High frequency interference of radio signals can be limited by

• A. Using longer cables
• B. Using low welding amperages
• C. Ensuring the power source is properly grounded
• D. Suspending the welding cables above ground

Answer: (C)

High frequency interference from the TIG HF starter can radiate along welding cables and into nearby radios and electronics. Providing a solid grounding path gives the welding system a low-impedance return and stabilizes the electrical potential, which suppresses stray RF currents and reduces the amount of energy that can couple into external equipment. In practice, a well-grounded power source shunts the HF energy away from the cables and environment, cutting down radiated interference.

Longer cables tend to act as antennas and can increase interference rather than limit it. Using low welding amperages doesn’t directly address the RF energy leaking from the HF system. Suspending cables above ground can also increase their tendency to radiate. Thus, proper grounding is the most effective measure to limit high frequency interference.