The Experimenters Antenna Amplifier is ideal for Field Day, portable or temporary receiver installations where temporary antennas have to be rigged to take advantage of the space available. The RF overload protection allows it to be used very close to transmit antennas. It is also ideal for fixed installations.

It contains all the electronics needed for home DIY construction of a range of active antennas including small loops, Beverage, Flag and e-field probe types.

The amplifier consists of two units, a weatherproofed outdoor head unit for connection to a suitable loop and a bias tee unit to provide DC power up the coaxial cable to the outdoor unit.

The outdoor unit is housed in a polycarbonate box with stainless steel antenna connections and a BNC socket. The bias tee unit is a PCB with two BNC connectors and a DC socket to take DC power from a battery or power supply with centre pin positive.

Like our other active antenna products it has RF overload protection to allow it to be used very close to transmit antennas without damaging the amplifier or the attached receiver.

The amplifier uses a tapped isolation transformer so that a range of antenna impedances can be used. We supply a 2.5 m (8 ft) length of wire as a simple loop to make a first loop for testing.

To isolate the antenna element from the receiver the amplifier has two isolation transformers in the input and a common mode choke on the 50 ohm output.

Specifications:

Frequency range (Experimenter's Antenna Amplifier):  500 kHz to 55 MHz

Input impedance: Loop 50 ohms, Beverage 450 ohms, Flag 900 ohms

Output impedance: 50 ohms

OIP2: >+70 dBm

OIP3: >+32.5 dBm

Gain (head and base units Experimenters Antenna Amplifier): 25 dB at 14 MHz

Noise figure: 0.79 dB

Supply voltage (head unit): 9 to 15V from a bias-tee feed via the coaxial cable

Supply current (head unit fed with 13.8 V from bias-tee): 27 mA

Experimenter's antenna outdoor unit connectors: Four M6 stainless steel threaded studs (Common, Loop, Beverage and Flag) and BNC female (RF out 50 ohms)

Experimenter's antenna amplifier bias tee board connections: BNC female (RF input and DC feed to outdoor unit), BNC female (RF output to receiver), DC connector (for 9 to 15 V DC power input) centre pin positive