Overview

Incorporated by Doug Allen in 1965 to serve the growing broadcast industry, providing engineering services to help clients establish and operate broadcast facilities throughout Canada.

Services

D.E.M. Allen & Associates Ltd. provides planning, design, supervision and adjustment of broadcast transmitting facilities; including specifications, tender evaluation, and preparation of reports and technical briefs for federal regulatory bodies.  The company also offers evaluation and measurements associated with radiofrequency (RF) propagation and electromagnetic energy throughout the radiofrequency spectrum.

Fields of Specialization

• AM, FM, HD IBOC and DTV broadcast facility design, licensing and certification
• Co-location of mobile (cellular) communications and broadcast facilities
• Microwave communication systems
• Millimetre wavelength RF distribution and two-way interactive systems
• RF measurements and evaluation related to Supervisory Control and Data Acquisition (SCADA)
• Electromagnetic Compatibility (EMC) and Electromagnetic Immunity (EMI) including high level RF energy evaluation and measurement
• Safety Code 6 compliance prediction and measurements
• Induced and Contact Current Measurements
• Terrestrial Satellite Digital Audio Radio Service
• Interference and Re-Radiation analysis and mitigation
• Method of Moments Modeling of AM arrays and reradiation studies
• Radio Frequency Interference measurements of Substation and Transmission Line Facilities

Sample of Completed Projects

• Design and adjustment of many 1 kW to 50 kW AM broadcast facilities all across Canada
• Preliminary, Final and Supplementary Proofs of Performance for AM broadcast facilities
• Design of specialized phasing and matching networks for co-located and diplexed AM broadcast facilities
• Planning and design of more than 50 FM broadcast transmitting stations across Canada
• Planning and design of multi-hop microwave systems for TV transmission
• Technical briefs for 54 mandatory DTV conversions to facilitate August 31, 2011 conversion milestone in Canada.
• Licensing for conversion of TV microwave STLs to accommodate DTV conversion
• Measurements/listening tests for 2nd-adjacent FM station
• Completed Safety Code 6 measurements and reporting for broadcast sites, building rooftops, condominium developments
• Elliptical polarization analysis for antenna selection for DTV conversion
• Synchronous FM analysis for coverage improvement in terrain-limited environments
• Site selection and coverage prediction for DTV conversion planning in Caribbean
• Design of temporary broadcast facility to facilitate continued operation of existing broadcast operations during facility rebuild and antenna replacement.
• Digital Audio Broadcasting(DAB) rollout analysis and plan.
• Design and feasibility analysis of co-siting cellular transmitting facilities on AM broadcast transmitter sites.
• Studies to determine the impact of wind turbine generating systems on communication and broadcast facilities
• Safety Code 6 studies at a multi antenna satellite uplink facility
• Studies and analysis of power lines, towers and other re-radiating objects within the vicinity of AM broadcast transmitter sites
• Study to determine the impact of water storage tanks on local communication facilities
• Design, specification, and commissioning of a wireless SCADA system for a major water utility.
• Design and specification of Multi-point distribution systems operating at 2.5 GHz
• Specification and acceptance testing for the multi-station FM combiner at Master FM on the CN Tower, Toronto, Ontario as well as at the multi-station facility at Camp Fortune, Ottawa, Ontario