[ARC5] Radio Equipment installed in Grumman F6F-3 at NMNA

[Mike Morrow]

John/W4THQ wrote:

>The following were removed from the aircraft:
>
>A 3 receiver rack/mount was present containing three receivers: an ATA receiver 0.19 -
>0.55 MC;  an R-27/ARC-5 6 - 9.1 MC ; and an ATA receiver 0.52 - 1.5 MC.  Also, a
>receiver control box for 3 receivers, ATA CBY- 23251 was included.  Two receiver
>nameplates were not readable as to Type.

Those are ARA receivers.  ATA is the associated transmitter system.

The .19 to .55 MC set is a CBY-46129.  The .52 to 1.5 MC set is the CBY-46145.
The 6 to 9.1 set should be a CBY-46106, but in practical service use the later
R-27/ARC-5 unit that you found would have been interchangable.

>A 2 transmitter rack/mount ATA CBY- 52212 was present containing: two transmitters:
>ATA Type CBY- 52210, 5.3 - 7.0 MC; and ATA Type CBY - 52208, 3 - 4 MC.

One receiver in the rack would be associated with each of the two transmitters.
The CBY-46106 receiver would serve with the CBY-52210 transmitter.  The presence of
the CBY-46129 beacon band receiver with the CBY-52208 transmitter is evidence of
training use of the aircraft, since these two units allow reception of the common
civil air communications beacon band tower-to-air frequencies (most often 278 KC)
and transmission on the common air-to-tower frequency of 3105 (later, 3023.5) KC.  

But for a typical at-sea service configuration, obtain a CBY-46105 3 to 6 MC receiver
to serve with the CBY-52208, in place of that .19 to .55 MC unit.  That 46129 receiver
would not have been used in at-sea service, especially with the ZB-3 homing adapter
and its associated 46145 BCB receiver in place.

>Also, an ATA Type CBY - 23243, Transmitter Control Box and an ATA Type CBY - 29125,
>Antenna Relay Unit were included supported by an an ATA Type CBY - 50083, 
>Modulator/Dynamotor unit.

Which, with the modification noted above, complete a very nice, classic ARA-ATA
installation.  That's significantly rarer than SCR-274-N or AN/ARC-5 installations.
I assume that three CBY-21531 receiver dynamotors and one CBY-21626 transmitter
dynamotor are present.  A list of the major ARA-ATA components are available in
a table at:  http://en.wikipedia.org/wiki/AN/ARC-5 .

>A Model ZB-3 Homing Adaptor was also removed.

That is associated with the CBY-46145 receiver.  The ZB received a 246 MC signal
modulated with a broadcast band signal, which itself was either keyed or modulated.
The ZB demodulated the BCB signal from the VHF, which was fed to the BCB 46145
receiver, which then AM demodulated the BCB signal or detected its keying with its BFO.

The ZB-3 system had a ZB antenna relay box and a ZB pilot's control box, but neither
are necessary or desirable for use of the ZB with 46145.  The 46145 should have a
CBY-62036 power adapter in the front drawer.  That should be connected to the ZB-3
to give it power.  The BCB RF output of the ZB-3 would be permanently connected
to the antenna connection of the 46145, so no antenna relay is needed.  The ARA 
control box (CBY-23251) for the 46145 would provide the only homing adapter system
controls that were needed.  

I would be most appreciative of any information that you could provide about the
homing adapter system cable connections that were present, and verification that
the ZB system antenna relay box and pilot's control box are, in fact, NOT present.

>An RT-19/ARC-4 and Mount with a C-51/ARC-4 Control Box and a J-23/ARC-4
>Junction Box were also in the aircraft.

That's excellent!  It's time capsule containing a complete early USN VHF-AM command
set.  The dynamotor is inside the RT-19/ARC-4.

So, your aircraft has an MF/HF ARA-ATA command set, a ZB-3 VHF homing system,
and the AN/ARC-4 VHF-AM command set, all apparently intact.  Pictures??

>...I cannot say for sure which of the above were only along for the ride and
>not needed during training.

I suspect all of the gear you mentioned would have had service value in a
training aircraft.  Even the ZB VHF homing system must have been used on training
aircraft to educate the pilots.

>I thought it would be interesting to pass along to the group what was found
>on this particular aircraft.

Indeed!  Thanks.

Mike / KK5F