HRO Var. 3 (according to Moore)

• alternative name: National Toy Co.
• Brand: Thrillbox

Coverage :

1.7 – 30 MHz ( 4 standard ganged coil sets for 1.7 – 4, 3.5 – 7.3, 7 – 14.4, 14 – 30 MHz included, 2 coil sets for broadcast immediately available at extra cost, 7 more coil sets sold later including long waves ( total spectrum covered from 50 kHz to 54 MHz ).

Modes AM / CW/SSB (BFO).

The 0 – 500 epicyclic readout dial allows for continuous analog tuning while digitally indicating incremental progress over a range of ten full turns of the large tuning knob that tunes with velvet smoothness. Ten times the circumference of the dial is nearly 4 meters on a normal dial scale, which delivers great frequency resolution. The dial is not calibrated to directly indicate a frequency but a frequency calibration chart is necessary to determine the correct operation frequency.

Bar knobs with metal skirts, S-meter toggle switch, pilot light left of selectivity control, engraved panel markings for B+, AVC and Selecctivity, metal look dial knob, black colourted chassis and round IF transformers.

External power supply : PSU 697 or standard 5886 ("dog house" type).

In questo link sono elencati 445 modelli, di cui 284 con immagini e 189 con schemi.
Elenco delle radio e altri apparecchi della National Company; Cambridge & Malden (MA)