What is the true duty cycle of a portable radio?

[needairtime]

IMHO hams are weird, they're the ones with a need for a release-to-listen button. Heck we actually hold meetings on the air... Construction workers and safety officers usually do not yak for hours at a time and hence transmitter duty cycle isn't as critical - when they need to hold a meeting, they hold a face to face meeting - though the radios are usually durable enough in case an on-air meeting is necessary once in a while.

That being said, I'd say that 25% mark is more than enough for a commercial use radio for those occasional on air meetings. For frequent ragchewing, this may be insufficient...

 

[FluxMux]

When you are talking about duty cycle for the operation of a specific function of any electronic/electrical device, even something as rudimentary as an AC arc welder... first you need time frame, then a duty cycle. Percentages mean nothing without a time frame first.

So first you would need to know that your radio can handle being keyed for, let's say 2 minutes... if your duty cycle is 25%, then you shouldn't talk for another 6 minutes per design. A properly engineered device with good documentation will give you this if it is a concern.