The D649 chart recorder was used as far back as 1956 aboard HMCS Labrador. Like any piece of equipment, a radio set has a finite life expectancy with the military. As a general rule, this expectancy is twenty years. Like any other system, advances are continuously being made, however, it is not always desirable to incorporate such advances in military communications systems. The major reason for this is the cost of procurement and proof of reliability of new systems.
Radio equipment provides continuing service in peace and in war.
New radio systems are seldom fitted purely for the sake of improvement unless there are changes in NATO requirements, Canadian federal radio regulations, or amendments to International regulations. Model 15 Teleprinter, MSL5 LF receiver, PV500 HM transmitter, and the TED3 UHF transmitter. In this time period, much of the existing UHF gear faced obsolescence because it required a continuous supply of crystals, did not have a rapid tune facility, did not have 50 KHz channel spacing and suffered from a high failure rate. By 1978, the typical radio configuration aboard a destroyer was five URC 32's, seven WSC 510's, seven Racal receivers and an SRD 501. He describes some of the equipment used in the 'Silent Service' during the mid 1960's.