Upon powering up the unit all 4 front panel LEDs will come on for 3 seconds with the alert LED flashing. After the unit completes the boot up, only the green power-on LED will remain lit.
- The Mute-Demute Button will toggle weather service audio on the internal speaker, as well as, to the 600 OHM balanced audio output terminals 3 and 4 on the rear terminal plugs.
- The Relay Reset Button will toggle the internal relay on and off. When the yellow LED is on, the relay is energized and supplies a dry contact closure across terminal 7 & 8 on the rear terminal plugs.
- The Replay Alert Button will turn on the amber colored LED and play up to 2 minutes of audio associated with the last alert received from the weather service that had a county that is programmed into the unit in the FSK header Code. The end of the stored audio will play the first burst of FSK in the 3 end of message FSK bursts. The stored audio can be muted at any time by pushing the replay alert button and the amber colored LED will go off.
- The Volume Control will regulate the amplitude of audio on the speaker for weather service audio, as well as, the level of the replayed stored audio.
- The EXTERNAL ANTENNA is connected to the Model CRW-S with an “F” connector on coaxial cable. At locations that are distant from the weather service transmitter low loss foam dielectric cable is recommended. It may also be necessary to use a high gain Yagi antenna.
- The BATTERY STANDBY terminals can be used to power the radio with 12 Volt DC power if commercial power fails (pay attention to polarity). Alternately the radio can be plugged into a U.P.S
- THE 15V 600 ma RECEPTACLE is used to power the unit up with the AC adaptor labeled CRW-S Weather Radio.
- The first 3 switches of the 8 position DIPSWITCH are used to tune the Model CRW-S to the local weather radio transmitter. The silk-screened table on the left of the rear enclosure lists the positions of the first 3 switches for each of the weather service transmit frequencies.
The 2 removable black plugs on the rear can be wired by inserting a stripped wire into each position and clamping the wire with a jeweler’s screwdriver. Folding the stripped wire back on itself before clamping will make a better connection when it is clamped.
10 Terminal Removable Black Plug
- Terminal 1/2: Balanced transformer coupled 600 ohm continuous weather service audio at 0 dbm is present on these terminals.
- Terminal 3/4: Balanced transformer coupled 600 ohm gated weather service audio is present on these terminals when an alert message is addressed to the location of the receiver. The audio is turned off with the first burst of EOM
- Terminal 5/6: A momentary contact closure can be wired into these 2 terminals to duplicate the function of the front panel relay reset function.
- Terminal 7/8: These 2 terminals supply a dry contact relay closure when the relay is energized The first burst of EOM will de-energize the relay and open the contact closure.
- Terminal 9/10: Not currently used.
8 Terminal Removable Black Plug
- Terminal 11/12: 8 ohm (speaker level) gated audio out that is present when an alert message is addressed to the location of the receiver. The first burst of EOM will shut off the 8 ohm audio.
- Terminal 13/14: If the radio is installed in a secure room the function of the front panel alert flashing LED can be duplicated at another location
- Terminal 15/16: A remote push button switch can duplicate the function of the front panel replay alert button.
- Terminal 17/18: A remote push button switch can duplicate the function of the front panel mute-demute button.
A computer can be used to program the counties in the area where the radio is installed through this P.C. port.
This can be used with a sign board to crawl the text of an emergency message at a remote location from the Model CRW-S.
The weather service signals an alert by sending a coded message in the following sequence:
- 3 BURSTS OF FSK Each burst of FSK contains coding that identifies that the message was originated by the weather service followed by a 3 letter code that selects which event out of the table of 49 approved event codes has made the message necessary. (i.e. tornado warning, child abduction emergency, evacuate immediately etc.) In addition a string of counties follows identifying which counties are affected by the alert. The list of counties can be anywhere from 1 county to 32 counties. This is followed by the date and time, as well as, how long the event is expected to last.
- 1050 CYCLE ATTENTION TONE After a 1 second pause the FSK is followed by a continuous 1050 cycle attention tone for 10 seconds.
- SPOKEN MESSAGE After a 1 second pause the attention tone is followed by a spoken message that cannot exceed 2 minutes in length
- 3 SHORT BURSTS OF FSK Each burst contains the end of message code
Operation of Receiver
The CRW-S will continuously operate in the muted condition but the mute-demute button can be used to listen to the routine weather update at anytime.
There are three operation modes of the CRW-S which depends on the counties programmed in the unit and the location of the unit.
- If the weather service issues an alert and the FSK coding does not contain a county that is programmed into the CRW-S the radio ignores the message.
- If the alert contains a county that is programmed into the CRW-S but does not contain the county in which the radio is located, the radio will demute and play 3 seconds of attention tone on the speaker and set off the flashing red LED. The audio portion of the message will then be heard on the speaker and simultaneously be recorded in the digital storage unit (spoken message cannot exceed 2 minutes). The arrival of the first of the 3 bursts of EOM (end of message) FSK code will mute the radio and shut off the digital storage unit. However, the red alert LED will continue to flash. If the room where the radio is installed was unattended or if personal were distracted, they can press the replay alert button and hear the complete spoken message to judge its urgency. When replaying the spoken message the first burst of EOM (end of message) will be heard at the end of the stored audio. Replaying the alert audio will also extinguish the flashing red LED.
- If the incoming message FSK coding includes the county in which the radio is located. In addition to the above sequence of events a relay contact closure will occur. If the event is life threatening (tornado warning, sever thunderstorm warning etc.) this contact closure can be used to turn on an intercom system or set off a remote signal at another location.