Cutting through interference – Amateur and Citizen Band (CB) Radios

Radio equipment used in the amateur radio service and Citizen Band (CB) operates under a no-interference, no-protection policy.

• no interference: You must not cause interference to any other radiocommunication services operating within the same frequency band.
• no protection: You have no entitlement to protection against harmful interference from other radiocommunication services operating in that band.

Amateur radios do not require certification from Innovation, Science and Economic Development Canada (ISED). However, operators must obtain an amateur radio operator certificate and operate their radio station in accordance with RBR-4 — Standards for the Operation of Radio Stations in the Amateur Radio Service.

In contrast, for CB radios, you must use a device that is certified by ISED. A certified CB radio will have an IC number displayed on the device label. These radios have fixed frequency channels that you can select using external controls on the device. Using an amplifier to increase the output power of a CB radio transmitter is prohibited due to the potential for interference. Before using a CB radio, you should familiarize yourself with the information provided in circular RIC-18 — General Radio Service (GRS).

If you are experiencing interference, you can take steps to identify the source of the interference, and mitigate its effects.

Check your components

Every component of a radio station must be properly installed and verified to ensure compliance with all technical standards. CB stations are required to use certified equipment that adheres to ISED Radio Standards Specifications (RSS-236). Modifying any certified equipment will invalidate its certification.

If changes are made to the installation, the technical performance of the station must be re-evaluated to ensure continued compliance with ISED requirements.

Ground your equipment

All radio station equipment, including antennas, must be properly grounded and should have a separate grounding system from the home's AC electrical distribution system. If these grounding systems are not kept separate, reflected radio frequency energy in the form of standing waves can be transmitted into the building's electrical wiring and the neighbourhood's power distribution lines.

A proper grounding system consists of a copper rod buried at least 2.4 meters deep into the ground, as frost can penetrate as deep as 1.2 meters. Additionally, the ground wire should be made of copper tie wire that is at least No. 12 gauge. It's also advisable to keep both your radio and antenna as far away as possible from neighbouring TV or FM antennas and areas where gaming consoles, computers, hi-fi stereos and similar equipment are used.

Enclose your equipment

Every radio device should be housed in a cabinet or enclosure specifically designed for it. This cabinet ensures proper shielding of the electronic circuits and components. All parts of the cabinet should be securely fastened, with screws tightened properly.

Check your antenna

An incorrect antenna type or improper installation can significantly contribute to interference. If the antenna's length is not correctly matched to the transmitter, it may generate unwanted signals that can be transmitted more effectively than the desired signals.

To minimize potential interference issues, position your radio station's antenna as follows:

• place it as far away from neighbouring houses as possible, and ideally higher than them.
• position it away from power lines that could disrupt its operation.
• keep it distanced from any telephone, cable television, or television antenna cables.
• ensure it is as far away from electronic equipment as possible.

It is not advisable to install a transmitting antenna in an apartment or on an apartment balcony. Fixed antenna systems must comply with the requirements outlined in CPC-2-0-03—Radiocommunication and Broadcasting Antenna Systems.

An antenna transmission line carries radio frequency energy between a transmitter or receiver and an antenna. High-quality coaxial cable is often used for this purpose. Coaxial cable is designed to transmit high-frequency electrical signals with minimal signal loss and interference.

When selecting and installing coaxial cable for the transmission line, it is important to follow the manufacturer's instructions carefully. Ensure that the transmission line is securely fastened and avoid placing it close to or parallel with telephone wires, cable TV lines, or television antenna cables. Do not puncture, flatten, or bend the cable sharply. Additionally, make sure that all outdoor connections are well-sealed to prevent water from entering.

Use Radio Filters

Filters are highly recommended for fixed radio station installations to reduce interference caused by out-of-band emissions. This is particularly important for co-located sites with multiple transmitters. Filters can also eliminate spurious emissions from your transmitter, which may interfere with other users.

The two most common types of filters are:

• band-pass filters: These filters allow signals within a specific frequency range to pass through while reducing signals outside that range.
• notch filters: These filters significantly reduce signals within a narrow frequency range while allowing all other frequencies to pass through unchanged.

It is advisable to consult your radio equipment supplier or manufacturer for suitable filters.

Adjust your transmission signal

If your equipment is functioning properly and you have installed a filter but are still experiencing interference, try lowering the power level of your transmission. Additionally, you can use a directional antenna to focus the transmitted energy either towards or away from a specific direction.

Certain situations may require assistance from ISED's Spectrum Operations district offices to investigate or resolve interference.

While interference can certainly be a nuisance, not all interference is considered harmful. In fact, many consumer devices must accept interference, as may be written on their label or in their manual.

ISED focuses its efforts on investigating harmful interference, that which:

• endangers the use or functioning of a safety-related radiocommunication system (such as police, fire, ambulance, and aeronautical services)
• or significantly degrades, obstructs, or repeatedly interrupts the functioning of radio apparatus, or radio-sensitive equipment (non-radio electronics).

ISED does not usually investigate non-harmful interference unless there is suspicion of regulatory non-compliance.

Reporting Interference

ISED does not investigate general household or business interference. Instead, it focuses on investigating interference that impacts public safety communications.

If you believe radio interference is severely impacting these critical communications, you should contact your nearest ISED Spectrum Management district office. They will review the information you provide, determine whether the interference is harmful, and take appropriate action to identify and resolve the issue.

If you are a public safety agency (such as police, fire, emergency medical services, the Canadian Coast Guard, or the Department of National Defence – Search and Rescue), please refer to CPC-3-13-03 — Interference Resolution Services on a 24/7 Basis for Public Safety Agencies for important additional information.