Radio Receiver R-1051/URR

Country: United States of America (USA) Manufacturer/Brand: MILITARY U.S. (different makers for same model)
Year: 1972 – 1986 ? Type: Receiver used for civil commercial purposes, e.g. point-to-point maritime or aviation communications, used or second hand sets often used by radio amateurs. Often used also for military communications, partly special variants to military specifications.Communication Receiver (also Amateur) Mod.-ID = 113449 previous | Result List | next | New search for Radios etc. Schematics etc.: 0 (for members) Principle Double or triple conversion superhet.
Doppelsuper oder (manchmal nur teilweise) Dreifachsuperhet.
Der Apparat verfügt über zwei Oszillatorsysteme auf zwei verschiedenen Zwischenfrequenzen (ZF). Dieses Prinzip gibt es bei Rundfunkempfängern aus Preisgründen sehr selten, doch bei kommerziellen und Amateurgeräten besserer Qualität ist das Verfahren öfters anzutreffen. Sinngemäss gilt das auch für Dreifachsuper und Kombinationen davon. Superhet, double/triple conversion
Wave bands Bitte geben Sie die Wellenbänder an, falls Sie mehr wissen.Wave Bands given in the notes.
Power type and voltage AC set plus voltage range.
/ = 2 different voltages
- = voltage from-to
* = «Special»
Apparareil à courant alternatif. Tensions mentionnées.
/ = 2 Spannungswahlen
- = von-bis
* = Fabrikwahl/«Spezial»
Trafo ist nicht immer mit Primär- undSekundärwicklungen versehen. Dadurch kann das Chassis ein gefährlichesPotential führen.Alternating Current supply (AC) / 115 Volt
Loudspeaker/pwr.out This set has no built-in loudspeaker. It requires a separate loudspeaker or headset - or the set has no speaker output (not a radio).
Cet appareil n`a pas d`haut-parleur.
Das Gerät verfügt nicht über einen eingebauten Lautsprecher - entweder weil er nicht nötig ist (Gerät hat keine Tonwiedergabe) oder weil er separat zu stellen ist - bzw. das Gerät ist für Kopfhörerbetrieb.- For headphones or amp.
from Radiomuseum.org Model: Radio Receiver R-1051/URR Material Metal case.
Caisse en métal.
Gerät, dessen Gehäuse aus Metall gefertigt ist. Es kann sich um verschiedenartige Metalle und Oberflächenbearbeitungen handeln. Ist es hingegen nur ein Chassis, so erhält das Gerät eine andere Bezeichnung.Metal case
Shape Rack
Dimensions (WHD) 450 x 180 x 510 mm / 17.7 x 7.1 x 20.1 inch
Valves / Tubes 2: 6BZ6 (more for members)
Transistors There are transistors, but the number is unknown: (more for members)
Notes The R-1051/URR is one of the latest communication receivers still using vacuum tubes. The receiver is a triple conversion, digitally tuned superheterodyne capable of receiving LSB, USB, ISB, FSK, AM and CW emissions over the 2 to 30 MHz frequency range. The frequency stability is better than 0.01 ppm per day and the accuracy better than 0.05 Hz at 5 MHz. First IF 20 to 30 MHz, second IF 2.85 MHz, third IF 500 kHz.

The receiver joins quite exceptional performances to a marvellous modular execution, with the RF unit containing the several tuning turrets, the external one is motor driven. The exceptional frequency stability is based upon an internal 5.0 MHz frequency standard reference (An external standard may be selected) and a synthesizer, phase locked to the reference, also containing an error canceling loop. Various revisions built in the years, with increasing tuning resolution. Depending upon the revision, varies the quantity of semiconductors (Transistors and even ICs) used.

Mainly made by Genral Dynamics.

This model was suggested by Emilio Ciardiello.

Internal view. Bottom left: the RF preselector, with the two tubes. Bottom right: the synthesizer, which also includes the spectrum generator and the RF translator. Top right: the frequency standard and the two IF amplifiers. This receiver was manufactured in Italy by Elmer.

View of the RF module with cover removed. The large green rotary turret, holding the 1Mc/s band tuning strips is driven by the DC motor visible in the bottom left corner. Inside the turret there are two stacks of rotating wafers, carrying the tune capacitors for the Kc/s steps.

More pictures

No further information on

Radio Receiver R-1051/URR (MILITARY U.S. (different makers for same model))