[ARC5] [Milsurplus] Soviet 1RSB-70 copy of the AN/ARC-8, Plus Other TU-4 Radio Sets

[Meir WF2U]

Mike,

I remember sending you a copy of the calibration book to compare it with
that of the ART-13A. It must be close then to the original ATC calibration
book - the R-807 (mine is 1966 vintage) doesn't have the vernier scale over
the VFO dial B, just like on the ART-13 / ATC. However, it has the later, 3
tube MCW-CFI unit, with a somewhat different layout, but the same tube
line-up as on ART-13's, with the Russian equivalents. Here the crystal is a
cylindrical unit (all the Russian crystals I saw are tubular in shape), and
instead of it being mounted towards the rear edge of the subchassis, the
transformer is there, and the crystal is in the middle of the chassis.
Regarding the mounting arrangement: The rails are not part of an ART-13 type
bottom plate with the calibration book riveted to it (MT-283); there are two
separate rails individually held by screws to the bottom of the R-807. The
calibration book pocket is also a separate piece screwed directly to the
bottom of the transmitter. The arrangement slides into the MT-284 and fits
perfectly; the front hold-down knurled nuts fit and tighten perfectly on the
R-807 rail. The rear studs of the transmitter also fit the rear holes of the
MT-284 with no problem. I haven't tried to switch the rails from side to
side, but the channels themselves look the same, and the little slopes on
the front flanges are aligned the same way as on the MT-283. I suppose
they'd still fit if I interchanged them from side to side, but I don't know
whether the tie-down nuts would fit the rails the same way. I have to look
on both the R-807 and the ART-13 whether they're symmetrical.
The LF unit in my R-907 is the 200-1500 kHz, 6 band unit, a la ATC...

I'm questioning the 1 prefix you see in the TU-4 manual with the RSB-70... I
never saw the 1 before. Everywhere I can find references for the RSB-70 it
doesn't have the 1 in front of it. There are other transmitters in the RSB
series and none of them has a 1 prefix when I look at the list on a Russian
website. 

Look at http://www.ruudleeuw.com/temp-petrykowski-il14.htm see the radio
operator's position in full screen, you'll see the key I mentioned. 

73, Meir WF2U
Landrum, SC

P.S. I'd like the copy of the pages you mentioned from the TU-4 manual!
Thanks!


-----Original Message-----
From: milsurplus-bounces at mailman.qth.net
[mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Mike Morrow
Sent: Thursday, November 29, 2012 3:06 PM
To: arc5 at mailman.qth.net; milsurplus at mailman.qth.net
Subject: Re: [Milsurplus] [ARC5] Soviet 1RSB-70 copy of the AN/ARC-8, Plus
Other TU-4 Radio Sets

Meir wrote:

> 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.

I think that this is exactly what happened.  It is clear that the 1RSB-70 is
patterned very closely on the early USN ATC, not the later USAAF
T-47A/ART-13.
BTW, my 1950 Tu-4 radio manual refers in *every one* of hundreds of
reference to
the "1RSB-70" as both the nomenclature for the whole MF/HF liaison set
system
(including the US-9 receiver) *and* and for the transmitter itself.  

> ...I've never seen the first production run RSB-70 which, as you
mentioned,
> has the TCZ type rails.

TCZ rails are the same as early ATC mounting rails, for which the stationary
part received the JAN MT-161/ART-13 designation.

> 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.

The JAN nomenclatures for these types are MT-283/ART-13 for the movable part
(mounted on bottom of transmitter) and MT-284*/ART-13 for the stationary
part
(mounted on aircraft).  I suppose that the Soviet versions better suited
their needs.  Is the right-side mount interchangeable with the left-side?

> My R-807 came with the original calibration book.

You sent me years ago a copy of a page from that.  IIRC, the tabulated data
for any one frequency was close, but not exactly the same, as that shown in
the US equivalent.  It was provided only in 5 or 10 kHz increments, unlike
the 1 kHz increments possible with the VFO dial B vernier scale found on
the T-47A/ART-13.

Some questions about the R-807:

(1)  Does it still use the original two-tube 8Q-1 style MCW-CFI unit?
(2)  Does it have the LF/MF oscillator, and if so is it the ATC-style
     200 to 1500 kHz unit, or a 200 to 600 kHz O-17/ART-13A style unit? 

> 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.

The key pictured in the 1950 Tu-4 radio manual appears to be identical to
the
US J-37 key.

> 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.

It's hard to tell from the manual's photographs...the smaller knobs are
styled
differently from the BC-348's, but the main dial tuning knob appears
identical
to that of the BC-348-*.

> There is another improvement over the BC-348: the dynamotor base plugs
into
> the receiver chassis via a Jones-type plug and socket system.

The schematic of the early US-9 seems to show a terminal exactly like that
on the BC-348-H/K/L/R.  I'd expect that, for other than the AF output tube
being a 6V6 (with associated filament resistor alteration), the early US-9
seems electrically and mechanically identical to the BC-348-H/K/L/R.

I'll send you (and anyone else interested) an eight-page pdf of scans of
several pages from my Tu-4 radio manual that deal with the 1RSB-70 and the
US-9.  It'll be under a separate e-mail, and is 5 MB in size. 

73,
Mike / KK5F
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