Monday, 10 November, 2003

Homebrew antenna

The Kenwood TH-F6A that Debra bought me for my birthday is a wonderful little radio.  I've programmed local repeater frequencies so I can talk to others, the NOAA weather channel (the best weather reports available), and even the Austin airport communication frequencies so I can listen in on them when I'm nearby.  The radio does have one big problem, though:  one of those little "rubber duckie" antennas.  The radio itself can transmit 5 watts, but the antenna limits the transmit range and also the signals the thing can receive.  There are better antennae commercially available, and I'll probably get one eventually, but even those leave something to be desired.  The antenna on a hand-held radio can only be so long before it becomes unwieldy.

One of the guys at the WCARC meeting on Thursday recommended that I build myself a roll-up J-Pole antenna for use around the house.  My construction skills being what they are, I was a bit dubious about my ability to actually build one of these, but I decided to give it a shot.  It took a trip to Radio Shack for parts, and one to the local amateur radio outlet (called "The Candy Store" by the other hams in the group) for a BNC-to-SMA connector.  This evening I sat down with my soldering iron, wire cutters and wire strippers and followed the instructions on the page.  It wasn't pretty, but an hour or so later (most of which time was spent stripping insulation while trying to avoid breaking the wire) it was time to test.

There's a 2 meter repeater in Walburg, 20 or so miles from the house, that I was unable to trip with my radio when standing outside.  I could receive its signals, but it never received my transmissions.  Since that was the first signal I picked up after hooking up my new creation, I waited for a break in the conversation and announced that I was testing a new antenna.  The signal report I got back was "strong, a little scratchy, but quite readable."  The person responding was surprised that I was hitting the repeater so well with only 5 watts using a home-built J-pole antenna strung from the ceiling.  Apparently, others also have had trouble hitting that repeater from my area.  I didn't talk with him long, as I was standing in the middle of the room tethered to the antenna with 6 feet of coax.  I'll have to get an extension for the feed line.  But now I have a good enough antenna so that I can use the radio in the house.

A successful first project is a great motivator.  I've always been leery about any kind of electronics projects because I'm not very familiar with the nuts and bolts, and my soldering technique could use some work.  This antenna is a great first project:  it's easy for even a rank amateur like me to build, and the results are striking.  I'll take the little victories.  I'm considering a copper tube J-Pole to mount on the garage.