Engineer's Corner
1:43 pm
Tue November 12, 2013

TheEC: 91.5 is Back On the Air

WCVY temporary transmitter
From top to bottom, Bext LEX30 transmitter, Dayton 210 FM receiver tuned to 102.7 to get programming to feed the transmitter, and Inovonics 631 FM receiver to monitor 91.5 on the speakers above.
Credit Aaron Read

As of Tuesday November 12th, WCVY is back on the air in limited fashion.   As you know, WCVY suffered catastrophic damage to its equipment and facility from a roof leak during a thunderstorm in August.   The entire space had to be gutted to the concrete walls, and new electrical wiring and drywall installed.  Much of the transmitter gear either took direct water damage (e.g. electricity shorting out) or took indirect water damage (e.g. rust and other corrosion), and eventually a lot of it failed completely.

We have put a temporary setup in place with a donated 30 watt transmitter on loan (with the antenna array's gain factor of 2.1, it's really more like 63 watts of Effective Radiated Power), and a special radio that's tuned to 102.7FM (there's a high-gain FM antenna on the rooftop tower) and puts out the composite signal directly into the new transmitter.   This effectively makes 91.5 into a "repeater" of 102.7FM.

63 watts is not the full 200 watts of power WCVY is normally authorized for.  But since wattage is a logarithmic equation (not a linear arithmatic equation), seemingly big changes can have small consequences.  For example, +3dB of signal is the equivalent of doubling the wattage number, so from 63 to 200 is maybe +4dB of change.  That's really small in terms of perceived signal received at your radio...less than halfway the distance between the red and purple contours in this signal map.  Your own body causes more than a 3dB change in signal just by walking in front of an antenna.

And of course, 63 watts is a lot better than zero watts!  :-)   This should suffice until the insurance claim gets processed and new transmitter, processor, mix board, EAS and other gear are purchased and installed.