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Intra Everest communication
17:48 p.m. EST Apr 28, 2004
For communicating back home from Everest, either via data or voice, the satellite phones and IP modems are king. However, for communicating on the mountain itself with climbers, Base Camp, and other teams, the VHF radio rules.
Fixed and Handheld units
On the North most teams have a fixed radio with an aerial in both Base Camp and Advanced Base Camp. On the South, fixed radios can be found in Base Camp and even in Camp II sometimes. At the beginning teams select a frequency and then typically stick to it – with climbers carrying handheld VHF units and using them to communicate back to Base Camp. With some handheld units, you can key in frequencies with a built in touch pad, but with others you need a computer to preset a certain number of channels. The ones with the built-in keypad are much easier, albeit sometimes more expensive.
Up, down, and around
There are a lot of options out there in terms of VHF radios, power, and transmitting frequency range. The easiest way to describe it is to compare the VHF frequencies to the Wifi Internet setups that are exploding everywhere. The two main setups are 802.11b and 802.11a. B transmits in the 2 ghz frequency and A transmits in the 5 ghz frequency. B doesn’t have as long as a range, however, it can go around corners. A, can go much farther in a straight line, but has problems going around corners.
On Everest, nothing is in a straight line; well, maybe the Russian North Wall direct team is. For the rest of the climbers, on the North as well as the South side, the route snakes left and right, and certain parts of the mountain break line-of-sight between climbers and Base Camp. Because of this, VHF transceivers that are capable of transmitting in the lower frequencies, like the 802.11b Wifi setup, with high wattage, are the best bet – they have the ability to make it up, over, and around.
Pick the right range
Some units transmit on a broad range, while others, only a narrow band. The most common range for Everest is in the 140’s Mhz range, with most teams coming in between 144.000 Mhz and 147.990 Mhz range. A fixed transceiver in Base Camp with 50 Watts of transmitting power is enough for North side teams to hear the South Side Base Camp and vice-versa. The handheld units don’t quite make it over though, so when you hear a conversation from the other side, it’s usually only one sided – the guy with the fixed transceiver.
Out in the cold
Be careful when buying a transceiver and antenna combo, they work together in terms of frequency range – also, if you have a unit that will only transmit in the 200 or 400 Mhz (UHF), you’ll be out of touch with the rest of the mountain. Scanning through and knowing the frequencies of other teams is a good way of finding out what is happening on the mountain and is also extremely useful should a rescue need to be coordinated. Be in touch!
VHF communication is vital for climbers, both in understanding the condition of the route, what is going on where, what has been fixed, etc. . . Satellite phones can be used as well, however, the cost of a VHF conversation is the amount of power it consumes, be it from solar, generator, or battery power. Satellite phone calls, however, cost one to several dollars a minute.
ExplorersWeb image of a fixed VHF unit in Everest Base Camp.
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