What is Wide-banding?

Wide-banding or MARS-MOD is the process of modifying a radio to transmit outside its originally designed frequency range. This is often done to allow amateur radios to operate on other services such as MARS (Military Auxiliary Radio System) or CAP (Civil Air Patrol).

LAW Issues

Modifying a radio for wide-banding may violate your licence conditions. In the UK, Ofcom regulates radio communications and any modification that causes the radio to operate outside its type-approved parameters is illegal. NOVs (Notices of Variation) in the UK allow certain exceptions but wide-banding is not typically covered.

DAMAGE Risks

Wide-banding can damage your radio in several ways: the transmitter may produce spurious emissions, the receiver may become desensitised, the front-end filters may be overloaded, and the power amplifier may be damaged by operating into a high SWR on frequencies it was not designed for.

MARS CAP Explained

MARS and CAP are US organisations that allow amateur radio operators to communicate on certain military frequencies during emergencies. Some operators modify their radios to access these frequencies.

FREEBANDING Explained

Freebanding refers to operating on frequencies between the amateur radio bands and CB radio (11 metres) without a licence. This is illegal in most countries.

CB / 11Mtrs

CB radio operates on 27 MHz (11 metres) and does not require a licence in the UK. Some modified amateur radios can operate on these frequencies but doing so with a modified radio is likely illegal.

IS LISTENING LEGAL?

Ofcom guidance on listening to transmissions can be found on their website. Generally, listening is legal but acting on what you hear or transmitting without authorisation is not.

Conclusion

Weigh the benefits of wide-banding against the risks. Seek expert advice and always comply with the law in your jurisdiction.