Chpt 9 - Safety
Observing good safety practices around your ham shack and antenna system is a must! These are excellent links to have handy at any time, not just when you’re studying for your license.
These are excellent links to have handy at any time - not just when you're studying for your license! The need for safety never goes away...
RF Exposure Evaluation – a guide to evaluating your station
Mobile installation – from KØBG’s Mobile Operating Web site
Antenna and tower installation – from Universal Radio
RF Exposure and You – the ARRL’s printed reference guide
The ARRL Handbook – refer to the Safety chapter
The ARRL Antenna Book – specific information on antenna and tower installation
National Electrical Code - the master reference for electrical safety
Up The Tower by K7LXC – how to install and maintain antennas and towers
There are several different standards for defining electrical shock hazards, depending on the environment in which the standard is applied. For example, current leakage standards in medical equipment are different than for home appliances and those standards are different than on-the-job industrial standards. The table used in the HRLM is from OSHA Publication 3075, "Controlling Electrical Hazards" (www.osha.gov/Publications/3075.html).
The Wikipedia article on electric shock (en.wikipedia.org/wiki/Electric_shock) states, "A low-voltage (110 to 220 V), 50 or 60-Hz ac current travelling through the chest for a fraction of a second may induce ventricular fibrillation at currents as low as 60 mA. With dc, 300 to 500 mA is required. If the current has a direct pathway to the heart (e.g., via a cardiac catheter or other kind of electrode), a much lower current of less than 1 mA, (ac or dc) can cause fibrillation. Fibrillations are usually lethal because all the heart muscle cells move independently. Above 200 mA, muscle contractions are so strong that the heart muscles cannot move at all."
The discussion of how to calculate average power has been clarified with new text as shown in the companion errata document for the 1st printing of the text.