What is the recommended Tx Line Bonding Distance?

• A. Install at midpoint to reduce distance to 200 ft or less; in lightning-prone areas 50-75 ft
• B. Install at one end; distance up to 400 ft
• C. Bond every 300 ft
• D. No bonding distance specified

Answer: (A)

The key idea is how far apart bonding points should be on a transmitter (Tx) line to keep the line at a consistent electrical potential and provide a safe, low-impedance path for surges and RF currents. Bonding at the midpoint is the best approach because it minimizes the maximum distance from any point along the line to a bond. When the line is bonded in the middle, each half is limited to about 200 ft or less, which reduces the chances of large voltage differences along the line during lightning or surge events and helps keep RF currents well-controlled.

In areas prone to lightning, shortening that distance even further to about 50–75 ft improves protection by reducing inductance and the potential loop area that surge currents can travel through. This tighter bonding reduces the likelihood of damaging arcing or RF grounding issues.

Other options fall short because bonding at only one end can leave up to 400 ft of line unbonded, increasing susceptibility to voltage differences and adverse surge effects. Bonding every 300 ft introduces multiple bonds, which isn’t the standard practice for this scenario and isn’t necessary when a midpoint bond already provides the required protection. Saying no bonding distance is specified would neglect an explicit guideline designed to manage these risks.