Cross Country Wireless HF Active Antenna

Product discontinued, web page for information only. Look at our new Loop Antenna Amplifier...

The HF Active Antenna was developed as part of the development work for the Sentinel HF SDR noise measurement receiver and program.

There was a need for an antenna that could be used for accurate RF measurements over a wide range of HF frequencies without being affected by coupling to nearby metallic objects or RF noise from common mode coupling on the feeder and would give long term repeatable results.
If it was an active antenna it also had to be capable of surviving high RF field strengths from HF transmitters operating on the same site and be tolerant of mounting position and supply voltage.
It also had to be built from the highest quality materials to work unattended for years in all weather from arctic to tropical conditions.
It also had to be sensitive enough to receive and measure the RF noise floor at the quietest sites without being overloaded by the strongest broadcast signals in the HF bands.

Now that the RSGB noise measurement project has ended we have redesigned the amplifier used in the antenna to extend coverage down to 10 kHz. Early versions were limited to 200kHz.

This is the result...

Features include:

• Balanced small dipole design using two 0.65m stainless steel elements

• Frequency range 10 kHz to 50 MHz (version 2)

• Uses low cost ethernet cable to connect between antenna head and base coupling unit

• RF gain equivalent to an isotropic antenna (0 dBi) from 100 kHz to 50 MHz

  

• Transformer balanced coupling to ethernet cable for excellent common mode rejection

• RF overload protection allows use in close proximity to transmitting antennas without damage

• Outdoor unit has polycarbonate enclosure with brass and stainless steel fittings

• 20m of outdoor ethernet cable terminated with RJ-45 connectors included with each antenna

• DC supply requirements are 12V at 120 mA

The HF Active Antenna Operating Manual can be downloaded here .