Group T0C: RF hazards Flashcards
RF hazards: radiation exposure, proximity to antennas, recognized safe power levels, radiation types, duty cycle
What type of radiation are radio signals?
Non-ionizing radiation
At which frequency does maximum permissible exposure have the lowest value?
50 MHz
How does the allowable power density for RF safety change if the duty cycle changes from 100 percent to 50 percent?
It increases by a factor of 2
What factors affect the RF exposure of people near an amateur station antenna?
All these choices are correct
- Frequency and power level of the RF field
- Distance from the antenna to a person
- Radiation pattern of the antenna
Why do exposure limits vary with frequency?
The human body absorbs more RF energy at some frequencies than at others
Which of the following is an acceptable method to determine whether your station complies with FCC RF exposure regulations?
All these choices are correct
- By calculation based on FCC OET Bulletin 65
- By calculation based on computer modeling
- By measurement of field strength using calibrated equipment
What hazard is created by touching an antenna during a transmission?
RF burn to skin
Which of the following actions can reduce exposure to RF radiation?
Relocate antennas
How can you make sure your station stays in compliance with RF safety regulations?
By re-evaluating the station whenever an item in the transmitter or antenna system is changed
Why is duty cycle one of the factors used to determine safe RF radiation exposure levels?
It affects the average exposure to radiation
What is the definition of duty cycle during the averaging time for RF exposure?
The percentage of time that a transmitter is transmitting
How does RF radiation differ from ionizing radiation (radioactivity)?
RF radiation does not have sufficient energy to cause chemical changes in cells and damage DNA
Who is responsible for ensuring that no person is exposed to RF energy above the FCC exposure limits?
The station licensee
