[ARC5] Navy LM Use

[Mike Morrow]

Carl wrote:

> Here is a P2V radio install in 1962, the LM is quite prominent.
> http://www.hypertools.com/neptune.jpg

That's a great photo, Carl.  It illustrates what I was talking about
when I wrote:

>> The LM-* was even less important for the USN AN/ARC-25, which is the
>> combo of the AN/ART-13 and the AN/ARR-15.  In this system, the AN/ARR-15
>> receiver can easily be set to 1 kHz accuracy without external calibration.
>> Yet, the LM-* often appeared even where the AN/ARC-25 was installed.

And there it is in the photo...a classic AN/ARC-25 (AN/ART-13 and AN/ARR-15)
that like most had two AN/ARR-15 receivers.  None of that required an
external frequency standard like the LM-*.  And most likely, there's one
or two AN/ARC-27 UHF command sets nearby...also not helped by an LM-*.
Yet there it is, an LM-14 in all its glory!  (Ask me how I know it's an
LM-14.)

The AN/ARC-25 set could be controlled by the pilots after all the local
frequency setting and tuning was completed in many installations.  The
AN/ARR-15 would be controlled by a modern six-inch control panel 
C-733A/ARR-15A, and the AN/ART-13 would be controlled by a similar
C-740/ART-13 panel.

Notice the natural-finish BC-461 control box for the RL-42 training wire
reel at the extreme left of the photo...still in use in the 1960s.

> In the same year during the Bay of Pigs fiasco the P2V-7 carried the 
> ARC-38A, ARC-94(Collins 618-S, 618-T respectively), ARR-41, plus crypto
> and a Mite TTY.

A minor item...there are no Collins commercial equivalents to the AN/ARC-38
or -38A.  The 618S-1 uses up to 144 crystals for its frequency control,
while the AN/ARC-38 and -38A use stabilized master oscillators capable of
generating more than 35,000 channels.  The closest all-Collins equivalent to
the Collins/RCA AN/ARC-38A is the Collins 618S-1/MC, which is USB and 35,000
channels like the AN/ARC-38A, but it's a totally Collins design that had
many significant differences from the RCA USB conversion of the old Collins
AN/ARC-38 into the AN/ARC-38A.

The AN/ARC-94 (Collins 618T-2) was back-fitted into many older USN aircraft
that still retained the AN/ARC-38A as well.  The AN/ARC-94 is likely one of
the finest HF aircraft radios that have ever existed.

So that 1962 P2V-7 was as well equipted as any USN aircraft of the era.

These old photos are valuable!

Mike / KK5F