Change in seasons
As the seasons change it is time to consider seasonal checks and fixes at the transmitter site. The hazards of wildlife (plant and animal varieties) will subside with the cooler weather. Just as in spring, it is a good idea to spray around doors and windows with some wasp spray to deter these pests from hibernating in the transmitter building. And since field mice and other vermin will also seek refuge from the cold, any cracks or crevices should be sealed to keep them out. As an extra measure, traps can be set to catch anything that does find its way in, which will prevent trouble later on in the form of gnawed wires and other vermin damage.
The transmitter ventilation system should be inspected and all motors and dampers lubricated, drive belts replaced and controls checked for proper operation. The intake and outlet temperatures of the transmitter air should be measured and noted for reference. Any filters in the system should be cleaned or changed — bear in mind that foam filters decay and fall apart. Consider swapping these types of filters with either pleated paper or fiberglass types; these are often more readily available at hardware stores and home centers, and are cheaper than foam types.
Run a security check: all gates, doors and other points of entry should be locked with working locks. Large sliding gates should be greased. Padlocks can be weather-proofed by soaking them with WD-40. This often prevents them from freezing in the winter. Another old trick is to make a cover for the lock out of a piece of a rubber inner tube. Be sure all perimeter lighting is working properly, and if they operate on a timer, reset the turn-on time as the darkness falls earlier.
If the transmitter building has supplementary heat, make sure there is fuel in the tank for it. If there is a back-up generator it is time to make sure it, too is winterized and has fuel.
Some cool tools
Extech Mini IR thermometer (Extech 42500): This gun-type thermometer will read the surface temperature of an object without touching it. It is handy for finding hot spots inside a transmitter or for finding bad components on a circuit board.
The Extech Mini IR thermometer.
Steel letters and numbers (McMaster-Carr 8600T42): How many keys do you have? How do you tell them apart? Labels wear off. Paint sometimes works, but you need 80 different colors. Manual etching is really tough on something so small. These steel numbers and letters ⅛" high will allow easy identification of any keys. Just hold the die and tap it with a hammer. For security reasons, I never use call letters on the keys, but the last 4 digits of the site phone number. And there is a jig that will hold the die still (McMaster-Carr 86805777) so the finished work will look better.
Paladin Tools long reach BNC extractor (Paladin Tools 1907): Anytime you have a rack-mounted piece of equipment, there is usually a BNC or F connector on it you can't grab with your hand. This long-handled tool will slide around the connector and hook on. A slight twist will get it unhooked.
A backup generator should be installed with an automatic changeover switch and power loss sensing relays. However, many installations may only have a generator. Or in a few cases, a portable home type generator can be used to keep a backup transmitter of up to 1kW on. Remember there is no excuse (even in an emergency) to disregard safety practices. The loose wiring of even a small generator to a power panel is not only unsafe but dangerous. If not done properly, the generator can be destroyed when the regular power comes back on. If you are in one of these situations, there is a safe and quick way to install a manual changeover.
Industrial disconnect switches are available from Square-D and other electrical manufacturers in sizes that can handle up to 100 amps. Many are in enclosures. Simply wire the wiper of this switch to the main circuit breaker panel (totaling not more than the capacity of the switch), and one side to the regular power and the other to the generator. A status indicator for the regular power should be installed. It can be as simple as a relay plugged into an outlet, or if the site will be staffed during the outage, it can be an incandescent bulb (compact fluorescent bulbs should not be used since if the power comes back under voltage they may not light).
Landry is an audio maintenance engineer at CBS Radio/Westwood One, New York.
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