45 tube RCA power tubes pair black plate engraved base low watt power amplifier 

two tubes type 45 made by RCA RADIOTRON
black plate ribbed 
mono plate
hanging filament 
pan getter 
black engraved base 

tested tv7 = 58/56 ( reference good at 47/47)

also called UX-245 UX-345

VINTAGE GENUINE VACUUM TUBES TRIODE Power/Output
Great tubes for "Low Watts" Amplifier with Direct Heater Triode as last stage power output

45 = 245 = CX345 = 145 = A245 = ER45 = EX645 = UX245 = PH245 = C-245 = 445 = SX245 = MX245 = 245-C = L45 = ER245 = DX245 = PA245 = AC45 = NX245 = X245 = T45 = P245 = G45 = RayX-245 = NU-45
Similat tube  Other shape (e.g. bulb type):   M45
Sub tube:   38045 ; FX245 ; VT-45
Other class quality (otherwise equal):   536A_Boonton ; CV610
First Serie Mar.1929 Saga of the Vacuumtube, Tyne page 322.
45 is the evolution of     71A  
Evolution of 45 is 2A3  45spec VT-52  
Socket    UX-Base 4 Pins 2 thick
Filament Heater Vf 2.5 Volt / If 1.5 Ampere / Direct / Parallel, ~ = (AC/DC)
According to Tyne, page 322, this audio-power output tube was introduced in March 1929. It is intermediate between UX171A and UX210 and was first named UX245, later in short 245 and 45. See other identical denominations too. The oxide-coated filament operates at 2.5 volts AC or DC, taking 1.4 amperes. The anode is of sheet nickel, carbonized to facilitate radiation. Power output about 0.8 watt.
"Development was started by Westinghouse in June 1928."


box 131