|
 All beacons transmit using one antenna.
The additional antennas are only active while searching at which time they play a significant role.
 |
| Steve Uncovers a Victim |
Single Antennas
Single antenna transceivers typically have a long range when the receiving beacon
is in-line with the transmitting beacon's flux lines, but they have a significant loss in range when the antenna's are not
aligned. Single-antenna beacons cannot display a directional indicator, although some single-antenna beacons do
display a distance indicator.
Dual Antennas
Two-antenna transceivers have two antennas mounted perpendicularly. They compare the relative strength of the signal that is received on
each antenna to calculate the location of the buried beacon. This allows the transceiver to guide you to the victim by displaying a
directional indicator. The two antennas also allow a more accurate
distance to the victim to be calculated and displayed. Two-antenna beacons retain a strong signal even when they
are turned 90°, because the second antenna is then aligned with the transmitting beacon's
flux lines. Two-antenna transceivers, as with single-antenna transceivers, are unable to resolve
spikes.
Three Antennas
Three-antennas transceivers have the advantages of two-antenna beacons (i.e., they can display a directional indicator), plus the third
antenna (which only turns on when you get near the victim) can greatly reduce, or eliminate, spikes (where the beacon mistakenly points
to a location a meter or two from the victim).
More About Multiple Antenna Beacons
The Tracker was the first transceiver with two antennas. It quickly gained
the reputation as the easiest avalanche beacon--it certainly was. Yes, some professionals discounted the Tracker as being for novices, but ease-of-use is
 important
when your best friend is dying. The Tracker uses its two antennas to point you toward your buried friend. The ARVA Advanced,
ARVA Evolution+, and the Barryvox 3000
also have two antennas and as with the Tracker, these beacons will quickly lead you to the victim. The Ortovox X1 also
has multiple antennas (either two or three), but in my testing it performed relatively poorly.
| Advertisement |
Shovel System |
The Ortovox S1, Pulse
Barryvox, Pieps DSP and Pieps DSP Advanced have three
antennas. These avalanche transceivers not only offer the directional and distance benefits of two-antenna beacons, but they almost eliminate
spike problems. You will not notice the spike handling when searching for a beacon a few inches under the snow (as is typical during practice),
but bury it under a meter or two of snow and the difference is significant. The three antennas allow an antenna on the receiving beacon to be pointed in three-dimensions (i.e., up/down,
left/right, and forward/back). The beacon can then use the relative strength of the signal on each antenna to precisely locate the transmitting beacon. The
Ortovox D3 and newer Ortovox X1s also have three antennas,
but in my testing they failed to eliminate spikes. The DSP (and probably others) has a 4th antenna that is only used during its self test.
In my testing, having two-or-more antennas is the most important factor in performing a rapid
secondary search in all conditions with a variety of experience levels. And three-antennas greatly improves the
pinpoint search in all but very shallow burials. I know some old-timers will disagree, but only until they do serious
tests with a multi-antenna transceiver. I was a hardcore Ortovox F1 fan and swore that multiple antenna transceivers
were for dummies--until I used one and discovered the benefits. That isn't a sales pitch, rather it is based on my experiences with many beacons.
Learn more about multiple antennas and spikes here
 (of course, this isn't necessary if you have a three-antenna
avalanche transceiver).
|
