HF RADIOS
The IFRC use HF radios in some of its vehicle and bases.
This section only covers vehicle mounted radios.
HF radios are installed in some vehicles to help drivers communicate with the radio room during longer range range field missions. While most staff and volunteers will not regularly use HF radios, it is important that they know how use it in case of emergency (e.g the drivers is incapacitated in an accident).
This section only offers basic instructions - to allow personnel to make an emergency call.
Using a HF radio (installed in a vehicle)
1. Turn the power on.
2. Select the right channel.
3. Press the call button and wait for the radio room to pick up (like a phone call).
4. Press and hold the talk button. When you press the button, wait one second before you start talking.
5. Release the talk button to listen.
IMPORTANT! When you get into a vehicle with an HF radio, ask the driver if it works, what the range is, and what channels are used. If you need to make an emergency radio call, you will need this info.
How HF waves travel
HF radio waves are a combination of groundwaves (direct line of sight) and skywaves (reflected by atmospheric layers).
Due to the skywaves, HF waves can travel much longer distances than VHF waves and are less affected by geographical features. Under ideal conditions, the signal range is thousands of kilometers.
Be aware that when your move approx 15-50 km away from the transmission site (radio room), you can can enter the “skip zone”. This is when you are beyond the range of groundwave and the skywave is bouncing over your position. If you cannot connect, try moving to a higher location or outside the skip zone.
The HFR signal is also affected by solar activity. Therefore, quality of reception can vary depending on the time of day and can also differ between days. These are factors that are out of your control but you should familiarize yourself with the radio coverage in your area of operation by mapping out potential spots where the coverage is inadequate. This is done by conducting radio checks while travelling in the field and marking on a map those areas where there are blind spots or no reception.
If you have problems, try this:
Check you’re on the right channel and that the volume is up.
Move to a higher location.
Change locations. You might be in the skip zone.
Other things to consider
HF communications can be monitored by others, so think before you speak. Don’t share confidential information.
RADIO ROOMS
The term ‘radio room’ is often used when referring to the country delegation’s operational communications centre. All delegations and Federation offices must establish a system or procedures to monitor delegates’ field movements. In larger operations, this can be done by establishing a radio room with radio room operators. In small delegations, it could be someone in the administration office who is responsible for monitoring field movement.