[Milsurplus] C-405A/A vs. C-740/ART-13

[wf2u at starband.net]

The Russians did a smart thing with their BC-348 copy, the US-9.
They manufactured a modified US-9, model US-9DM which didn't have local
controls. The front panel had servos installed where the band selector
switch is, and another servo was where the tuning knob was, and no local
dial was installed. The gain control and function switch was remoted. The
power supply was an external 115VAC @ 400Hz primary supply, because the
internal space where the dynamotor was was taken up by some remoting
circuitry. There was a big Canon-type power/remote connector on the bottom
left side of the panel instead of the original rear power connector. The
receiver was completely controlled and tuned from a remote control panel
in the cockpit (on aircraft with no radio operator), and a remote control
similar to that of the ART-13 for the R-807 transmitter (the Russian
ART-13 copy) was used, thereby the receiver was tunable and the
transmitter had the 10 preset channels. The Russians didn't have a 10
channel preset tunable receiver like the ARR-15. Later they made another,
remotely controlled receiver - the US-8 -  which doesn't resemble the
US-9DM except in size and shape factor, but inside it's a different,
modern design and all miniature tubes, equivalent to the 6BA6, etc. -
common 6 V tubes equivalent to US tubes.

I have photos of all these models.

73, Meir WF2U
Landrum, SC
> Hi, Folks,
>
> On 9/19/07, Mike Morrow <kk5f at earthlink.net> wrote:
>
>> Using the C-131 and R-26 with the T-47 is (IMHO) a typical USN
>> kludge-job arising from the USN not having a receiver matching the
>> characteristics of the T- 47/ART-13 until the AN/ARR-15 arrived (but
>> even that receiver provided no LF/MF beacon band coverage).
>
> Not quite so.  The Navy used the ATC - T-47/ART-13 with the ARB in a
> typical installation which, while it didn't have the full coverage the
> transmitter did, was adequate to their purposes.  Further, the ARB was
> cockpit tuneable which the BC-348 wasn't.  What the C-131-equipped R-26
> did offer was the ability to autotune the receiver with the
> transmitter, a function that was expanded with similarly equipped
> R-27s.
>
> These two systems went into TBMs and SB2Cs for certain and possibly into
> other aircraft.
>
>> The USAAF AN/ARC-8 used the AN/ARR-11 (BC-348), which very well
>> matched the associated T-47A/ART-13,
>
> So did the Navy later on from acquiring USAAF aircraft.  Rather than
> swap out the receivers, they kept using them with a few modifications
> like an SO-239 in place of the antenna post.  These were used
> concurrent with the ARR-15(A).
>
>> except for lack of receiver remote control capability.
>
> The Navy found that a valuable attribute, especially in smaller
> aircraft like the TBM & SB2C.  In the meantime, the larger aircraft were
> flying with GO & GP transmitters with RU receivers (among
> others.)  This, in turn, makes me wonder if the RU was ever paired with
> the ATC.
>
>> The USAAF/USAF and the USN marched to slightly different drum beats in
>> the same time interval.
>
> They still do!
>
> Best regards,
>
> Michael, WH7HG
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