Ed, First welcome to a great hobby.
I would advise against using that 'old AC adapter' - those wall warts are usually not regulated and the no-load voltage often soars to 1.5 times the voltage shown on it, and at high current loads, the voltage sags a lot. For home station use, you will likely accumulate several things that run on a "12 volt" power source - that is actually a 13.8 volt power source, the voltage of a fully charged lead-acid '12 volt' battery like that found in an automobile. So my recommendation is that you get a regulated power supply that is rated for at least 3 amps (I would actually suggest one that is rated at 12 amps or more, you will eventually need it). Put a 2 amp fuse in the power cord to the KX1 to protect it near its maximum current draw plus some reserve. As for the antenna, there are several choices to make - what bands do you wish to use it on? Is this an antenna for portable use or will it be a permanent part of your home station? A half wavelength dipole fed with coax is the simplest antenna, but the coax fed dipole is a single band antenna. - there are ways of using it on multiple bands - traps, or extra half wavelength wires for the other bands spaced away from each other - use a 1:1 balun at the antenna feedpoint. Alternately, you can feed the dipole (single wire cut for the lowest band) with ladder line and use a balun in the shack to convert to an unbalanced line and connect it to the KX1 with a short length of coax. - you will need a BNC connector at the KX1 end. The KX1 autotuner does not have a lot of range on 80 meters, so get the antenna plus feedline as close to 50 ohms resistive on 80 meters as you can. If you use a 135 foot wire and feed it in the center with a length of 450 ohm ladder line that is 122 feet long (an electrical half wavelength), you will come pretty close to a 50 ohm load at the shack end of the feedline, and the tuner should handle it on the other bands. If you want additional information about antennas and transmission lines, I would refer you to the ARRL Handbook (every ham should have a copy). You may also find the Antennas, Transmission lines, and Tuners article on my website www.w3fpr.com informative. Yes, build your own antenna, it is a lot of fun to experiment with antennas, and it is much less expensive than the prices charged for pre-built antennas. Some even tout very impressive specs, but that is a stretch of someone's imagination, the basic laws of physics must apply, and some of the ads stretch that truth. (Rant off now!). 73, Don W3FPR Edward Doyle wrote: > Howdy, > > I am new to amateur radio and just upgraded to General a few months > ago and have some basic questions on a power supply for the KX1 and > how to make a wire antenna. I am going to add the auto tuner and the > optional 80 and 30 meter board later. So as far as a power supply can > I use an old AC adapter as long as it is within 8 to 14 VDC and if so > how should it be connected to the connector for J1. Or would a > commercial type application be a better choice. As far as the antenna > is concerned what type of wire should be used and how is connected to > the connector. I hope that as I start building my kit that these > answers will be a little more obvious but I am trying to get as much > information as I can before I start building. > > Thanks, > > Ed > KE7HGA > > _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
