The Society of Broadcast Engineers

The Association for Broadcast and Multimedia Technology Professionals

Advanced RF Series RF 201: Module 7: FM Filters and FM Combiners

Instructional Method: Available ON DEMAND


FM stations sharing common infrastructure, towers and antennas, have challenges to overcome in order to be compliant with the FCC’s 47 CFR Part 73 rules, 80 dB suppression from the carrier amplitude, regarding out of licensed channel emissions. Coupled energy between transmitters can cause unwanted intermodulation products that exceed those rules. FM filters have been designed to eliminate the creation of those products in both small and large systems. Design aspects of filters will be discussed including the use of loops, iris and direct couplings. This webinar will cover the types of filters used such as notch and bandpass filtering. This presentation will also address the use of commonly used technologies for emissions control and channel combining for shared antenna systems. Custom filter solutions will be covered that isolate FM signals from AM towers and combine analog FM and digital IBOC when transmitter technologies are not used.

Advanced RF: RF201 Webinar Series

  • Module 1: FM Transmitters, ON DEMAND
  • Module 2: FM Antenna Systems, ON DEMAND
  • Module 3: AM Directional Antenna Systems, ON DEMAND
  • Module 4: Transmitter Site Grounding, ON DEMAND
  • Module 5: Television Transmitters, ON DEMAND
  • Module 6: RF Systems Diagnostic Measurements, ON DEMAND
  • Module 7: FM Filters and FM Combiners, ON DEMAND
  • Module 8: AM Multiplexed Antenna Systems, ON DEMAND
  • Module 9: TV Combiners, ON DEMAND

About Your Instructor: Tom Silliman, President, ERI

Tom Silliman, PE, is president of Electronics Research, Inc., in Evansville, IN. Tom’s engineering career started when he was 14 years old. He holds a Master of Electrical Engineering from Cornell University. He played Lacrosse at Cornell, both freshman and varsity. Tom designed the ERI Roto-Tiller side mount antenna, the most used FM antenna in the United States in 1975. He is certified in rescue and climbing safety as well as a world-class water kayaker and a certified Indiana Master Gardener.

Nicholas Paulin, Engineer, ERI

Nicholas Paulin is currently an engineer with Electronics Research, Inc. He has worked in multiple areas of ERI’s broadcast transmission business including engineering and design of FM radio and Television antenna systems and of channel combiners for FM and TV applications. He spent the peak years of the digital television transition, a period of high demand and urgent delivery requirements, working at ERI’s Gray Maine manufacturing facility producing Television filter and multiplexer systems. Nick currently manages engineering for ERI’s Television and FM Radio Filter and Component Products. Nick has been instrumental in introducing new products such as ERI’s Shared Aperture FM Antennas, low-power FM and TV filters, and the FM All Pass Filter. He is a graduate of Purdue University holding a B.S. ECET and is a member of IEEE.

Robert Rose , VP, ERI

Robert Rose started as a detailer at ERI and helped complete the One Shell Plaza FM Master Antenna project in Houston, Texas.  Later, Robert became an accomplished RF technician.  He is now a Vice President at ERI with 50 years of design experience.  He was responsible for the design of our current FM filter products as well as the lead designer for our broad band side mount FM antenna product, the ERI Axiom.

SBE Recertification Credit

The completion of this webinar from Webinars by SBE qualifies for 1 credit, identified under Category I of the Recertification Schedule for SBE Certifications. 

Registration and Pricing   

Registration for each module will be done separately. Click Register Now below, to register for Module 3.

SBE Members: $62

MemberPlus Members: FREE

Non-Members: $92

SBE MemberPlus members – when registering, be sure to click on the MemberPlus link to activate your MemberPlus benefit to register for free. Not a SBE MemberPlus member? For more information, see below.

Register Here


If you have questions regarding this webinar, contact Cathy Orosz via email or by phone at 317-846-9000.

More information about registering using the SBE MemberPlus benefit

The RF 201 Series and all new SBE webinars presented in 2020, are included at no additional cost for members who renew or join using the $175 SBE MemberPlus membership option. You get all RF 201 modules, plus access to all archived SBE webinars and any new live webinars SBE presents through March 31, 2021, all for no extra cost. Members can renew and newcomers may join online at the SBE website using the SBE MemberPlus option.

Access to the SBE webinars through the SBE MemberPlus program is limited to the MemberPlus-purchaser only.  You are not permitted to distribute, sell, copy, share, project or otherwise make the webinars available to any other individual or group without express written permission by the SBE.