The antenna wire lengths before trimming are 5.5 m between balun and 20m trap, 5.5 m between 20 m trap and 40 m trap and 11 m between the 40 m trap and the end of the antenna. The tuning process is the same as for the 40/80 dipole, excpet the 20 m wires are trimmed first to an SWR of 1.8:1, followed by the 40 m wires then the 80 m wires. An Attic Coaxial-Cable Trap Dipole for 10, 15, 20, 30, 40, and 80 Meters John DeGood, NU3E [email protected] Abstract A coaxial-cable trap dipole antenna installed in the attic provides a surprisingly effective solution to HF operation on the 10, 15, 20, 30, 40, and 80 meter amateur bands at a QTH with restrictive covenants that prohibit outside antennas.
A trapped dipole is a dipole with blocking filters fitted at the operating wavelengths. For example, a 40 and 20 metre trapped dipole would have traps installed at the 20 metre points which would prevent the 14Mhz band, effectively shortening the antenna. Lower frequencies will pass the trap effectively making the antenna bigger. About Trapped dipole for 40-80-160 meters The resource is currently listed in dxzone.com in 5 categories. The main category is Dipole antennas for the 7 MHz band that is about Dipole antenna projects for the 40 meter band. This link is listed in our web site directory since Friday Aug 25 2006, and till today "Trapped dipole for 40-80-160 meters" has been followed for a total of 91427 times.
Ham Radio HF Dipole Antenna suppliers is a curation of 41 resources about, Ni4L ANTENNAS & ELECTRONICS, Antenna Tensioner Vari-Ten, RippleTech Electronics, Tecadi, Sandpiper Aerial Technology LTD. Resources listed under Dipole antenna category belongs to HF main collection, and get reviewed and rated by amateur radio operators. antenna with a little cut and try using my new Trap and Stub Dipole Antennas for Radio Amateurs computer software package.  Figure 1—An improved 80, 40, 17 and 10-meter trap dipole. If any amateur An Improved Multiband Trap Dipole Antenna - Page 6.