Does your business depend upon monitoring radio transmissions, but you do not have the budget to hire an employee to test and ensure your reception is as clear and vast as it can be?  Site Survey America LLC is a network of the most experienced and equipped RF technicians in America with the know-how to map the right reception equipment, locations, and technology to achieve the results you need.


A Case Study: Receiving Cleveland Ohio Public Safety Fire Transmissions

Image by Ryan French, RF Technician

Introduction

Public safety radio is often monitored by companies that wish to respond when tragedy strikes a home or business in order to assist those in need to get their lives and property back in order.  The challenge the company faced included monitoring a complex radio system where multipath propagation and simulcast distortion is a real challenge.  Upon sourcing a RF technician from Site Survey America, problems that plagued this organization for years were resolved in a matter of days.

Reception Challenge

For years this emergency response company attempted to receive the Cincinnati public safety radio system.  Understanding that the Hamilton County frequencies are completely separate from the city frequencies, and being physically located close to the public safety facilities associated with Cincinnati, the company believed strongly that reception should be easily achieved.

The frustration came to a head after trying everything possible to receive the transmissions originating from the city.  After hiring a full time employee to address the continued reception challenges, and then having to release the employee when the results were not satisfactory, Site Survey America was engaged to take on this perplexing challenge.

Overall, most of the jurisdictions of Hamilton County operate off the Cuyahoga County tower sites of the Ohio statewide MARCS system.  Only two operate off the City of Cleveland radio system. Both radio systems are digital Project 25 Phase I simulcast systems. These systems can be very tricky to receive due to the technical limitations of the technology inside radio scanners.

Radio Reception Survey Evaluation

The RF engineer first evaluated the equipment located on premise, which included (3) Uniden Bearcat BCD536HP scanners running off an inside antenna. These scanners were programmed to Cleveland and the technician noticed the reception of the system was sporadic at best and therefore few transmissions were received. Furthermore, the scanner radios had serious difficulty locking onto and decoding the control channels associated with the Cleveland trunked system.

Using a radio spectrum analyzer, the RF engineer was able to visualize the signals being received, specifically the 700/800 Mhz band.  It was quickly obvious that there was significant amounts of noise (interference) in the signals, and those radio signals that were received were weak.  The radio technician believed that the noise was generated by the antenna and multicoupler located adjacent to an electrical conduit, which could cause such interference.

Improving reception for the Parma radio system in Ohio

Evaluation of equipment located on the second floor included three Uniden Bearcat BCD996P2 scanners connected to two antennas:  A Yagi and a Diamond Discone antenna with (2) scanners connected to the Discone and (1) off the Yagi.  This equipment was designed to receive the Parma radio system in Ohio.

Through further testing, the tech determined the Yagi on premise was the proper antenna to receive Parma, but due to it being directed incorrectly, reception was poor.  With proper adjustments, a reliable lock onto the control channels for MARCS and Cleveland was achieved.

That evening, the RF technician continued to monitor the system to ensure nothing changed as time of day, weather, temperature, and other factors can have a significant affect on reception of radio signals.

Improving reception for the Lorain County radio system in Ohio

The second day the technician evaluated their second installation in Elyria Ohio.  At this location, the client was using (4) Uniden Bearcat BCD996P2 scanners with a Discone antenna.  All agencies in this county utilize conventional VHF/UHF channels.  The client stated that this part of the system functioned well and just wanted a checkup, although he did note one agency, North Ridgecrest, was received poorly.

After extensive testing the tech advised that a 10 foot mast will clear up that agency reception.

Upon returning to the Cleveland location, the technician fine tuned the reception of the radio scanners located at this site.  Approximately 90% of the transmissions were crystal clear and readable.

Site Survey Reception Recommendations

(1) Recommend the client elevate their antennas at both locations:

The Discone antennas at both locations were only a few feet off the roof line.  The Yagi at the Cleveland location was only a couple of feet off the roof.  Elevating the antennas will increase the line of sight and would result in better reception.

Although the Discone antennas can be elevated with ease, extreme caution is to be used when adjusting the Yagi.  As noted above, it is a directional antenna and specifically pointed Southeast.  Even a few degrees variance may be enough to cause reduced or loss of reception of the City of Cleveland and/or the MARCS Cleveland system.

(2) The Cleveland location:

Recommend client replace a Uniden Bearcat BCD996P2 scanner with the Uniden Bearcat BCD536HP scanner, as well as program this location is for Cleveland and MARCS.  The addition of this scanner will improve issues with multipath interference and address the duplicate transmission problems previously observed by the client.

(3)  Suggested hardware changes to improve radio reception

At the client’s Cleveland location, the technician recommended using a Stridsberg Engineering MCA804B multicoupler with BNC connectors.  This multicoupler will use the Yagi antenna feed, and then connect to the (4) Uniden Bearcat BCD536HP scanners covering Cleveland and MARCS.  Since these scanners are 700/800mhz only, a multicoupler will filter out unwanted noise from other bands and boosts signal strength.  Currently the multicoupler connected to the scanners scanning this site is the (4) port Stridsberg Engineering MCA204M.  The tech instructed the owner on how to swap the multicoupler if they decide to order the MCA804B.

The tech instructed the owner on how to swap the multicoupler if they decide to order the Stridsberg MCA804B.

Conclusion

If the recommendations in this report are followed, the client’s reception capabilities will improve substantially.  Of the total 326 frequencies being monitored, only 232 were being received.  Upon completion of this radio site survey, RF testing and equipment improvements sat each location resulted channel capture to a full 100%, or a total of 326 channels received.


Is your business looking for this type of results from your radio monitoring system?
Contact Site Survey America and let our RF technicians solve your reception problems for good.

SSA Logo Test radio reception USA