Wartime Civilian Receiver Codes

The Civilian Wartime Receiver was built by 42 different manufacturers, and each manufacturer was allocated a code number commencing U. The "U" numbers were known only to the wireless Trade, and enabled service engineers to identify who had made the receiver, as although the design was standard, some manufacturers incorporated minor modifications. The valves for the set were made by most of the current manufacturers, and no makers name was placed on the valve. However it was possible to tell who made the valve from a code number known to the Trade, which enabled replacements under guarantee to be made. By way of example of the coding system in operation,  Murphy Civilian Wartime Receivers were designated U7, and featured a valve line up of 21x, 24x, 26x & 27x, where x is the manufacturer's code number (see table below). For reference purposes these valves are electrically similar to UU5, OM6, EL33, OM10. 

Valve Manufacturers Code (Final Digit Of Valve Number)

1 Cossor 2 Mazda 3 Ferranti 4 G.E.C.
5 Marconi 6 Mullard 7 S.T.C.

Receiver Manufacturers "U" Code

U1 Bush U2 Ekco U3 Cossor U4 H.M.V.
U4A Marconi U5 Ferguson U6 G.E.C. U7 Murphy
U8 Philips U9 Pye U10 Ultra U11 Alba
U12 Burndept U12A Vidor U13 Central Equipment U14 Ferranti
U15 Felgate Radio U16 Hale Electrical U17 Halcyon U18 Invicata
U19 Lissen/Ever Ready U20 McMichael U21 Philco U22 Pilot
U23 Plessey U24 Regentone U25 R.M.Electric U26 Decca
U27 Dulci U28 R.N. Fitton U29 Portadyne U30 Pamphonic
U31 Mains Radio Gram U32 K.B. U33 Roberts Radio U34 R.G.D.
U35 R.S.C Radio U36 Beethoven U37 J.G.Graves U38 Aren Radio
U39 N.H. Radio U40 Ace        

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