CONTINENTAL ELECTRONICS 418 D-2

GENERAL DESCRIPTION

AM Broadcast Transmitter Type 418 D-2 100 kW SW

photo Continental Electronics 418 D-2

General Description

The 418D-2 is a continuous coverage 100,000 watt AM transmitter designed for A3 operation in the international short wave broadcast bands (2.3 to 26.5 MHz). All power tubes are tetrodes, and all power supplies use solid state rectifiers. Final amplifier and modulator tubes are Eimac Type 4CV100,000C vapor-cooled tetrodes that operate at 70% and 25% respectively of their capability at 100% modulation. The 4CX3000A tetrode is used in the rf driver amplifier. Solid state amplifiers are used in the low level audio and rf stages.

All transmitter control and monitoring can be accomplished from a single front panel. Fast frequency change is provided with selection of up to 10 pre-selected frequencies. Tuning transmitter to a new frequency is extremely easy since only five tuning controls are used. After tuning is once accomplished and set as one of 10 preset channels, it can be retuned by activating the appropriate channel without further manual retuning. A vapor system cools the final rf and modulator amplifiers, and forced air cooling is used for the low level tube.

Continental's 418D-2 provides consistently high-quality broadcast service and combines simplicity of operation with minimum maintenance.

TECHNICAL SPECIFICATIONS
Carrier Output	100 kW
Type of Modulation	High level plate
Type of Emission	A3
Frequency Range	3.2-22 MHz (2.3-26.5 MHz on special order)
AF Input Impedance	600/150 ohms balanced or unbalanced
AF Input Level for 100% Sine Wave Modulation	+10 dBm ±2 dBm @ 1 kHz
AF Response	±1 dB 50 to 7,500 Hz @ 90% modulation
AF Distortion	Less than 3% RMS 50-7,500 Hz @ 90% modulation
Carrier Shift	Less than 3% not including line variations
Modulation Capability	100% positive and negative peaks 50-7,500 Hz Sine
Residual Carrier Noise	55 dB (unweighted) below 100% level at 1 kHz
RF Harmonic Output and Spurious Response	Complies with CCIR regulations
Output Impedance	75 ohms unbalanced (300 ohms balanced optional); max. VSWR 1.5:1
Power Source	360-480v, 3 phase, 50/60 Hz (other on special order)
Power Factor	Better than 0.9
Power Consumption	Carrier-unmodulated: 175 kW Carrier-modulated: 100% Sine wave, 275 kW
Altitude	6,000 feet (1.83 Km)
Relative Humidity	95%
Ambient Temperature Range	41°F to 122°F (+5°C to 50°C)
Exciter	Any suitable exciter with 1/2 watt output, 2.3-26.5 MHz
Dimensions: Main Cabinet Group	Width 16' (488 cm) Depth 5' (152 cm) Height 7' (213 cm)
Power Supply Vault: (Approx.)	Width 16' (488 cm) Depth 6' (488 cm)
Weight	Packed for export 25,000 lbs. (11,340 Kg)
Cubic Volume	2,000 cu. ft. (56.63 cu. meters)
Specifications may change without notice

TUBE COMPLEMENT
RF stages		AF stages and modulator
Number	Type	Number	Type
1	4CV100,000C	2	4CV100,000C
1	4CX3000A

THIS TYPE OF TRANSMITTER IS INSTALLED IN THE FOLLOWING COUNTRIES
	ITU	Country	ITU	Country
	AUS	AUSTRALIA	CTR	COSTA RICA
	D	GERMANY	ISR	ISRAEL
	KOR	KOREA SOUTH	LSO	LESOTHO
	MDG	MADAGASCAR	OMA	OMAN
	PHL	PHILIPPINES	TWN	TAIWAN
	USA	USA