Attic Dipole Ladder Line

Ladder line fed dipole in attic some local qrp folks known as the knightlites meet regularly on 3 574mhz they meet on 80m so that nearby folks can participate via skywave effect of 80m.

Attic dipole ladder line. Posted by brian duerr wb2jix on 26th oct 2015. Ladder line fed dipoles are ideal for attic use assuming that you can route the ladder line to your radio without too much metal contact. If you don t have any fire breaks within the wall you can cut out a hole in the wall run the ladder line down inside the wall from the attic and install a plastic bracket and plastic blank outlet cover with binding posts for the ladder line connection if you wish. Don t worry about the length of your antenna.

The infamous attic dipole. 8 ft in the attic is plenty height for a good mobile screwdriver and if you have room for a dipole you should have room to staple down a decent amount of chicken wire for a counterpoise. Paint or tape the white ladder line to coax transition fitting use cameo dacron for supports color white insulators tie supports to trees at least 20 above grounds people can t mess with learned this the hard way. The better your antenna the more success you will have making contacts.

In the case of the ladder line dipole just make it as long as possible and stuff it into your attic any way you can. Use your antenna tuner and determine on which bands you can achieve a 1 1 swr. It s easy to lose 75 of your power in your coax when operating on bands where the non resonant dipole presents a high feedpoint impedance to the feedline. If you run the ladder line through a metal box it will interact in some way.

With ladder line there is very little contact area between the spreaders and the conductors and when the other two type of loss are addressed can be an extremely low loss feed system. If you run an all band dipole with a tuner in the shack you need ladder line. Let your antenna tuner worry about getting the best swr out of this system. Well my 40m windom loads up very poorly on 80m and i m likely burning a good bit of my meager power heating the coax.

This was installed at a previous qth i will be the first or millionth remember i m from fl to affirm that the antenna is the determining factor for success when it comes to one s station set up. If you have an attic for example install the longest dipole you can and feed it with ladder line. Coax is very lossy when operated at high swr. Tie in attic or any available trees at your site.

Mac af4ps fp 51 note.