of what you should be doing, although someone completely unfamiliar with the S1 might take the image literally and think they should turn right, or left, when the little man does. The S1 and S1+ have a recommended search strip width of 50 meters.

A supine man is displayed on the screen when you receive a signal. You then perform the coarse search by turning the transceiver until the vertical line that is displayed on the screen is on top of the man. The S1 (and the Barryvox S and Pulse) uses an internal compass and/or motion sensor to help sense when you turn.

If you do not hold the transceiver level while searching, a "tilt" symbol is displayed indicating that you should hold the unit level. Likewise, a triangular "warning" icon is displayed if you should stop moving while the S1 processes information.

When you are within approximately 3 meters of the victim, a "patented circular illustration" is displayed (see below) to complete the fine search. The illustration uses a combination of highlighted circles and four arrows to indicate if you are moving closer to, or away from, the victim. I found this reasonably intuitive, although I tend to focus on the distance number which is very responsive. (An update on 10/2011 enables you to activate this mode sooner for deeper burials.)

"Circular Illustration" During Fine Search

The audio feedback on the S1 increases the cadence of the beep as you near the victim (as do the Barryvox 3000, Ortovox X1, Ortovox Patroller, Ortovox D3, Ortovox 3+, and the Pieps). The ARVAs, Mammuts and Trackers increase the cadence and pitch which is a little more intuitive.

"After the S1 receives the initial signal, the instruction to pivot the S1 can appear."

I have occasionally seen an oddity during the coarse search where if I am near the limits of the S1's range when I first receive a signal, and I am pointed 90-degrees to the victim (i.e., not getting closer to the victim as I walk), the S1 will continue to point me straight ahead until I eventually lose the signal. When this occurs, the transceiver prompts me to swing the transceiver from side-to-side (see the illustration, above) in an effort to relocate the signal. I'd prefer it if the S1 would shorten its range and make sure that when it does display a direction indicator it is locked on solidly. This problem was more pronounced in earlier versions of the S1 firmware and was improved, but not eliminated, in version 2.1. I strongly encourage you to upgrade.

Likewise, sometimes the little man will jump from the line in front of me to the horizontal line at the base of the screen (which means the victim is behind you). I've been told that when the man jumps below the horizontal line, you should either keep walking to see if the numbers increase or decrease, or turn around and follow the man (which should now be in front of you) to see if the distance numbers increase or decrease.

Multiple Burials: Ortovox S1's approach to multiple victims is unique, because the S1 can display multiple victims on the screen at one time. The distance to each victim is also displayed. (The Barryvox S and Pulse can display information on multiple victims, but not in a graphic format.)

Multiple Transmitters

Victim Flagged

Stop Hand

"4+" Screen

"4+" Search

After locating the first victim, you can "suppress" (aka, "mark") that victim by pressing the "Confirmation" button. A flag then appears on the screen where the victim was displayed and the S1 will guide you to the next victim.

Pressing the Confirmation button a second time will unmark the victim. In my testing with two victims, the S1's marking and unmarking were excellent. The user manual mentions that you cannot unmark a victim if several victims are transmitting within a 3 meter radius.

All avalanche transceivers that allow you to suppress a victim must deal with the challenges of overlapping signals. If the S1 is unable to separate the signals and display them on the screen (as might happen when there are 3 or more victims), the S1 will reduce its reception range until the information can be processed and displayed. If the S1 is unable to separate the signals, the "Stop" hand is displayed. You should then stand still as the S1 analyzes the signals.

If there are 3 or 4 transmitters and the S1 is unable to separate the signals, a screen is displayed showing "4+". This screen, although it is far from intuitive, is asking if you want to limit the range to 5 meters. You can then press either the Confirmation or Rejection buttons. After confirming that you want to limit the range to 5 meters, you should then use the expanding circle or micro search strips techniques to locate the victims.

And finally, there is a "Search for more than 3 victims" mode (which can be selected from the menus). In this mode, the first victim is located in the normal manner. After suppressing the first victim, the transceiver automatically reduces the range to 5 meters.

These additional features and icons may be difficult for the average rescuer to deal with during a life-or-death emergency, but the basic search, mark, and locate the next victim features work well.

(Read about multiple burials and transceiver marking on AvyRescue.com.)

Spikes: In my testing, the S1 was good at dealing with spikes.

Controls: You power-on the S1 with the twist of a dial. To change to search mode, you press a release button and flip the lid open.

The S1 makes extensive use of icon-based menus. A few icons were difficult for me to interpret without referring to the user's manual.

You navigate through the S1's menus using two buttons. The bottom button moves through the menu icons and the top button selects the highlighted icon. You can use the pixel-based screen to display a compass, check battery levels, display version information, display an inclinometer, etc. Whether you find the menus and added features helpful or prefer the simplicity of the 3+, Pieps DSPs or Trackers is a matter of personal preference.

On startup (or after changing batteries), you are prompted to calibrate the compass. Via icons, you are prompted to rotate the transceiver, flip it over, and flip it right-side-up. The process is relatively easy, but not intuitive (i.e., when you flip over the transceiver, the screen is no longer displayed to give instructions).

Comfort: The S1's pouch-style harness is outstanding. The shoulder strap is actually labeled "shoulder" to help you sort out the inevitable harness tangle, and the waist strap is non-elastic (my preference, as I dislike the constrictive feeling of elastic around my torso).

At 360 grams, the S1 is 13% heavier than the Pulse, 10% heavier than the Tracker2 and 9% lighter than a DSP Pro. (Much of the variations in weight comes from the harnesses.)

Other

Revert to Send: The S1 will automatically revert to transmit if there is no motion for 90 seconds. This feature can be disabled or changed to 30, 60, or 120 seconds.

Group Check Mode: S1 has a group check mode (Ortovox calls it a "quick test") which also confirms the transmission frequency, transmission period, and period length.

Compass: The built-in compass works well, although it does not allow you to set declination. The compass is not available in the S1+.

Inclinometer: Selecting the inclinometer from the menus displays the angle of the S1's top lid. You can use this to measure the angle of a slope for avalanche evaluation. The inclinometer was designed to be read while the unit is resting on the snow. Unfortunately, you cannot sight along the bottom lid while reading the slope (e.g., to measure the slope of an entire hillside). You can, however, sight along the top lid, press the OK button to lock the display, and then read the slope angle.

A significant disadvantage of using your transceiver to measure the slope is that you'll need to take the transceiver out of its secure pouch and hold it in your hands. If an avalanche strikes, it's likely your partners will unbury your transceiver rather than you. It is far better to use a dedicated avalanche inclinometer app.

Settings: Using the menus, you can change the volume, the amount of time before reverting to transmit, and the screen contrast.

Updates: The S1 has an infrared interface that allows the firmware to be updated. Learn more about updating the S1.

Summary: The S1 has an innovative interface, a good range, good multiple burial features, and handles spikes. Some people may find the menus confusing during an actual avalanche search while others will appreciate the added control they provide. Be sure to read the review of the Ortovox S1+.