[FM TRANSMITTERS ] [ AM & SHORT WAVE TRANSMITTERS ] [ HIGH PERFORMANCE FM EXCITERS ] [ NEW PRODUCTS ] [ TV & RADIO SYSTEMS ] [ INTERNET PRODUCTS ] [ WORLD WIDE MIF ]

 

High Power FM Broadcast Transmitters

CCA has manufactured reliable FM transmitters for over 30 years. High quality, conservatively-rated components, and innovative circuit designs have given CCA the best, "time proven," track record for reliability in the world. Because of their simplicity these transmitters are very easy to diagnose and repair.
CCA pioneered the Grounded Grid Design for FM Broadcasting. This design eliminates the need for grid bias and screen voltage power supplies. Neutralization is not required. Conventional power supplies, relay controls, and grounded grid circuitry make CCA FM transmitters very immune to the hazards of a typical transmitter environment.

General
The transmitter is in one cabinet with an external low pass filter and directional coupler. Air enters the transmitter through the front and rear air filters and is exhausted through two ducts on the top. The air filters can be removed for cleaning while the transmitter is in operation.

Exciter (FM 60G or FM 100GS)
CCA FM Broadcast Transmitters use a frequency synthesized, direct FM exciter. The CCA model FM60G or FM 100GS Exciters feature high audio performance and a rugged, broad-banded FET 60 or 100 watt power amplifier. CCA Exciters yield performance specifications compatible with the most demanding processing and digital source material.

Intermediate Power Amplifier (FM 20000GZ and FM 25000GZ)
A grounded grid 3CX1200Z7 is used with a broadband, cathode-driven input. The triode IPA with a triode PA provides a reliable and stable transmitter with impressive specifications.

Intermediate Power Amplifier (FM 30000G)
The IPA is a conservatively-operated 5CX1500B pentode. The relatively high rf drive power requirements of the cathode driven triode PA stage make the pentode IPA the most cost-effective, efficient, and durable choice. It offers high gain, small space, and does not require neutralization.

Power Amplifier
The PA tube, a triode in a DC grounded grid/cathode driven configuration, provides long tube life, inherent stability and reliability. The FM30000G uses the Eimac 3CX20000A7. The FM20000GZ and the FM25000GZ use the 3CX15000A7. The CCA output design employs strip-line topology in a low Q, broadband configuration. The output is tied directly to ground, providing a D.C. path for harmless dissipation of static charges associated with lightning. This design reduces the undesirable effects of narrow bandwidth and high circulating currents exhibited by cavity resonators. The broadband cathode-driven input is less critical to tune. AM synchronous noise is the lowest in the industry.

Control/Overload
An easy-to-understand relay control system is used instead of complex microprocessor controls and diagnostic systems. Relays are still the best method for transmitter control in the harsh RF environment. Rugged, plug-in relays control all functions. For safety and ease of troubleshooting, no dangerous voltages enter the control compartment. Control circuitry can be safely and easily serviced while the transmitter is in operation. The design incorporates automatic, three-cycle overload recycling to protect the tubes and major components. VSWR power fold-back circuitry automatically reduces transmitter power during antenna icing conditions. If a momentary A.C. power main failure occurs (seven seconds or less), the transmitter will return to power immediately without the standard warm-up sequence. A two-minute cool-down period in the automatic shutdown sequence extends tube life. Extensive use of meters and control lamps are provided for operator convenience. Status, overload, VSWR and auto-power indicators are all available on the front panel. The 24 VDC control system interfaces with any standard remote control (Automatic power control and VSWR foldback is provided).

Power Supplies
Conventional, conservatively-rated, easy-to-understand power supplies are used. They are designed to withstand extreme temperatures, line variations and surges.
FM THD less than 0.05%

Model Type Notified Power Levels
FM20000GZ 10KW-22KW
FM25000GZ 12.5KW-27KW
FM30000G 25KW-38.5KW

Frequency Range: 87.5-108MHzBROutput Connector: 3 1/8" EIA
Ambient Temperature: 0 degrees C-50 degrees C
Altitude (High Altitude Option Available): 7,500 ft.
AC Voltage Requirements: 200 to 240 Volts 60Hz(Other Voltage Configurations Available)
Harmonics: better than 80db below carrier
AM Noise (residual): better than 60db below carrier
AM Noise (synchronous): better than 55db below carrier
FM Noise: better than 80db below carrier
FM THD: less than 0.05%

Tube Complement
FM20000G, FM25000G: 1 ea. 3CX15000A7
1 ea. 5CX1500B
FM35000G, FM27500G: 1 ea. 3CX20000A7
1 ea. 5CX1500B

Mechanical Characteristics (typical)
Weight Net: 1,700 lbs. (771 Kg.)
Shipping Weight: 2,000 lbs. (908 Kg.)
Shipping Mass: 73 cu. ft. (2.14 cu. M)
Dimensions: 71" H x 38" W x 34" D
* Single phase requires two cabinets.