HRO and its German Replicas
HRO-5T - National Company communications
receiver. Covers 0.05...30.0 MHz in 9 sub-bands, A1 / A3.
Band switching by manual change of plug-in coil sets.
be continued after the picture set...
HRO receivers had very special appearance due to the very unusual micrometer
dial combined with tuning knob. The micrometer dial had five windows where
numbers from 0 to 500 were visible. Those numbers were changing in steps of 10
when tuning knob was rotated by the radio operator.
operator had to convert the reading on the knob into frequency by looking at a
curve on the front of the coil set, yet this only gave a general indication of
frequency. HRO military versions shipped to the UK came with individual
calibration booklets giving the dial reading for each kilohertz.
National HRO receivers were supplied to the USSR by the Lend-Lease Act in
1942-1944, primarily HRO-5T with metal tubes.
National HRO was also one of the most copied receivers of WW II. There were
German, Japanese, British, Australian and Swiss copies known. Some of HRO replicas are on display in