What device can be used to cure distorted audio caused by RF current on the shield of a microphone cable?

• A. Audio filter
• B. Ferrite choke
• C. Shielded cable
• D. Low-pass filter

Answer: (B)

A ferrite choke is effective in curing distorted audio experienced in microphone systems due to RF current on the shield of the microphone cable. This device works by introducing a magnetic core around the cable, which suppresses high-frequency noise and RF interference that can couple into the audio signal. When RF currents pass through the cable, the ferrite material impedes those frequencies while allowing the audio frequencies to pass through unhindered, thereby preserving audio integrity.

While audio filters and low-pass filters can help reduce unwanted frequencies, they might not be specifically tailored to address RF interference, which is the primary culprit in this scenario. Shielded cables are also beneficial as they provide an additional barrier against interference but may not completely eliminate the issue of RF currents if they are already present on the shield. Thus, using a ferrite choke effectively targets the specific problem of RF interference on microphone cables, making it the correct solution.