KGOU

tropospheric ducting

Fuzzy Signal Explained

Jun 17, 2017

This is the Manager’s Minute.

Every spring, summer, and early fall, generally in the mornings, listeners may occasionally experience a fuzzy or noisy signal. Our transmitters and your radio are fine – this disruption is caused by tropospheric ducting, also called temperature inversion.

When the air gets warmer in higher altitudes and cooler in lower altitudes, this atmospheric condition permits interference with local stations by distant stations on the same frequency.  The fuzzy signal generally will clear up by noon.

Patrick Roberts / KGOU

Editor’s Note: This article was originally written by former KGOU Chief Engineer David White (1983-2006) and updated in 2013 by Chief Engineer Patrick Roberts (2007-present), and Operations Director Brian Hardzinski.

I'm sure many of you have experienced difficulties in picking up the KGOU broadcast signal at one time or another. Of course, obvious equipment failure in the broadcast transmission chain for KGOU's equipment could create listening difficulties.

However, there are more subtle things that can create occasional reception problems for the listener. FM broadcasting is normally a line-of-sight operation. Unfortunately, there are events in the world of atmospheric physics that can temporarily change this, making the signal nearly or totally un-listenable. In these cases, it is not your radio or KGOU's equipment.