Measure the resistance value with ohmmeter between the jumper AC plug and each exposed metal cabinet part, such as screw heads, antenna, control shafts, handle brackets, etc. Equipment with antenna terminals should read between 3MΩ and 5.2MΩ toall exposed parts*. (Fig 1) Equipment without antenna terminals should read approximately infinity to all exposed parts. (Fig 2)
*Note: Some exposed parts may be isolated from the chassis by design. These will read infinity.