The rules are simple and clear: 1.1. Stations located in overseas and non-contiguous U.S. Territories may be worked by DX stations. This includes Alaska KL7, the Caribbean US possessions KP1-KP5, and
The radiation resistance of your antenna is 12 ohms. The 1.5:1 VSWR tells us the base resistance is either 33 or 75 ohms. The ground loss resistance is either 21 or 63 ohms. The radiation efficiency
Dan, NEC-2 shows a 2:1 VSWR bandwidth of 70 kHz for your antenna and that's with a zero ohm ground. You should be seeing about 90 kHz. You might check it after dark when the AM BC stations reduce pow
The radiation resistance is 25 ohms. I estimate your base referred ground loss resistance to be 10 ohms. So, you should expect a VSWR of 1.4:1 fed directly with 50 ohm coax. To obtain a better match
The simulated radiation resistance is 16 ohms, your GND loss is 9 ohms and efficiency is 64%. No balun is needed. _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? B
No I mean no balun is needed. The coaxial cable external shield current will be roughly that of one radial. With so many radials the shield current will be low. ______________________________________
I had considered this case and it is valid with lossless GND or in free space. But over lossy ground one resonant "radial" with many short radials carries the about the same current. While not entire
Charles, Joe listed some symptoms of excessive feedine common-mode current such as RF bites and RF feedback. If you do not suffer from any of these effects a balun may be of no use. If one does exper
Phil, NEC shows that shortening the radials to 110' will resonate things at 1.8 MHz. The ends are 10' from ground. The radial length can be used to adjust the antenna to resonance. The input impedanc
The paper by Rudy Severns, EXPERIMENTAL DETERMINATION OF GROUND SYSTEM PERFORMANCE FOR HF VERTICALS PART 7 GROUND SYSTEMS WITH MISSING SECTORS is illuminating. _______________________________________
I believe the proposed rule is 2 watts ERP. The typical 70 x 50 foot top band inverted-L can be base loaded on 500 kHz using a 500 kHz inductor. Given an inductor Q of 300 and ground loss of 20 ohms
I beleive there is the issue holding the June Stew on Field Day; there will not be many serious efforts on top band. Do we need four hour top band contests or an occasional QSO party? Something less
To me top band seems to be all about DXing. I can find plenty of if folks calling CQ DX but I don't hear many folks calling just plain CQ. _______________________________________________ UR RST IS ..