Active Ferrite Rod Antenna OH2NLT


Matti OH7SV did some tests to find out if Active Ferrite Rod antenna can be build for 80 / 40 Meter ham band reception. Matti’s experiments are documented here.


I did boxed version of this antenna for practical tests. Antenna construction presented with few pictures.

Slightly modified OH7SV schematics

Mechanics 80x110mm plastic box

General construction

Amplifier with SMD components but without PCB

Boxed antenna

During weekend we did some field tests with this antenna and JUMA-RX1 HF receiver. Results where better what we expected. In interference free place this little antenna picks signals as good as poor wire antenna. Antenna is direction sensitive. This characteristic can be used to minimize or even zero interference signals if they come from one direction.


I found old TV set deflection circuit compensation coil. Coil was wounded with 28x0,15mm Litz wire. This is perfect stuff for low loss ferrite antenna primary winding.

Litz wire test coil