Dear ELECRAFT members... I am working on my TECH W CODE...later GENERAL...I was thinking of going 10 meters/w QRP...due to limited space and yard...plus nosy neighbors....
my family will be working on theirs later for TECH W/CODE...I am using Farnsworth for my CODE..at 5 WPM...for some time I was hitting the CODE wall....as well get into contests and so on...I am planning to buy a K2 ELECRAFT...what would you recommend...tips and ideas....thanks... -------------------------------------------------------------- Hello Jerry, Sandy or both: Unless you live in a metropolitan area with lots of 10 meter activity and you're happy with only local contacts, I think you'll be disappointed in 10 meters. It is on the lower edge of the VHF region and only sees typical shortwave "skip" propagation during the more active years of each sunspot cycle. We are approaching a minimum sunspot period in which for the next several years openings to make contacts on 10 meters more than a few miles away will become quite rare. I'd recommend 40 meters as your beginning band, in spite of severe space restrictions. It's usually "open" to somewhere at all hours and has a lot of activity. If you can put up a wire at least 33 feet long and feed it at the center with open wire line, it'll work very well on 40, 30, 20, 18, 15, 12 and 10 meters. Even at sunspot minimums, you will occasionally find the bands above 40 meters open to DX. Get a KAT2 or KAT100 ATU with that K2 (depending upon whether you're getting a K2 or K2/100) and an Elecraft BL2 balun to make the transition from the open wire line to the output of your ATU at the rig. The BL2 is especially nice because if the impedance at the end of your feeders is something the ATU has a problem with on some bands, switching between 1:1 and 4:1 with the toggle on the BL2 will usually fix that with little fuss. Now, 33 feet for a wire is short for a 40 meter doublet. The ideal length is 66 feet or more. If you can make the wire longer, do so, but a 33 ft wire will radiate only about 1 dB less than a full-size antenna! 1 dB is simply too small for the other station to detect in virtually any situation. So do not pass up the doublet idea simply because you can't put up a lot of wire. I've used antennas like that in my attic when I could absolutely not have an outdoor wire, but it's always best to get the antenna outside, even if it's only a few inches above your roof line. You can bend it as needed to fit the space and supports. Try to do as much of the bending out near the ends as possible, and if you must bend it, keep the angle of the bend greater than 90 degrees. Other than that, whatever you can fit in will get a signal out! The center fed antenna has the advantage that its performance is not dependent upon a good RF ground. A good RF ground is sort of the "Holy Grail" of radio antennas. Countless hours of experimentation and probably millions of miles of copper wire have been dedicated to getting the best RF ground possible, strung out in various ways. That can be an interesting pursuit all its own, but if getting the most RF into the sky with the least hassle is your goal, I strongly recommend staying with the center-fed wire or "doublet" as it's usually called. If running some open wire line (or as a second-best feeder some "ladder line" that looks like huge TV twinlead) is simply not something you can do, try an end-fed wire of whatever length you can get up. At least 33 feet for 40 meters, and longer is always better. In that case you'll need to arrange an RF ground for your rig. Probably the easiest such "ground" that will work fairly well is a wire 1/4 wavelength long. That's 33 feet on 40, 16 feet on 20 meters, and so on. You don't need the ground wire up high. Indeed, it can be run along the baseboard in the house, but the far end must be insulated and kept away from people and pets. It can produce a nasty RF burn if someone touches it while you're transmitting. It won't produce a shock, but it might cause a very painful burn to the skin that takes a long time to heal. I'd recommend an end fed wire over a coax-fed doublet of some odd length. Coax works well when hooked to a center fed 1/2 wave long "dipole", but when the antenna is not 1/2 wavelength long the coax feedline will be subjected to a very high SWR. Coax lines become very lossy at high SWR's. Open wire lines are quite efficient, even at high SWR. That's why they are recommended for doublet antennas. And resign yourself to this truth. In fact, learn to enjoy this simple issue: As long as you are a Ham, you'll always be thinking about a better antenna. There's never yet been antenna so good that another one might not be better. So don't get paralyzed because you can't do what seems "ideal". Start with what you can and work from there. Ron AC7AC _______________________________________________ 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
