Laboratory Jottings

Radio Record, Volume V, Issue 17, 6 November 1931, Page 6

Laboratory Jottings

JRC Valves -_- From Messrs. W. R. Cunningham we have received four J.R.C. valves for test. These were a 224, 227, 280, and 245 types, and although time has not permitted our subjecting them to life tests, it is apparent to us that they are good valves. The 227 was subject to tests involving it as an oscillator, and in this position it did singularly well, indicating that its dynamic characteristics were all that could be expected. Not all valves are good oscillators, though they may function well elsewhere. The 224 and 227 heat remarkably quickly, and when placed in a standard set they were in an operating condition in about half the time normally taken. Amplification and tone are up to standard, and better than some valves we have encountered. Generally speaking our tests resulted in our classing J.R.C. valves as be- _ ing equal to standard, with the exception of time required for heating the cathode, in which respect they showed an improvement. Life, it must be re membered, was not tested for, but there is no reason to believe it should be subnormal.