Wow--I received a plethora of responses, all pretty much saying what Don's said here - external 13.8 power supply will yield just about 4 watts. Internal batteries, which are only going to run around 9v (6 x 1.5 = 9) will only crank out around 2 watts.
Many thanks for the help. I'm dutifully saving up for my first Elecraft, which will be the KX1. I'm hoping to have a nice project for the holidays! 73's, John O. K7JTO On Sat, Dec 4, 2010 at 4:27 PM, Don Wilhelm <[email protected]> wrote: > John, > > The power output of the KX1 is dependent on the power supply voltage. > A well constructed KX1 will normally deliver 4 watts on 80, 40 and 30 > meters, and 3.5 watts on 20 meters with a 13.8 volt power source. Some will > do a little better and some a bit worse than that target figure. > > The voltage produced by the 6 internal cells is less than 13.8, and the > exact voltage depends on the battery type. Lithium batteries normally are > the best if the power level is important to you, with alkalines running in > second place. NiCad or NiMH batteries will produce lower voltages and > therefore lower power. To get to that 13.8 volt level, each of the 6 AA > cells would have to produce 2.3 volts. > > But yes, as a general rule, 2 watts is to be expected when using the > internal batteries. There is just not enough room to pack additional > batteries inside. > > A few KX1 owners have modified the KX1 to use rechargable Lithium Ion > batteries which produce a higher voltage (and more power as a result). > > I want to offer a caution - running the the KX1 at greater than 4 watts can > cause damage to the components following the PA amplifier - with a good 50 > ohm pure resistive load, one can go a bit higher without harm, but as the > SWR increases, the voltages in the low pass filter will also increase and > could exceed their voltage ratings. > In other words, don't try to push the KX1 power too high - the difference > between 3.5 watts and 5 watts is almost imperceptible on the receiving end. > > 73, > Don W3FPR > > > On 12/4/2010 4:20 PM, John Overbaugh wrote: > >> In researching the KX1, I thought I had read that it's possible to get 4 >> watts of output. However, the manual shows 2 watts as the max from >> internal >> batteries. Is 4 watts possible? Does it require external batteries? >> >> -- John Overbaugh blog: http://kf7dvj.blogspot.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
