TUBE 845

GENERAL DESCRIPTION


photo 845 The 845 is a low-mu transmitting triode of the thoriated-tungsten filament type designed specifically for use as a class A audio-frequency amplifier and modulator. It may also be used in class AB1 audio service. Two 845's in this application are capable of delivering approximately 115 watts of power with very low distortion.

Typical operating conditions for a single 845 in class A service are: D-c plate voltage, 1250 volts; grid bias, -195 volts; d-c plate current, 80 ma; and undistorted power output, 30 watts. Typical operating conditions for two 845's in class AB1 service are: D-c plate voltage, 1250 volts; grid bias, -225 volts; zero-signal d-c plate current, 40 ma; maximum-signal d-c plate current, 240 ma; effective load resistance (plate-to-plate), 6600 ohms; and maximum-signal power output, 115 watts.

The 845 is one of RCA's three famous "50-watters". It has maintained its reputation for long, reliable service through the years of radio communication. For real audio power with low distortion, The 845 is the answer.		 picture 845


TECHNICAL SPECIFICATIONS
ELECTRICAL
Filament
 Voltage
 Current		 Thoriated Tungsten
10 a-c or d-c volts
3.25 amp.
Amplification Factor 5.3
Direct Interelectrode Capacitances
 Grid to Plate
 Grid to Filament
 Plate to Filament
13.5 μμF
6 μμF
6.5 μμF
MECHANICAL
Maximum Overall Length 7-⅞"
Maximum Diameter 2-5/16"
Bulb T-18
Base Jumbo 4-Large Pin
Socket Type UT-541
Specifications may change without notice

THIS TUBE IS USED IN THE FOLLOWING SHORTWAVE BROADCAST TRANSMITTERS
Manufacturer Transmitter specifications Power in kW
Collins 231D-20 3
Continental Electronics 420 A 500
Gates HF1 1
HF-5 / HF-5 B 5
HF-10 / HF-10 B 10
HF-20 / HF-20 B 20
RCA ET-3656A 1
ET-4750 7.5


THIS TUBE IS AVAILABLE FROM
Manufacturer Rebuilder Distributor





PRICE LEVEL (US$)
1 2 3 4 5 6
0 - 10 10 - 100 100 - 1000 1000 - 10,000 10,000 - 50,000 50,000 - 100,000