EMWIN Products

 

Our EMWIN Product Line

Tigertronics manufactures a full line of products for support of the Emergency Managers Weather Information Network (EMWIN). Our EMWIN product line includes demodulators and modulators for both direct satellite downlink operation at 1600 MHz and for use in retransmission applications. We also manufacture the ESP-96 EMWIN Signal Processor which is used on EMWIN "earth stations" for direct satellite reception.

All Tigertronics products are designed and manufactured to rigid specifications in our state of the art facility in Southern Oregon. We employ only the highest quality commercial grade components and do all assembly on our own highly automated assembly line. All products utilize surface mount technology and robotic assembly to insure superior quality, performance, and reliability.


What is EMWIN?

EMWIN is a broadcast system designed to distribute weather information across the entire United States. EMWIN broadcasts are transmitted 24 hours a day by the GOES 8 and GOES 9 satellites. These broadcasts consist of current state, national and worldwide weather information, weather graphics and satellite images. Warnings and watches for the entire U.S. are also broadcast and are normally received within seconds of being issued.

Currently, both GOES 8 and GOES 9 transmit 9600 baud EMWIN data at a frequency of 1690.6 MHz.  The newer 9600 baud signal is considerably more complex, employing DFSK modulation and v.35 formatting. The Tigertronics NWX-96 is required to demodulate this new high speed data stream.

In many areas of the country, it is possible to receive EMWIN broadcasts from "retransmission stations". These are stations which receive the signal directly from the satellite and then retransmit them on various VHF and UHF frequencies, either as a primary signal or as a subcarrier. Reception from a retransmission stations is considerably more economical, since none of the expensive earth station equipment is required.


What do I need to receive the EMWIN data?

To receive the EMWIN broadcasts directly from the satellite, you need an "earth station" (consisting of a satellite dish, low noise amplifier and a microwave receiver), an ESP-96 Signal Processor and a demodulator (either the ESP-96's optional built-in demodulator, or an external demodulator can be used). To display the data, you will need a Windows-based computer running RealEmwin or other EMWIN processing software.


What about receiving retransmitted EMWIN data?

To receive the EMWIN data from a retransmission station, you will need only a receiver, demodulator and computer system. With retransmission, your receiver or scanner is simply tuned to a local VHF or UHF radio station, so none of the earth station equipment is required. Retransmission stations normally transmit at either 1200 or 2400 baud and can be received on a scanner or receiver using our NWX-12 or NWX-24 demodulator. Note that as this page is being written (July 1998), there are currently two sites testing EMWIN retransmission at 9600 baud.


Further information on the EMWIN broadcast system is available from the EMWIN Home Page of the National Weather Service.


What EMWIN Products Are Currently Available?

ESP-96

The ESP-96 replaces the "modified scanners" that are customarily used with earth stations for direct satellite reception of high speed EMWIN broadcasts. See the ESP-96 Page for more detailed information.


NWX-12

The NWX-12 is for reception of the current EMWIN data format at 1200 baud (Bell 202 FSK). This is also the most common retransmission format. The demodulator can be attached directly to the audio output jack of a standard receiver or scanner.


NWT-12

The NWT-12 is the modulator that is required for retransmission of EMWIN signals.  The modulator attaches between the computers serial port and the modulation input of the transmitter. Data received by the modulator is converted to the appropriate FSK format required for transmission.


NWX-24

The NWX-24 is used primarily for reception of retransmitted EMWIN broadcasts at 2400 baud. The NWX-24 decodes MSK modulation and requires direct connection to the discriminator output of the receiver. Receivers that do not have discriminator output available, will require a simple modification to attach the demodulator. Note that the NWX-24 will not function properly if attached to the audio output jack of the receiver.


NWT-24

The NWT-24 is the modulator that is required for retransmission of EMWIN signals. The modulator attaches between the computers serial port and the modulation input of the transmitter. Data received by the modulator is processed and then converted to the appropriate MSK format required for transmission.


NWX-96

The NWX-96 is designed to receive the next generation of EMWIN broadcasts at 9600 baud. This demodulator is designed primarily for earth station applications, but may be used for high speed retransmission as well. The NWX-96 utilizes v.35 DFSK technology and requires a direct connection to the discriminator output of the receiver. The NWX-96 incorporates sophisticated digital signal processing for fully automatic synchronization and decoding.
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