Broadcast Tower Burnout FAQs

A burnout on a broadcast tower is a situation when all of the power from the transmitter is lost due to an electrical fault, usually resulting in damage to the transmission line or antenna components themselves. This can be due to particulates in the transmission line system, a power surge, or a lightning strike. A burnout can result in low power to a complete off air situation.  Precision Communications offers 24 hour emergency service.

Regular scheduled maintenance including line sweeps and spring tension measurements can help prevent a burnout.  Longer cycle maintenance items such as watchband spring replacement and line cleaning of rigid coaxial line is also recommended. 

In addition to the recommendations to prevent  a burn out, actions such as installing lighting arrestors can protect antenna elements.  Using a constant RF monitoring system such as the Dielectric RFHawkeye can also alert broadcasters of an issue prior to it becoming an off-air emergency. 

Yes, preventive maintenance can help to avoid a burnout on your communications tower. Regular maintenance of your tower and monitoring of its components can ensure that it is running optimally and minimize the chances for a burnout.

If you have a burnout on your communications tower, you should contact a professional technician for help.  Precision Communications has in-house network analyzer technicians to assess issues and make associated repairs to restore full power with your antenna and line.

Common causes of a burnout include particulates in the transmission line system, a power surge, or a lightning strike.

VSWR (Voltage Standing Wave Ratio) is a metric of signal strength which compares forward power and reflected power.  A VSWR of 1:1 is considered optimal as it indicates that all of the power fed into the line is being transmitted. For TV broadcast towers we are looking for readings be 1.1:1  FM can operate with a slightly higher VSWR.

Normally when an antenna system is initially installed, a baseline measurement is taken.  If your VSWR climbs higher than it was upon installation (even if still within industry norms) this indicates the development of an issue and should be investigated.

Most systems include power meters so that transmitters display VSWR in real time.  Regular sweeps of your system are still recommended as transmitter gauge calibration can drift resulting in inaccurate readings. 

Creating an environment with positive air pressure helps keep contaminants and moisture out of your line.  These two items are the cause of most burnouts. 

The first step in repairing a burnout on your broadcast antenna is to identify within your system where the burnout is occurring.   A network analyzer with TDR capabilities can provide this information.  Based on the findings the solution can be as simple as replacing a connector in the transmission line or as complex as a full replacement of your antenna.  Precision Communications has a trailer on standby, complete with hoist and wide assortment of spare parts that is ready to mobilize and support your emergency situation. 

To prevent a burnout when powering up your broadcast transmitter, make sure to gradually increase the power, allowing the system to warm up slowly. Monitor the system carefully while this is happening, and if you notice any anomalies or signs of distress, discontinue the process and investigate the cause. Additionally, ensure that all components in the system are properly rated for the amount of power you will be supplying, and that all connections and circuits are in good working order before attempting to power up.

Yes, technologies like Dielectrics RFHawkeye can monitor for VSWR in real time which will help identify negative trends before they become issues. 

https://www.dielectric.com/rfhawkeye/

The components that typically burn out in a broadcast antenna and line include cracked elbows, fatigued antenna jumpers, or contaminated line connectors.

The cost of repairing a burnout on a broadcast antenna will vary depending on the type of antenna and the extent of the damage.  Based on the findings the solution can be as simple as replacing a connector in the transmission line or as complex as a full replacement of your antenna.  Precision Communications can help provide you pricing in these situations. 

It depends on the severity of the burnout and the technical complexity of the equipment. Generally speaking, it can take anywhere from a few hours to up to a week to get back up and running.  More extreme situations have occurred.