The information in this video has been blatantly plagiarised from the following sites. Please visit the links below for detailed information about the HRO receiver and its important place in history.

Manual Here: https://www.dropbox.com/sh/a06hlbog65...

https://www.cryptomuseum.com/df/hro/

https://www.radiomuseum.co.uk/hro.html

https://www.electronicsnotes.com/art...

The National HRO was a valvebased (tube) shortwave general coverage communications receiver, manufactured by the National Radio Company (National) in Malden (Massachusetts, USA) from 1935 onwards. The receiver was intended for military and amateur use and became very popular for intercept work during WWII. Different versions of the radio were in production until the 1960s.

There are many versions of the HRO receiver and each new production run saw a number of smaller or larger modifications being made to the design. The most wellknown versions are arguably the latewar HRO5 and the prewar variant the HROM, both of which played an important role during WWII and both of which are still being used by Radio Amateurs today.