[Milsurplus] [ARC5] Soviet 1RSB-70 copy of the AN/ARC-8, Plus Other TU-4 Radio Sets
Meir WF2U
wf2u at ws19ops.com
Wed Nov 28 22:37:21 EST 2012
Mike and all,
It seems to me that the story with the patch and bullet holes copying is
true or another urban legend. It is a fact that the B-29 copies were the
TU-4's. Their engines were just as unreliable as the originals on that model
of the B-29. Many clues indicate that they got the license to manufacture
the engines, and possibly they got the license for the basic airframe as
well.
I also think, based on a lot of evidence, that the RSB-70 (not 1RSB-70), and
the US-9 were not reverse engineered copies of the original items, but they
must have gotten the plans which they have subsequently modified to conform
to their available parts, manufacturing processes and standards. They also
most likely received at least several examples of the items to get familiar
with and compare their test results with.
This happened also in the case of the Russian GAZ jeep. Many Bantam (the
Jeep's predecessor) prototypes and Ford Jeep GPW's were sent to Russia in
the beginning of the war. Since the S.U. already had a Ford factory since
the early 30's, they married the Bantam and the Ford GPW features, fitting
in many Ford car components which were readily available locally. The
original WW2 GAZ looked like a cross between the Bantam and the GPW...
The RSB-70 later became the R-807 (in the mid-50's the Soviets revised the
military equipment nomenclature and all radios got the prefix R; and the
first digit of the nomenclature number indicated the branch of service. 8xx
designates airborne radios). The US-9 receiver never got new nomenclature
for some reason... There are also some design differences between the RSB-70
and the R-807, which was manufactured until the `1970's along with the US-9
and it's remote tuning variant the US-9DM. My R-807 for example has a 1967
manufacturing date on the data plate and my US-9 was manufactured in 1966.
The RSB-70/R-807 have several mechanical differences from the ART-13. The
top coveris not fastened by Dzus fasteners like in the ART-13, but uses
hasps, and the sides of the cover extend down about 1/2" on all four sides.
Internally, the K105 relay is completely different mechanically from K105 in
the ART-13. I've never seen the first production run RSB-70 which, as you
mentioned, has the TCZ type rails. My R-807 has the same type rails as the
ART-13, although mechanically they're mounted differently - not as part of
the bottom tray, but individual rails. With this said, the R-807 very
happily fits the ART-13 shock mount. Also, the ART-13 plugs fit the R-807.
The front panel differs in that, that the flanges of the Russian meters are
different from those of the ART-13. My R-807 came with the original
calibration book. In the original Russian R-807/US-9 system the key used was
a special key, model P31V (П31В) which has a transmit/receive switch.
Regarding the US-9: again, I wasn't aware that the earliest models didn't
have the 28V line fuse on the front panel and the regulator was a neon bulb
like in the BC-348(*). I bet the knobs even on that model weren't aluminum
like the BC-348, but plastic, like on the later production runs.
There is a difference in the dial divisions between the US-9 and the BC-348:
there are no divisions between the frequency points with the numbers in the
US-9. My US-9 uses a standard, octal VR type tube (Russian SG-2S, 72 V
firing voltage) for regulating the local oscillator voltage. The tube
envelope is similar to that of a 6V6, i.e. straight tubular envelope, unlike
the US VR type tubes.
There is another improvement over the BC-348: the dynamotor base plugs into
the receiver chassis via a Jones-type plug and socket system. This is a much
neater solution than the terminal strip in the BC-348. In later production
runs the dynamotors were replaced by a solid-state inverter power supply, on
the same base plate.
On later production runs than mine, the main tuning knob with the crank was
replaced by a dual-speed planetary drive/knob.
The BC-348 shock mount and power/control plug fits the US-9 with no
problems.
Here is a photo of the Russian equivalent of the AN/ARC-8 system in an IL-14
aircraft , showing the cockpit, radio operator's and navigator's positions.
