Beschreibung
What it does
A helix tuned to 1700 MHz, available in two versions. The 10-turn is the direct version: mounted on an el/az rotor without a dish, it decodes HRPT (High Resolution Picture Transmission) downlinks from NOAA POES and MetOp weather satellites in LEO. The 3-turn is the dish-feed version: its broader pattern is dimensioned to illuminate a reflector, which is what you want for the 1691 MHz downlink of the Russian Elektro-L geostationary weather satellites.
Choosing the polarization for dish use: a reflector reverses the sense of a circularly polarized signal. The weather satellites transmit RHCP, so a feed sitting at the focus of a dish has to be LHCP. That is why the 3-turn defaults to LHCP and the 10-turn, which looks at the satellite directly, defaults to RHCP. Pick the sense to match your setup, not the satellite.
Specifications
| Parameter | 3-turn (dish feed) | 10-turn (direct) |
|---|---|---|
| Center frequency | 1700 MHz (1690–1710 MHz) | 1700 MHz (1690–1710 MHz) |
| Polarization (default) | LHCP | RHCP |
| Helix turns | 3 | 10 |
| Wire diameter | 3.5 mm | 3.5 mm |
| Connector | N-type (female) | N-type (female) |
| Mount | 40 mm LNB clamp via Electronics Cover (sold separately) | 6 × M4 bolts (universal) for el/az rotor |
| Material | PETG, UV-resistant | PETG, UV-resistant |
| Color | Orange/White (default), Custom on request | Orange/White (default), Custom on request |
Live reception demo
Our Lab WebSDR streams live L-band downlinks from the station (currently offline for maintenance).
Typical use cases
- NOAA-15/18/19 and MetOp-A/B/C HRPT decoding (with rotor tracking)
- Russian Elektro-L geostationary weather imagery (with an offset dish, where the satellite is at usable elevation)
- Spectrum monitoring 1690–1710 MHz
Compatible chain
Identical to the Inmarsat 10-turn — see L-Band Inmarsat 1525 MHz for LNA / SDR / mounting details.
Color options
The Color option applies to the 3D-printed parts only — the baseplate and rim. The radome pipe is always white, regardless of the Color choice.
- Orange/White — orange baseplate and rim with the standard white radome pipe.
- Custom — custom color for the baseplate and rim. White is a valid choice; pick Custom if you want a uniform white antenna.
Documented in the Lab
- Lab overview — WebSDR feeds + station details
- L-Band Antenna Updates
Custom polarization or color combinations available on request — please use the contact form for a quote.
