Tuesday, June 26, 2012

A VHF ANTENNA FOR YOUR APARTMENT

Apartment dwellers face unusual antenna problems, whether they be the  installation of HF antennas or VHF antennas.  Like many of you, I've resorted to using my handheld attached to a mag mount atop a refrigerator or other piece of interior metal.  While this arrangement works, it can be unsightly or even dangerous.

It seems Yvon Laplante, VE2AOW, has come up with an apartment antenna which is not only effective and cheap, but also disguiseable and safe.  Laplante's idea can be found in the "Hints & Kinks" column of "QST" for July 2012.  In Laplante's words, "I made a small dipole antenna using telescoping antennas I took from old, broken FM radios.  The antenna is mounted on a...3 x 5 inch piece of Plexiglas with two suction cups.  With my radio placed close to a window, I attached the antenna to the window and adjusted the two elements for 2 meters--about 19 inches.  The antenna gives very good results."  This antenna has low visibility and can be easily moved to better locations in the apartment. 

This afternoon I tried a similar antenna in the bedroom facing the island of Maui (a repeater there is about 75 miles from my qth.  The repeater is on the slopes of Mt. Haleakela).  Getting 2 meter signals to a local Hilo repeater is quite difficult with several ridges and mountain slopes directly in the path from my qth to Pepeekeo (just outside of Hilo--about 22 miles from my house).  So, most of us along the Hamakua Coast rely on the Maui Island repeaters for coverage.  Anyway, I taped two 18 inch pieces of #22 AWG wire to the bedroom window and fed them with  RG-6 coax via a HI-Que coax connector.  My old Kenwood handheld (TH-21) was able to raise two Maui repeaters with this arrangement.  My usual 2 meter antenna is a Larson 5/8 wave mag mount on the metal roof of my garage.  The Larson provides a better signal, but the "lash-up" I copied from VE2AOW seems to work fairly well.  I'll keep this homebrew antenna as an emergency backup to the Larson on the garage roof.

I have a similar set up in my van.  I placed an 18 inch vertical element and an 18 inch horizontal element fed by RG-6 coax on a window attached to the right sliding door.  I provided some slack so opening the door won't damage the coax.  While this antenna is a compromise, it does serve me well in Hilo town, where I can hit several local repeaters with my Kenwood TH-21 handheld.  I keep this old Kenwood as a spare and as a mobile rig for the van.  Even at the low power setting, I  can get solid copy in and around Hilo.

Aloha es 73 de KH6JRM--BK29jx15