Almost countless radio receivers have been designed, but some have become more famous or represent major improvements in radio receiver design performance.
On this page we will aim to list some that, in our opinion, have become a major milestone in receiver design, or they are of interest to many.
- National HRO: This receiver was a 9 tube / valve general coverage HF communications receiver manufactured by the National Radio Company of Malden, Massachusetts, United States.. The HRO was announced in October 1934 and the first units were shipped in March 1935. This meant it was ready for use at the outbreak of World War II. It was extensively used for monitoring, even being used in the UK by listening stations for Bletchley Park. The HRO had two very distinctive features: a micrometer type dial; and plug-in sets of tuning coils that slid into a full-width opening at the bottom of the front panel.
- Marconi CR100 : This radio receiver had an 11 valve / tube line-up and covered from 60Kc/s up to 30 Mc/s. The receiver was used by the UK and “Empire” forces. The CR100/2 was also called the R.A.F. type R1297 receiver, as it was issued to the Royal Air Force and the other services, except the Navy.
- 19 Set: This was a transmitter / receiver that was used by the forces of many countries in World War II. It had a straightforward line-up and was housed in a rugged case. It was used in everything from tanks to jeeps and for portable operation as well.
- RCA AR88: The RCA AR88 was one of the workhorse radio receivers used for surveillance during World War II. Designed by RCA in the USA it entered service in around early 1941. The AR88 was a 14 tube or valve superheterodyne radio that covered 0.54 to 32Mc/s in six bands. It offered good sensitivity, especially for the time up to 30Mc/s, good stability, and reliability when compared to other receivers of the day.
- Racal RA17: The Racal RA17 was developed by Racal based in Bracknell UK. It was revolutionary because it was a high performance communications receiver that included a system called the Wadley loop that eliminated the frequency drift that all previous receivers had experienced. As a result many thousands were produced, being used by a variety of monitoring services. . Read more about the Racal RA17 Receiver.
This includes a small selection of some radios that have been used down the years. Some could be bought commercially, whereas others became available on the military surplus markets and were bought by radio amateurs, and other enthusiasts.