The conduction cooling of power tubes in vehicular communication equipment

The anode dissipation of the power amplifier tube is one of the largest sources of heat in vehicular commmunication equipment. If this heat is not removed from temperature sensitive areas of this equipment, performance will be adversely affected. This paper describes circuits which fulfill both the electrical and thermal requirements of vehicular power amplifiers. The advantages and disadvantages of radiation, forced air and conduction cooling are contrasted and it is shown that a properly designed conduction cooled system can combine the advantages of all cooling methods. The design and performance of practical conduction cooled circuits at the 100 watt power level from 50 to 1200 Mc is discussed. Data covering pertinent thermal properties of insulators and metals commonly used in conduction systems are given.