Weather Satellite Antenna description
The Weather Satellite Antenna, model UC-1374-531 is a +4 dBic Quadrifilar Helix (16 cm/6" OD x 62 cm/24.5" H) designed to operate in the APT Weather Satellite Band of 137 MHz to 138 MHz (137-138 MHz). It may be used to receive NOAA (US) and METEOR (Russian Federation), Weather Satellite data feeds, using narrowband FM receivers, such as those used by Radio Amateurs and VHF Enthusiasts. Weather maps can be received directly from a number of polar orbiting satellites with such receivers. Alternatively, dedicated, low cost Weather Satellite receivers are available to build your own Weather Satellite receive station (WX Satellite). A beginners guide to Automatic Picture Transmission Weather Satellite Reception can be found at APT Weather Satellite Reception (you may have to delete the "s" from the URL's https://... for the site to work). For details on the Weather Satellites, visit the NOAA/NESDIS pages for Polar Operational Environmental Satellite (POES), or the Meteor Satellites
Receiving WXSAT Images
Watch and listen to NOAA-18 APT weather satellite image being received at antennas.us on June 27, 2019 (click link below):
Video of NOAA-18 APT weather satellite image being received at antennas.us using an UC-1374-531R antenna and 50 ft of LMR-240 coaxial cable, without an LNA, and an RTL-SDR USB dongle receiver.
The received image is shown in black and white as it is received/recorded. Upon completion of the satellite pass, the image is processed to produce various views. The complete image received and processed can be viewed here, it is also the last photo above.
The satellite image is constructed by assembling narrow horizontal left to right camera sweeps. The uniform travel of the satellite, for example South to North, is responsible for the vertical sweep (bottom to top of screen). This is similar to how a computer printer renders a photo, or a scanner captures a document.
In some of the still images above, you will notice narrow horizontal bands of noise (black or missing dots/lines). They are often due to multipath interference from the ground at their corresponding elevation angles. Obstructions, such as buildings and heavy foliage can produce broader noise bands. In general, significant dips in signal strength produce noisy horizontal bands [similar to when an inkjet printer is almost out of ink, you get horizontal streaks of unprinted color]. On our June 27 image, the noise to the North is due to our building, as the antenna was placed on our parking lot, approximately 20 ft (7 meters) South of our building. The noise South is due to the horizon limit and more distant buildings.
to receive Weather Satellite images, you will need an antenna (like the UC-1374-531R), a sensitive VHF receiver capable of FM signals from 137.0 to 138.0 MHz with an audio output (earphone jack), WXSAT software (freeware available) and a computer. Links above have pointers to sources of WXSAT/APT receivers for purchase.
Weather Satellite Kit (WXSAT-APT-KIT)
To make the reception of satellite weather images more accessible, and in response to requests received, we offer a kit with all the components needed to receive Weather Satellite images on Windows desktop computers (Apple users: we are looking into including MacBooks too). The kit includes: UC-1374-531R antenna, LNAU-0137-648 low noise amplifier with built-in filter, 50 ft Coaxial Cable with connectors, USB Receiver dongle, software download and instructions. To go to the Kit's page, click --> WXSAT-APT-KIT page
- Frequency range: 137-138 MHz (VHF WXSAT Band)
- Coverage: Omni-directional, Hemispherical
- Polarization: Circular (Axial Ratio 1 dB)
- Peak Gain: +4 dBic (free space) [up to +6 dBic if properly mounted over a ground plane/ground]
Elevation pattern (free space - NO Ground Plane)
- Nominal Impedance: 50 ohm (RF) / Short Circuit (DC)
- Input Power: Receive only service (<5 Watt CW)
- VSWR: 2.0 VSWR chart
- Connector: Type N, Female on side
- Housing 16 cm (6") OD x 62 cm (24.5") h
- Bottom flange 19 cm (7.5") OD x 12 mm (0.5") h
- Mounting: 8 screws, M6 (#1/4-20)
- Operating Temperatures: -40C to +85C
- Weight: 3.1 kg (6.8 lbs)
UC-1374-531 QFHA Drawing
- Does not require a ground plane