By Thomas R. Ray, III CPBE, AMD, DRB
Tom Ray Consulting
First the Crud
NEW YORK — So I was working on this transmitter today. Seriously – I know this starts off like a joke. Problem was actually a bad air switch. All transmitters have a way to sense air flow. If there is no air flow in the transmitter, if, for example, the blower motor quits, it will shut down. In the case of a tube transmitter, this is to prevent the final amplifier deck from melting down and starting a fire. In a solid state transmitter (which also uses temperature sensing in the final amplifier), it prevents the transistors from self destructing causing a fire and/or other severe damage to the amplifier.
Anyway, this isn’t related to the air switch, but it could be (the air switch in this case was 33 years old – it simply had enough). The air filters on the transmitter were caked with crud.