====== Radio Receiver BC-224 ======
Developed by [[RCA]], manufactured for the U.S. Signal Corps by various manufacturers.

The aircraft receiver developed by [[RCA]] (Radio Corporation of America) was manufactured with various frequency coverages and operating voltages and was the predecessor of the well-known [[BC-348]] receiver used in long-range bombers.

===== Technical data =====
  * [[Principle]]: [[single conversion superhet]], [[IF]] kHz
  * [[Operation modes]]: [[A1]] with BFO, [[A3|AM (A3)]]
  * [[Frequency range]]: (200 kHz - 500 kHz), 1.5 - 18 MHz
  * [[Frequency display]]: [[analogue dial]]
  * [[Frequency memory]]: none
  * [[Signal strength indicator]]: none
  * [[Signal processing]]: 
  * [[Features]]: 
  * [[Sensitivity]]: [[A3|AM (A3)]] / [[Selectivity]]: kHz (-6/-60 dB)

==== Power supply ====
  * [[Batteries]]: 14 V DC from the aircraft electrical system, DM-24 dynamotor for conditioning the operating voltages.

==== Dimensions ====
  * mm, weight kg

==== Accessories ====

----

===== Operation =====

===== Variants =====
{{tablelayout?colwidth="80px,-,110px,-,-,150px"}}
^Type^Manufacturer^Voltage^Quartz - Filter^Comments^
|BC-224-A|RCA, 1936|14V DC|X|Dynamotor BD-94-A|
|BC-224-B|RCA, 1938|14V DC|X|Dynamotor DM-24-B, without long waves; 1500 - 3000 / 3000 - 5000 / 5000 - 7500 / 7500 - 10500 / 10500 - 14000 / 14000 - 18000 kHz|
|BC-224-C|RCA Contract|14V DC|X|Dynamotor DM-24-B, without long waves; frequency ranges see B version|
|BC-224-D|RCA Contract|14V DC|X|Dynamotor DM-24-B, without long waves; frequency ranges see B version|
|BC-224-E|RCA, 1940|14V DC|X|Dynamotor DM-24; 200 - 500 / 1500 - 3500 / 3500 - 6000 / 6000 - 9500 / 9500 - 13500 / 13500 - 18000 kHz|
|BC-224-F|Belmont Radio Corp.|14V DC|X|Dynamotor DM-24; 200 - 500 / 1500 - 3500 / 3500 - 6000 / 6000 - 9500 / 9500 - 13500 / 13500 - 18000 kHz; end tube 6K6|
|BC-224-G|RCA Contract|14V DC|X|Dynamotor DM-24; frequency ranges see E-Version|
|BC-224-H|RCA Contract|14V DC|X|Dynamotor DM-24; frequency ranges see E-Version|
|BC-224-K|Belmont Radio Corp.|14V DC|X|Dynamotor DM-24; frequency ranges see F-Version|
|BC-224-L|Belmont Radio Corp.|14V DC|X|Dynamotor DM-24, BC-224-C retrofitted with additional long wave range by Belmont; frequency ranges 200 - 500 / 1500 - 3500 / 3500 - 6000 / 6000 - 9500 / 9500 - 13500 / 13500 - 18000 kHz|

===== Technical principle =====
[[single conversion superhet]]

==== Components ====
The set is equipped with tubes: VT-69 VT-69 VT-69 VT-70 VT-69 VT-76 VT-68 VT-48

===== Technical documentation =====

==== Development ====
In 1936, the Radio Corporation of America (RCA) developed the BC-224-A, an aircraft receiver that covered the shortwave range in six bands and was powered by an on-board voltage of 14V.

In 1936/7, a slightly revised version with a DM-24 dynamotor power supply was launched; the sets covering the shortwave range bore the suffixes BC-224-B, BC-224-C and BC-224-D. Shortly afterwards, RCA developed the 28V DC version of the receiver, which was adapted to the higher on-board voltages of the new bombers; the receiver was the successful [[BC-348]].

Now came the desire for coverage of the long-wave band (200 - 500 kHz), which is used in the USA for the long-wave beacons used in aeronautical radio. The shortwave range 1.5 - 18 MHz was now divided into five bands, and the receiver was given the designation BC-224-E. In the BC-224-F (and -K) receivers, a [[de:6K6]] was used as the AF end tube.

{{gallery>:images?mil-usa-bc224*.jpg&0&80x80&lightbox&showtitle&titlesort}}
==== Further information ====
  * [[https://www.radiomuseum.org/r/military_radio_receiver_bc_224.html|Radio Receiver BC-224 on the website of www.radiomuseum.org]]