What is Wide-banding/MARS-MOD/Spread-Spectrum?
All are terms for the process of altering a two-way radios factory specifications to enable the transmition or reception of frequencies it was not intended to be used on.
Wide-banding, MARS-CAP, Spread spectrum modifications are a very common occurrence in amateur radio, as licence holders we are among the most privileged users of the RF spectrum. Our licences often allow for experimentation with equipment or parts of the radio spectrum where it would not usually be permitted.
Older equipment sold may have channel spacing out of sync with current recommendations or band limits that do not cover new allocations, so equipment is often altered to expand either the RX or TX to cover the new allocation eg 40Mtrs where the band was extended from 7100Mhz > 7200Mhz or cater for channel spacing eg 2Mtrs where the channel bandwidth was decreased from 25Khz > 12.5Khz.
ISSUES:
LAW-
Radios modified to TX outside their designed specific frequency range can easily conflict with licence conditions or regional regulatory agencies such as the FCC or Ofcom, many countries have very strict guidelines on radio equipment that take a very dim view on alterations.
In some cases, wide banding may be allowed by regulatory agencies, great care following modification of any radio to transmit or receive outside of its intended range could cause interference with other radio services or violate regulatory requirements.
In the UK periodically bands may be temporarily opened up for use, this is known as a NOV (Notice of variation) eg extended regional RF spectrum allocation eg 5Mhz in the UK. Your country may have other schemes unique to it that are very different to the UK.
DAMAGE-
Operating outside of the radios designed frequency range can cause damage to the radio, including the transmitter, receiver, and associated components eg filters.
Poorly modified radios can be irreversibly damaged by inexperienced people or non authorised modifications, band pass filters, PA's are particularly at risk from serious damage if any alteration is carried out poorly or incorrectly. It is important to consult with the manufacturer and/or a qualified technician to ensure that the modifications are made properly and safely.
MARS CAP:
Military Auxiliary Radio System (MARS) Civil Air Patrol (CAP) frequencies. The Military Auxiliary Radio System is a volunteer organisation composed of licensed amateur radio operators who are trained and authorized to provide auxiliary radio communications support to the US Department of Defense and other government agencies during emergencies and special events.
The Civil Air Patrol is a volunteer organisation that serves as an auxiliary of the United States Air Force, providing support for search and rescue operations, disaster relief, and other missions. MARS CAP frequencies are designated for use by these organisations to facilitate emergency communication during times of crisis or natural disasters.
MARS CAP frequencies are authorized for use by MARS and CAP personnel who have been trained and licensed to operate on these frequencies. They are not authorised for use by the general public, and unauthorised use of these frequencies can result in fines and penalties from regulatory agencies.
It is important to follow all regulations and guidelines set forth by regulatory agencies and to only operate on authorised frequencies to ensure safe and legal operation of your radio equipment.
FREEBANDING:
Freebanding is the practice of transmitting and receiving radio signals on frequencies that are not authorised or allocated for a particular radio service. This is typically done by radio enthusiasts or hobbyists who are seeking to communicate with others outside of the authorised frequency bands or to access frequencies that are not available to the general public.
In the context of ham radio, freebanding refers to the unauthorised use of frequencies outside of the allocated ham radio bands. This can include the use of frequencies used by other radio services such as CB radio, marine radio, or aviation radio, as well as frequencies that are not assigned to any radio service.
Freebanding is illegal and can result in fines and penalties from regulatory agencies. It can also cause interference with other radio services and pose a safety hazard if communications are conducted on frequencies used by emergency services such as police or fire departments.
It is important to operate within the authorised frequency bands and follow all regulations and guidelines set forth by regulatory agencies to ensure safe and legal operation of your radio equipment.
CB or 11Mtrs:
Citizen Band, a popular system for truckers and off-roaders around the world, cantered around 27Mhz, restricted typically at 4-12watts is a common reason people opt to modify their radios.
IS LISTENING LEGAL?
In most cases, listening to licensed radio broadcasts is legal. In fact, radio broadcasts are intended to be received by the public, and there are many free services available to listen to licensed radio broadcasts, including traditional AM and FM radio receivers, as well as online streaming services and mobile applications.
However, it is important to note that there may be some restrictions on certain types of radio broadcasts, such as encrypted or proprietary transmissions. Additionally, some countries may have specific laws or regulations regarding the use and monitoring of radio communications, particularly for amateur radio and other specialized radio services.
In general, it is legal to listen to licensed radio broadcasts, as long as you are not interfering with the transmission or attempting to decode encrypted transmissions without proper authorization. Ofcom (here in the UK) give clear guidance that listening to a transmition you are not licensed to use is forbidden unless it is intended for general reception.
If you are unsure about the legality of monitoring a particular radio broadcast or frequency, it is always best to consult with a licensed radio operator or legal professional in your region.
Overall, wide banding ham radios can be risky and potentially harmful to the radio and its operation. It is important to weigh the potential benefits against the risks and consider seeking expert advice before making any modifications to your radio. Ensure you comply with the law in your country and comply with the terms set out in your licence.
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