ICAS vs. CCS in BALUN or LINE ISOLATOR power specifications
ICAS = Intermittent Commercial and Amateur Service
as compared to
CCS (Continuous Commercial Service).
These two service types were first defined in the power-tube industry. The classical definitions are as follows:
Continuous Commercial Service (CCS) is defined as that type of service in which long life and reliability of performance under continuous operating conditions are the prime considerations.
Intermittent Commercial and Amateur Service (ICAS) is defined to include the many applications where the transmitter design factors of minimum size, light weight and considerably increased power output are more important than long tube life. In this service, life expectancy may be one-half that obtained in Continuous Commercial Service.
Under the ICAS classification are such applications as amateur transmitters, and the use of devices in equipment where transmissions are of intermittent nature. Intermittent operation implies that no operating or ‘on’ period exceeds 5 minutes, and every ‘on’ period is followed by an ‘off’ or standby period of at least the same or longer duration.
As applied to passive amateur radio products like BALUNs, LINE ISOLATORS, FILTERS, COAXIAL CABLES and ANTENNAS, ICAS does not imply reduced device life, as these devices are not regarded as consumables. Rather, ICAS in a such environment implies de-rating to keep the product’s temperatures within their maximum ratings. Thus, ICAS suggests a limited operating or ‘on’ period followed by an ‘off’ or standby period of at least the same or longer duration, whilst CCS assumes continuous, key-down operation at reduced output .
As ON7FU BALUNs, UNUN’s and LINE ISOLATORS products are intended uniquely for amateur radio use, power specifications are stated, according to the ICAS approach.