Posted by
John Lonigro on
Jun 12, 2004; 2:03pm
URL: http://elecraft.85.s1.nabble.com/FW-K1-Battery-Question-tp367714p367716.html
Hi Dan:
As I wrote the reply, I was thinking that 40% duty cycle was way too
high, because, as you say, there's lots of dead time even while
transmitting, but I figured the example would show John how to go about
estimating the life of his battery using his own guesses.
There are lots of unknowns involved. I have no idea what power setting
he uses, how efficient the K1 transmitter is, his SWR, etc. My K2 draws
anywhere from 1.5-2.4 Amps at 5 Watts into a dummy load, depending on
the band. Another thing not factored in is the 4.0 Amp Hr battery
rating assumes a 20 hour discharge. A 1 Amp load would finish off the
battery in less than 4 hours. Battery temperature is also a factor, but
not so much in the Summer.
In my case, I'm sure I'd be asleep well before the battery died.
Thanks for the clarification. I should think twice before I hit the
send key. This group's too smart!
73's
John AA0VE
Dan Barker wrote:
>Actually, the 40% Tx duty is only 50% key down (there's spaces betewwn the
>elements). So, you use .2 for the Tx factor.
>.8 Ir + .2 It = .24 or 16 hours.
>
>Now, after you work the 9 hours, you might fall over and hit your head on
>the key, and then the CW duty cycle goes to 100%. But the Tx duty cycle
>would go to 100% also, and you'd be off the air sooner. Not that it matters
>much as you are napping on the key<g>.
>
>Dan / WG4S / K2 #2456
>
>
>
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