[ARC5] which modules?

[Mike Hanz]

On 6/24/2014 9:48 AM, David Stinson wrote:
>
> ----- Original Message ----- From: "J Mcvey via ARC5" 
> <arc5 at mailman.qth.net>
> Subject: [ARC5] which modules?
>
>
>> which modules do you use?
>> I guess the c-29/ c-30 transmitter control are a given,
>> but what is the difference between them?
>
> C-30 was designed to operate the radio configuration
> that incorporated the AN/ARC-5 VHF pair within
> the existing and most common 2 TX - 3 RX deployment.

Dave gave a good rundown on the C-30's purpose, but just to confuse 
things further, there was the original C-30/ARC-5, and later a 
C-30A/ARC-5 that was issued to correct a number of problems with the 
first version.  BuAer Technical Note No. 93-44 announced availability of 
the C-30-A in the September 1945 issue of Airborne Radio Maintenance 
Notes, though the pub number suggests that it was in the pipeline for 
some months before the ARMN issue.  The most significant problem with 
the C-30 was loss of the phenolic pushbuttons and breaking of the shafts 
that the pushbuttons slid over.  The C-30 and C-30-A basically added a 
second layer of switching to the C-29 to permit control of four channels 
on the VHF transmitter and receiver when it was selected as one of the 
four possible transmitter alternatives on the other switch.  By the time 
the C-30 came out, the Services were beginning their transition to VHF 
for command functions, so it made sense to simply install a C-30, (or 
later, the C-30A) rather than installing a C-29 and then have to change 
it out.  You could still use the C-30/30A to control four transmitters, 
just like the C-29.

Your other question was about the C-39/C-48 interphone box, and I sure 
wouldn't consider it essential.  It was designed for multiple place 
aircraft, and allowed the choice of two different microphones, e.g., 
oxygen mask mike and hand held mike, as well as a local volume control.  
It functioned simply as an audio jack box.  It was designed to be daisy 
chained with others.  The standard interphone box was, as AB5S 
suggested, either the J-16/ARC-5 or J-22/ARC-5 - the latter coming in 
two versions.  The manual describes the somewhat arcane details of each, 
but any of them will do fine for a ham radio set.

73,
- Mike