Combining the best design features in terms of sensitivity, receive signal spread and noise figures to provide the best possible reception of as many satellites as possible to provide an accurate and reliable 3D fix. The aerial is fitted with 10 metres of RG58 cable terminated to a BNC male connector. The Onwa KA-09 GPS aerial has a BNC push and twist fitting - the most widely used fitting for GPS equipment. Some manufactures have moved to an SMA fitting and Feruno have generally used a TNC type (similar to BNC but with a screw fitting). Which ever type you need we have the appropriate adaptor to convert the BNC that is fitted as standard to suite your other equipment. Choose from the list of variations if you need an adaptor.
Why you should buy the Onwa KA-09 GPS aerial over another GPS aerial offered on eBay:
- Genuine Onwa branded product supplied by official Onwa UK Distributor
- Latest design, can be flat mounted on a horizontal surface providing a space saving and aesthetic presentation
- Designed with an optimum gain of 27dB for strong signals combined with great signal spread*
- 24 month UK warranty
- IP67 waterproof
- Very high performance
- Standard 1" 14 thread mounting
- 10 metres RG58 cable terminated to BNC with choice of adaptors if needed
- Sent by Royal Mail Tracked 48
* An explanation regarding aerial gain figures and why a compromise is needed between directional sensitivity and signal coverage.
The satellites sending GPS information are around 12500 miles from the earth's surface so good sensitivity is vital requiring a high gain aerial. Active GPS aerials contain an amplifier to boost the quite weak signals but the amplifier also amplifies noise so the original signal must be first class before being amplifed. A very high gain aerial should meet this requirement. On the other hand, the satellites are spaced across the sky from East to West so an aerial is needed that is not directional and that type of aerial is low gain. You can see that a very high gain aerial is good for reception but less good for receiving over the 180 degrees needed to receive many satellites. The Onwa GPS aerials are +27 dB which is an ideal compromise of sensitivity gain and satellite spread. At least four satellites are needed for an accurate 3D GPS fix so the aerial must have a reasonable signal spread to accomodate this. We are situated in Scotland and receive strong satellites via a KA-09 aerial (without any further amplification) and as a result the Onwa aerial provides a very excellent fix. Some GPS aerials may use a much higher gain aerial, possibly providing a stronger signal, but it will be at the expense of signal coverage from satellites. This is an often argued subject, even amongst some who sell aerials yet don't understand that aerial gain is not the same as gain from turning the volume up on an amplifier. Yes, more aerial gain does get more signal capture but at the expense of signal spread. The VHF aerial on your boat is an excellent example, a gain of 1dB to 3dB (very low gain) is considered excellent for a VHF aerial as reception from 360 degrees is necessary. An aerial with a gain of 30dB (high gain), would be quite useless unless it is pointing at or nearly at the transmitter.