While testing avalanche transceivers this year it has become more evident that older, analog type beacons should be retired. It isn’t because they don’t work. But the way they work can cause trouble in the dreaded multiple victim scenario. If you have more than one person buried in an avalanche the odds are at least one person will turn up dead.Analog beacons should be retired because they transmit with a continuous carrier signal which, when you are close, can confuse searchers by covering up the signals from other, more distant victims. With a continuous carrier signal the oscillator that creates the 457 kHz signal is always on. When the pulse is ON, it connects the signal to the antenna so it radiates in to space. When the pulse is OFF, the antenna is switched off, but the signal is still being generated and it leaks out from the circuit board of the transceiver.
When you are within 2 meters the strength of the signal from an analog beacon is stronger than the ON pulse of another beacon that is approximately 30 meters away. That distance, of course, depends on spatial orientation.
By comparison, with modern digital beacons when they’re off, there is no signal being created. The oscillator circuit that generates the 457 kHz signal is not producing a signal until it is time to turn it on and transmit it. Notice how small the line is between pulses for the digital beacon compared to how fat is is for an F1. The height of the pulse and corresponding lack or presence of it between pulses indicates the strength of the signal between pulses.There is another reason too. Not only is the signal not completely off when it isn’t transmitting, when it is on, it is on for approximately twice the time a current model “digital” beacon is on, which increases the likelihood that there will be an overlap in the timing of signals. This creates another source of confusion for the receiving transceiver, and more importantly, the searcher.
The end result is avalanche transceivers that are great at detecting and helping you find multiple victims, like Barryvox’s Pulse and Element, the Pieps DSP and DSP Tour, and Ortovox’ S1 can become “confused,” which inevitably slows down search times and compromises a victim’s survival chances.
Now I’m not advocating for some rule or law from higher up, I’m just encouraging you that if your avalanche transceiver is an Ortovox F1 Focus, a Pieps 457, or an Arva 457, please upgrade your beacon. You may appreciate it some day, and if you’re caught with another friend they most certainly will appreciate that. And don’t sell ‘em to a stranger either. If you can’t bring yourself to trash it, use it for multiple beacon searches and you’ll see what I mean by how easily it confuses you and others. When you’re frustrated enough, take a hammer to it.
In keeping with that sentiment, this is the last season you can buy an Ortovox F1, but don’t; let someone else make that decision.