Was Re: [Elecraft] KX1 MAZX supply voltage There has been much discussion about kits and homebrewing in another thread, and the question about max voltage for a KX1. The KX1 is a fairly simple radio, so its possible to start to analyzing the factors that would determine max supply voltage. Of course, Don's suggestion (warning) that its best to follow the manufacturer's value is the safest. The portions of the radio that run on internally regulated voltages will be safe if the regulator input is not exceeded. The regulator input limit is pretty easy to determine. But its not quite that simple, as the voltage to the regulator is increased, so is its power dissipation. The remaining parts of the radio that get unregulated voltages would have to be evaluated individually. I'm too lazy to look up the schematic, but I suspect the final audio amplifier runs off the unregulated input. Again the specs on the device would give info on how much the input voltage to the radio could be. Nothing much fancy about that. My greatest concern would be the output transistor in the transmitter. Here things get complicated. The specs for DC voltage limits give an upper limit to supply voltage. But since we have some inductance and tuned circuits involved an AC analysis would be required. To further complicate things, the antenna SWR would come into play. Not simple at all! Once past the final stage, a look at the driver would be needed too. Well that's a beginning to the analysis. Hopefully others can add some comments and analysis. A lot can be learned from kits when you go beyond just assembly. Is it the same as designing a rig from scratch? No, not quite the same thing. But being able to really analyze design gets one close to being able to do design work.
73 - Mike WA8BXN ______________________________________________________________ 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
