*Question G4C02:
Which of the following could be a cause of interference covering a wide range of frequencies?*  

*Correct Answer is  C: Arcing at a poor electrical connection*  

### AI Response: (may contain errors)  

The correct answer to the question is **C: Arcing at a poor electrical connection**. Here's why:

1. **Why the correct answer is correct:**
   - Arcing occurs when there is a breakdown of insulation or a poor connection, causing a spark to jump across a gap. This can generate a wide range of frequencies due to the rapid changes in current and voltage, creating electromagnetic interference (EMI) that can affect many radio frequencies. The chaotic nature of arcing results in a broad spectrum of noise, which can interfere with various communications.

2. **Why the other choices are incorrect:**
   - **A: Not using a balun or line isolator to feed balanced antennas**  
     - While this can lead to some issues like common-mode currents, it typically does not cause interference across a wide range of frequencies. Instead, it may result in specific frequency-related problems.
   
   - **B: Lack of rectification of the transmitter’s signal in power conductors**  
     - This would primarily affect the quality of the transmitted signal rather than create broad-spectrum interference. Rectification issues are more related to distortion at specific frequencies rather than wideband interference.
   
   - **D: Using a balun to feed an unbalanced antenna**  
     - This can lead to inefficiencies and potential radiation pattern issues, but it does not inherently cause wideband interference. The balun is designed to match impedances and reduce common-mode currents, but it does not create the same chaotic noise as arcing.

3. **Useful formulas or rules of thumb:**
   - **Interference Sources:**  
     - Common sources of interference include arcing, switching power supplies, and faulty equipment. Always check connections and equipment for integrity to minimize interference.
   - **Frequency Range of Interference:**  
     - The frequency range of interference can often be estimated by the nature of the source. For example, arcing can produce noise across a wide range, while other issues may be more frequency-specific.

In summary, arcing at a poor electrical connection is the most likely cause of wideband interference due to its chaotic nature, while the other options are more related to specific issues that do not typically result in broad-spectrum noise.