The station’s Facebook page showed video of the fire with the caption, “Our transmitter caught fire today. THIS IS NOT A STUNT. An investigation is underway. Any ideas on the culprit?”
Cumulus owns the station and it remained on the air, broadcasting to 95% of its coverage area, when the backup transmitter kicked in. Cumulus Market Manager Sean Shannon told The Atlanta Journal-Constitution it’ll take some time to get the transmitter repaired, which is located on top of the Weston Peachtree Plaza Hotel.
Shannon told the paper there was no sign of lightning in the area.
The “culprit” is likely a loss of pressure in the feedline and antenna, assuming that that system is pressurized with either nitrogen or dry air. Water then condensed at the bottom bay of the antenna and an RF arc resulted, igniting the radome over the bottom bay. If the transmitter is operated into a dummy load, it will probably work fine.
Sensationalism at its worst…
Looks to me like the transmitter didn’t catch fire at all. But the bottom bay of the antenna…or at least its radome did. No culprit, unless someone had the b-lls to climb the mast and do something to that bay. Probably the pressure dropped (if that system is pressurized with nitrogen or dry air) and water condensed in the bottom bay, causing an RF arc. The transmitter itself is probably fine…check it into a dummy load.
Sensationalism at its worst!
My fear is this: when we make announcements such as this and without serious consideration of the language used, it can inspire knuckle-heads to copy cat activities.
Well, if the transmission line and antenna were at the end of a chimney attached to the transmitter vent system down in the TX room, I suppose you might think a transmitter fire could provide smoke up the mast. (Not really!) Kirk is obviously spot on with his assessment. This is a perfect example of the poor use of terminology or maybe the lack of understanding of lay folks about how technology works. I think Kirk and I would have been satisfied if the story described it as a transmission system failure and fire even though the photo specifically shows smoke emitting from the lowest bay of the FM antenna.
Well, that’s not a transmitter on fire; it’s the bottom bay of a 4-bay antenna.
Shane Toven had a salient comment on their Facebook page…
“ Unless someone shot at the antenna with a high power rifle to start this fault, I highly doubt this was intentional. No “culprit” or vandalism here to be found more than likely. The “investigation” will involve a tower crew disassembling the antenna to find where the fault occurred, and likely replacing both the antenna and transmission line.
This can happen in high power antenna systems for any number of reasons. It looks like that particular antenna bay suffered a fault, and the transmitter(s) did not shut down before the heat and electrical arcs caught the antenna’s fiberglass radome on fire. Normally there is protection in place to prevent damage from getting this severe, but sometimes that protection can fail to detect certain issues. I have seen cases where an antenna bay was literally dangling from the tower but the transmitter still thought everything was perfectly fine and continued operating at full power.”