:
http://www.ruudleeuw.com/tmp-il14-tomasz01.jpg
Mike, I'd love to see that TU-4 manual...
73, Meir WF2U
Landrum, SC
-----Original Message-----
From: arc5-bounces at mailman.qth.net [mailto:arc5-bounces at mailman.qth.net] On
Behalf Of Mike Morrow
Sent: Monday, November 26, 2012 2:56 PM
To: arc5 at mailman.qth.net; milsurplus at mailman.qth.net
Subject: [ARC5] Soviet 1RSB-70 copy of the AN/ARC-8,Plus Other TU-4 Radio
Sets
Most of us have heard about the Soviet copy of the AN/ART-13 and BC-348
(AN/ARC-8) liaison set, which the radio installation and operation manual
for the TU-4 calls the 1RSB-70 system, using the 1RSB-70 transmitter and
the US-9 receiver.
The 1RSB-70 copied the early USN ATC, not the USAAF T-47A/ART-13.
Principle differences between the 1RSB-70 and the T-47A/ART-13 are:
(1) 1RSB-70 has no dynamotor control power cover interlock,
(2) 1RSB-70 has no VFO dial B vernier scale,
(3) 1RSB-70 uses the original two-tube 8Q-1 type of MCW-CFI unit,
(4) 1RSB-70 uses the ATC-type six-band LF/MF oscillator (200 to 1500 kHz)
which was a standard part provided with all early ATC COL-52286 units,
rather than the three-band USAAF O-17/ART-13A LF/MF oscillator (200
to 600 kHz) that was optional for the T-47A/ART-13.
(5) 1RSB-70 uses the original ATC-type slide rail mounting system,
(6) 1RSB-70 uses external LF/MF tank coils that are copies of ATC Navy
Type 47281 (200 to 600 kHz) and Navy Type 47282 (500 to 1500 kHz).
**Not** coincidentally, those six attributes also describe exactly the
differences between the original early ATC system and the T-47A/ART-13.
I believe that the ATC design was most likely given to the Soviets by
the US, rather than the story about the Soviets copying the units on
board impounded B-29 aircraft. Those B-29s would most likely have been
carrying USAAF T-47A/ART-13 units rather than the USN ATC, although
there remains some doubt since USAAF Radio Operator Information File
book photos in the liaison set chapter seem to show a USN ATC rather
than the USAAF's improved T-47A/ART-13. Still, it seems unlikely that
a NT-47282 (CU-26/ART-13) would have been aboard a USAAF B-29 for the
Soviets to copy for their 1RSB-70.
The Soviet US-9 liaison receiver part of the 1RSB-70 system is a copy
of the BC-348-H/K/L/R.
Also interesting is the is the MF/HF command set carried on board the
Soviet TU-4 copy of the B-29. It was...the SCR-274-N! Not a Soviet
copy of the SCR-274-N, but an actual US-made SCR-274-N set with English
control labels that the radio installation manual for the TU-4 goes into
detail to explain to the Russian reader. The US must have supplied
SCR-274-N sets to the Soviets under Lend-Lease in such quantity that it
was unnecessary to bother making a local clone.
Here's a list of other radio sets in the TU-4, from a 1950 Soviet manual:
Soviet US
System Nomenclature Equivalent
MF/HF Liaison Transmitter 1RSB-70 ATC
MF/HF Liaison Receiver US-9 BC-348-H/K/L/R
MF/HF Command Set USAAF SCR-274-N SCR-274-N
VHF Command Set 12RSU-10 SCR-522-A
Interphone Set SPU-14 RC-36
Automatic Direction Finder ARK-5 SCR-269-*
VHF Localizer Receiver KP-RUSP-45 RC-103-A
Marker Beacon Receiver MRP-45 Similar to RC-43-*
Radio Altimeter RV-2 Simplified AN/APN-1
Emergency 500 kHz Transmitter AVRA-45 SCR-578-*
73,
Mike / KK5F
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