Are the ranges as stated in the technical data reliable ?
For reasons of competition, manufacturers tend to state non-realistic search ranges. The 'maximum range' as stated in the technical data may be obtained by objective measurements in many cases, but only holds under absolutely ideal conditions (no environmental noise, strong and accurate transmitter, optimum alignment of transmitter and receiver etc.), that rarely exist in practice. A better approach to compare avalanche transceivers regarding range is the so called 'search strip width'. This value relates to practical use and takes into account all factors that may have a negative influence on the search range, such as low batteries or a frequency inaccuracy on the side of the transmitting beacon, non-ideal alignment of transmitter and receiver etc. The search strip width, as determined by the manufacturer for his device, is printed prominently on the case. The widely accepted method for determining the search strip width was developed by Felix Meier. It is described in detail in the publication 'Determining the Width of a Search Strip for Avalanche Beacons' .
May I use Lithium batteries or rechargeable batteries in my Barryvox ?
Lithium batteries have an advantage over Alkaline batteries by providing much better performance at low temperatures (< 10 deg centigrade). Also, the voltage remains constant until almost the end of the discharging cycle. But this makes it impossible for the built in battery monitor of all Barryvox devices to provide a reliable indication about the remaining battery capacity. It is possible that the Barryvox will indicate an 80% battery capacity when turned on, but the batteries will be empty after 10 minutes of use. Rechargeable batteries (e.g. NiCd- or NiMH acuumulators) exhibit a similarly flat discharge behavior, and in addition they exhibit a notable amount of self discharge. Newly charged batteries will discharge themselves within a few weeks, even if not used at all. Also never insert Carbon – Zinc batteries, since these are completely unusable at low temperatures.
To sum up:
Only use top quality Alkaline batteries from renown manufacturers. Also do not mix batteries from different manufacturers or battteries of different discharging state.
Leaking batteries
Many manufacturers claim that their batteries never leak. Our long term experience, however, indicates that this only holds in very few cases. Near empty batteries are particularly subject to leaking. Leaking battery acid mostly causes irreparable damage that is not covered by the device warranty. Please observe the following precautions:
- only use top quality batteries from renown manufacturers
- keep the battery compartment and the battery contacts clean and dry
- if the transceiver is not used for a prolonged period of time, remove the batteries (e.g. in springtime)
My Barryvox does not transmit although the batteries have checked OK
All avalanche transmitters contain a built-in ferrite rod antenna for radiating the signal energy. This antenna has been precisely tuned to the frequency of 457 kHz. Large metal parts within about 20 centimeters may de-tune the antenna, resulting in a smaller or larger reduction of the transmitted signal strength. On all Barryvox devices, this may lead to a failure of the transmit control LED to blink, even when the device is still transmitting (at a reduced signal level). If the transmit control LED does not blink while in transmitting mode, the most likely reason for this failure is a broken antenna rod. But before you send the device to a service center for a checkup, check the following:
- are the batteries OK ?
- are there any large metal parts near the device or is the device laying on a metal sheet ?
Does my Barryvox operate properly with used batteries ?
If the battery status indication shows that the batteries are still usable, your Barryvox will operate properly. But please note that the transmitter signal strength decreases when the battery voltage decreases. This implies a reduced transmitter range. Therefore, we recommend that you insert new batteries when the capacity has run below 50% at the latest. You will find more detailed information in the section about the respective beacon type.
Pacemakers and avalanche transceivers
Renown manufacturers of pacemakers have checked the Barryvox models VS 68, VS 2000 (Pro) and OPTO3000 regarding a negative influence on the proper functioning of pacemakers. No such influences have been detected, not even when the Barryvox transceiver was transmitting in close vicinity to the pacemaker. Despite these findings, there is no guarantee that this holds for all types of pacemakers and avalanche transceivers.
My Barryvox fell from about 2 meters onto a concrete floor. It seems to operate properly. Does it still need a checkup ?
For reasons of safety, the device should be checked for possible damage by a service center.
The standard EN 300 718 for avalanche transceivers
By European law, avalanche transceivers must not be marketed unless they are in conformance with the standard EN 300 718. This European standard is accepted throughout the world and ensures the compatibility among transceivers from different manufacturers. It guarantees that a 20 years old transceiver from manufacturer A can be located by means of a recently developed transceiver from manufacturer B and vice versa. The standard EN 300 718 states all electrical and mechanical requirements to avalanche transceivers. It also states the environmental conditions under which transceivers must operate properly. The standard can be downloaded from www.etsi.org/services_products/freestandard/home.htm.
Why does the standard for avalanche transceivers not specify a range in meters ?
A given range in meters can be achieved in different ways: A strong transmitter can be paired with a poor sensitivity receiver, or a weak transmitter can be paired with a highly sensitive receiver. But if you pair a weak transmitter with a poor sensitivity receiver, the range is reduced by a significant amount. This is why the standard specifies a minimum transmitter field strength and a minimum receiver sensitivity. This ensures a minimum range among transceivers from all manufacturers. Those requirements also provide the advantage of being measurable by physical instruments. They are independent from any subjective judgment.
Why do avalanche transceivers not transmit an individual code so they can be separated in a multiple burial situation ?
If the radio signal is modified for transmitting an individual code, the nice tone out of the receiver will be replaced by a hiss. Also, the range of such a code transmission would be significantly less than for the analog tone. Transmitting a code without impairing the received tone would require a second, independent frequency allocation. But chances for obtaining another exclusive frequency on an international scale for avalanche beacons are zero. The only way out consists of using a frequency that must be shared with other services.
Why do avalanche transceivers cost that much more than mobile phones even if they provide less functionality ?
The world market for mobile phones is currently (2007) estimated at 1'000'000'000 (One billion !) per year. The world market for avalanche transceivers is currently about 150'000 per year. The factor 1'000'000'000 / 150'000 = ~6'600 makes the difference.