[Milsurplus] BC-348 comment

[Meir WF2U]

Hue and All,

According to Russian documentation, the Russian variant of the BC-348, the УС-9 (US-9) went into mass production in 1948 in Plant 368 (Frunze). Production later was done in several other plants as well, until 1980. From 1980 to 1987 the УС-9 was manufactured in small numbers, for special orders. Total production was more than 50,000. 
In the later production runs the dynamotor was replaced by a direct  plug-in, equivalent solid-state inverter, and the main tuning knob was replaced by a two-speed planetary drive knob. 
The УС-9 has several improvements over the original BC-348R type receiver: A real voltage regulator is used for the oscillator, the main +28 VDC supply line fuse is placed in a fuse holder on the front panel, next to the dial light intensity control (the BC-348 fuse is inside the receiver, under the chassis, so the receiver has to be removed from the case to check/change the fuse). The УС-9 dynamotor and the later solid-state supply have a Jones type plug on the bottom of their mounting subchassis, which mates with the connector on the receiver chassis as the dynamotor unit is placed in its place. (The BC-348 uses lugs at the end of the wires in a harness, which have to be fastened under the appropriate screws in the terminal strip on the side of the dynamotor subchassis).
>From 1955 there was a completely remote controlled variant of the US-9, called US-9DM. It had a servo system for tuning;  band switching was done by a stepper switch, the rest of the controls were also remoted. The servo circuits were mounted in place of the dynamotor, and the receiver was powered by an external 115VAC, 400 Hz supply. Instead of the regular front panel, the US-9DM has the servo motors mounted on the front, topped by a cover. Only a local audio gain control and a phone jack (and the Cannon look-alike power connector) are on the front panel.
My US-9 has 1968 manufacturing date on it and it has the older style crank main tuning knob, and dynamotor. Incidentally, it fits the BC-348 shock mount and the power/control connector on it perfectly mates with the plug on the receiver.

73, Meir WF2U
Landrum, SC


On August 11, 2016 3:56:35 PM EDT, Hubert Miller <kargo_cult at msn.com> wrote:
>I think i read that the USSR used the BC-348 derivative US-9 until,
>what,
>early 1980s?
>
>That is a very long lifetime for a design that originated with the 1936
>BC-224-A. 
>
>I cannot offhand think of another military communications design line
>that
>had a
>
>greater longevity. 
>
>-H M 
>
>
>
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