On 2/5/2011 2:20 PM, NL7VL wrote:
I know that with CW you are actually looking at a 50% duty
cycle
That assumes that you transmit 100% of the time, which is certainly not
the case. Rather, most of us listen more than we transmit, except,
perhaps, during contests. So for CW, a duty cycle on the order of 30%
is pretty conservative.
but I'm not sure about SSB.
The peak to average ratio of highly compressed speech is on the order of
10dB, which is a 10:1 power ratio. If you subtract 2dB to account for
varying efficiency of the output stage at different power levels, you're
at 8dB, which is roughly 6.3:1 ratio. Applying a 50% listening factor,
you're at an 8% duty cycle.
In all of those cases, I'd increase the current requirement by 10% to
account for efficiency of the battery itself.
73, Jim Brown K9YC
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