Part 1: National HRO 50 Shortwave Communications Receiver, Complete Rebuild!

The National HRO-50 shortwave receiver utilizes plug-in band coils. Supplied coil ranges: A 14-30, B 7-14.4, C 3.5-7.3, D 1.7-4 MHz. Other optional coils: E 900-2050, F 480-960, G 180-430, H 100-200 and J 50-100 kHz. Also: AA 27.5-30, AB 25-35, AC 21-21.5 MHz.
A micrometer type dial drives the main tuning capacitor through a worm drive having a reduction ratio of approximately 20 to 1. The dial has an effective scale length of approximately 12 feet and is calibrated 0 to 500. Features include: ź" Headphone Jack, S-Meter, Antenna Trimmer, Hinged Top Cover, RF Gain, Dial Lamp, Dimmer, Phono Input Jack, Tone, BFO, Bandspread on most standard ranges plus AVC ON/OFF. Output is 8 or 500 ohms. Shown with 50TS speaker (sold separately).