How The World Communicates

418G-DRM 100 kW Shortwave Broadcast Transmitter  
Download this PDF file for complete product information.
  Sales Support
Our salesmen are all knowledgeable and experienced shortwav experts who can help you make the best informed buying decisions.
  Technical Support
Continental has 24/7/365 parts and product support. You can always reach a continental professional. You can even place critical parts orders on-line.




Specifications-- 418G-DRM 100 kW Shortwave Broadcast Transmitter

Modes of Emission
A3E and DRM, Standard, SSB Optional
Modulation Method
High efficiency all-solid-state step modulator using EER for AM/PM Modes
Audio Input Requirements
Adjustable from -8 to +10 dBm for 100% AM modulation
Audio Input Impedance
600 ohms, balanced. Other impedances on special order
Audio Response (A3E)
+1/-1.5 dB from 50 Hz to 7500 Hz at 70% modulation
Audio Harmonic Distortion (A3E)
Less than 3.0% at 50-90% modulation from 50 to 7500 Hz
Carrier Noise
-56 dB, unweighted, referenced to 100% modulation with a 1 kHz tone
Controlled Carrier Level Modulation (CCM)
The Type 418G DRM Transmitter has the capability of operating with variable carrier power. This
technique scales the amplitude of the carrier to the percentage of modulation. The carrier can be
reduced as much as 6 dB below the rated value without audio distortion and can be a major cost
saving to the user
Modulation Capability
100% sinusoidal modulation at frequencies from 50 to 7,500 Hz, for ten (10) minutes per hour. Up to
70% modulation on a continuous basis
RF Output Power (DRM)
50 kW RMS, 400 kW PEP with 9 dB Crest Factor
DRM: Meets all IEC PAS62272-1 & ETSI REF.ES 201 980 V.1.2.1 2002-07 specifications
See the exciter brochure for a full list of features. DMOD3 DRM Exciter is totally integrated into
the transmitter
DRM Modes
All DRM 9 kHz and 10 kHz bandwidth modes are supported
MER (Modulation Error Rate)
-30 dB, or better
SSB Option
RF Output Power (H3E and R3E)
200 kW PEP Two-Tone
High Efficiency
H3E and R3E (LSB, USB and ISB) using EER (Envelope Elimination and Restoration)
Intermodulation Distortion (H3E & R3E)
At least -35 dB relative to either tone of a two-tone test signal
Carrier Reduction (H3E & R3E)
-6 dB to -24 dB relative to full carrier or full Carrier suppression
RF Carrier Output Power (A3E)
100 kW (400 kW PEP) on all frequencies through the 3.90 to 22 MHZ range
Reduced RF Carrier Output Power (A3E)
25 kW - 100 kW
Power Source
Customer specified: 360-480 VAC, 50/60 Hz, 3-phase, other voltages available on request
The overall efficiency of the Type 418G DRM Transmitter measured as an average of ten
frequencies over the range of 3.9 - 26.1 MHz at 100 kW carrier power level will not be less than
67% with any depth of modulation. (Lower at lower power levels)
Frequency Range
3.9 - 22 MHz continuous in 100 Hz increments. 3.9?26.1 MHz, optional, 2.3 ? 16 MHz, optional
Tuning Time
An average of 10 typical frequency changes takes less than 30 seconds each
Standing Wave Ratio
Rated for 2.0:1 VSWR at full power or any customer selected VSWR below 2:1
RF Output Impedance
300 ohms balanced (Standard);
50 or 75 ohms unbalanced Optional
Carrier Level Shift (A3E)
Less than or equal to +/-3% shift at 100% tone modulation with 1 kHz sine wave exclusive of power line variations
RF Spurious
Less than 50 mW. Out of band emissions in compliance with CCIR 328-5
Ambient Temperature Range
(+5 to +45 degrees C)
Outdoors: +14 to +111 degrees F
(-10 to +45 degrees C)
Relative Humidity Range
0 to 95% relative humidity, non-condensing Altitude Up to 6,000 ft. (1,829 m) above sea level
Water, heat exchanger (supplied), and air cooling