[Milsurplus] CRV-46123...what is it?...

[Mike Hanz]

Morrow, Michael A. wrote:
 > Of course, I should actually had written "more modern" instead of
 > "more capable."  But automatic DF with electronic loop and remote
 > indicator positioning of the SCR-269 seems to be an important
 > capability that the DZ lacks.

Completely agree, by that measure of success.  Sandretto records the 
first ADF patent as being applied for by Mosely on 22 Oct 1937, but by 
the date of Morgan's 2nd edition in 1941 there were competing receivers 
by RCA, Lear, Sperry, and Bendix, just to name a few.  I wonder if the 
Navy's hesitation to use them stemmed from their low signal performance, 
which apparently was spotty.  The Navy's stomping grounds in the vast 
reaches of the oceans tended to make DFing on weak stations a matter of 
necessity.

 > I suspect the only aircraft which could use a DZ would have been a
 > large, well-crewed craft like a PBY.  The DZ is labor intensive to
 > use, and it can't actually be operated or directly utilized by the
 > pilot.

Definitely - a navigator was required, which limited its use to the big 
patrol aircraft.

 > I have a Bendix-made USAAC BC-310 (1937 contract date, SCR-242) which
 > seems well advanced over the USN DZ, which was made well into the
 > early 1940s, judging from contract dates in my DZ-1 manual copy.

Who knows?  The NRL history states that the DZ was specifically 
developed in 1939 to provide bearings at long ranges, and the test 
report on the XDZ was dated Nov of 1939, so certainly the ADF technology 
was available but obviously not used.  It goes on to say, "A feature of 
this series was the use of very-low-impedance loops, which avoided the 
loss incurred in the condensation of water vapor on the earlier high 
impedance loops."  If you think the DZ-1 and -2 look antiquated you 
should see the original 1939 DZ before RCA cleaned it up.  Reminds me of 
a submarine dive station.

 > I never understood the reason for the common use of the completely
 > manual DF MN-26 with its hand-cranked loop and mechanical
 > spline-coupled indicator.  Maybe the MN-26 was the set of choice when
 > 400 cps AC wasn't available.

Might well be - though low signal performance might also be a factor.

 >> a tour through the NRL history books will likely show a
 >> significant program for DF and ILS far earlier than the US Army -
 >> and they were worried about locating and landing on a much smaller
 >> landing field than the AAC/AAF!
 >
 > But what examples are there of the equipment the USN developed or
 > used?  I've seen no USN equivalent to the USAAF ILS/MB sets, which
 > are very commonly found.  Did the USN use the RC-103/ARN-5/RC-193
 > (and SCS-51 on the ground) systems of the USAAF when such capability
 > was needed?

I'm not attempting to carry the Navy's banner in this, but significant 
programs don't always translate into thousands of pieces of equipment 
out in the fleet.  The Navy environment was a bit different, and it was 
1945 before they had a system that they considered adequate to land on a 
pitching, rolling postage stamp of a flight deck on a completely blacked 
out carrier.  I don't think it became fully operational until after the 
war.  With the focus on the carriers, I guess they didn't worry as much 
about landing on big, stable landing fields.  A Navy or Marine pilot 
would probably say the AAF pilots were wusses to need ILS for a 5,000 
foot runway.  :-)

 >> As an interesting aside, the ARR-1 was a standard piece of gear on
 >> AAF aircraft later in the war.  Also known as the ZB-*, the AAF
 >> must have considered it useful for something...  :-)
 > I've wondered where and how commonly that occurred.  It's hard to
 > find much info on what the USAAF really did with all those BC band
 > BC-946 receivers.  But most of the ARR-1 sets I've seen or owned have
 > USAAF contract numbers on them, so the USAAF must have had some
 > intent to use the system.  One suspects the USAAF use of the ARR-1
 > and BC-946 sets must have been mainly in the Pacific Theater.  But
 > then, what associated ground set did the USAAF use, or intend to use?
 > The USN's YG set??  I don't think there's a JAN- or SCR-nomenclature
 > equivalent of a YG-type of homing transmitter.

They certainly seem to be more common on the AAF aircraft sent to the 
Pacific theater, so homing toward Navy bases were probably their main 
operational use.  I know there's one listed in the 1943 illustrated 
parts book for the B-29.

 > I still think the best
 > airborne HF receiver (BC-348) and ADF receiver (SCR-269 and ARN-7) of
 > WWII had, at least officially, a USAAF pedigree on them.

I don't think I'll touch that one...it's too late in the evening.  :-)

73,
Mike