The bhi Ground Breaker audio isolation unit is a simple solution to RFI and ground loop audio breakthrough problems
Introduction RF breakthrough and earth loop current problems tend to happen when a transceiver is in transmit mode (keyed). You will hear a buzz or your own distorted voice coming out of the audio. The main reasons are a poorly matched antenna or a difference in ground currents between pieces of equipment. RFI issues are usually caused by reflected waves coming back down the outside of the coax whilst earth loop problems are usually caused when the same power supply for the radio and “add-on” audio equipment is being used. The bhi GroundBreaker is a quick and easy solution for this issue as it isolates the grounds of your external audio equipment from those of the radio system and prevents earth ground loops and associated RFI problems from getting into your audio. The bhi GroundBreaker is easy to install and simply fits in between your radio and audio equipment.
Installation The bhi GroundBreaker is easy to use and simply connects between your radio and audio DSP/ancillary equipment using 3.5 mm connections. It can also be used to isolate headphones when plugged into the headphone socket on the radio or extension speaker..
Balanced to Unbalanced audio systems Most audio amplifiers used in radios are Class A or AB. They normally have a single ended (unbalanced output that works against ground, however, recently some manufacturers have started using balanced audio amplifiers and Class D (switch mode) amplifiers. These present a different problem as most audio ancillary products on the market (unless they are for professional audio) use unbalanced inputs. The GroundBreaker can be used to isolate the balanced audio output of the set and allow the ancillary unbalanced input to be unaffected.
Maximum Power Handling The GroundBreaker does have limits to its power handling. The 600 Ohm and 10k Ohm devices are capable of handling the normal audio levels that can be found in most audio systems. The 8 Ohm units are only meant to be used at powers up to 0.5 Watts input. This allows interfacing to most bhi DSP audio products and is not meant for the transfer of power into un-powered speaker units.
