A push-to-talk rating system

This rating system (one minute maximum ON and four minutes minimum OFF) recognizes the trend toward shorter transmission time and higher power without impairing the useful service life of the tube. Continuous operation under these conditions is not to result in catastrophic failure. The mechanisms of failure are discussed. Existing types can be re-rated wlth an approximate increase in power output of 30%; the actual value varies greatly according to the conservatism of the basic design of each tube. New tubes designed especially for Push-to-Talk Service with such features as high thermal inertia anodes have shown that as much as an 80% increase in power output can be obtained with respect to the prototype.