[ARC5] Distribution of ARC-5 Audio

[Michael Hanz]

On 4/23/2016 7:33 PM, Cliff Miller wrote:
> In an aircraft with multiple receivers, how was the audio output 
> controlled and distributed?  Were the audio outputs bussed together or 
> switched somehow so an individual user would only hear one receiver?

There is a very large number of answers to your question - as posed.  
First you have to define what you mean by "aircraft" - size, number of 
crewmen, primary mission, etc.  Then you have to define "individual 
user" in terms of their role in the aircraft.  The audio distribution in 
a military aircraft (normally called the interphone system) followed 
various paths over the years, growing exponentially more complex by the 
end of WWII because of the specialization of aircraft missions into less 
well known groups like countermeasures and signals intelligence.  One 
place to start is at 
http://aafradio.org/flightdeck/Interphone_systems.html where you can see 
the trends from the earliest RL-** Navy and USAAC RC-** interphones to 
where it all was going by the last system on the page (the AN/AIC-5).  
You'll see two different control boxes associated with that set, with 
different degrees of receiver selection.

The AN/AIC-5 gradually evolved through the 1950s - for example, the 
AN/AIC-7 was essentially an AIC-5 with high intensity loudspeakers added 
for internal and external use.  Its manual states, "The pilot, copilot, 
radio operator, and navigator are each provided with a master control 
unit that permits selecting any one or combination of eight radio 
receiver outputs as desired."  The next generation appeared in the 
AN/AIC-10, which became perhaps one of the most prolific systems in the 
inventory.  It bridged the gap between tubes and transistors - I have 
one each of a couple of LS-184/AIC-10 loudspeakers with internal 
amplifiers that represent that shift from tubes to solid state.

73,
Mike  KC4TOS


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