Sufficient Antenna, I Hope

As you remember from my post, Insufficient Antenna, I installed a wire dipole next to my house. Unfortunately, I was not able to get it very high off the ground. With it so low, the antenna was propagating in Near Vertical Incidence Skywave (NVIS). I was only able to get as far away as Japan from Thailand. Hitting North American proved impossible. I couldn’t even make it to Hawai’i!

Obviously, I had to do something better! There is an antenna mast for TV antennas on the back-side (north facing) of my house. The antennas are not used and according to my landlord, not likely to ever be used again since everyone now uses satellite TV around here. Therefore, she gave me permission to take down the TV antennas and put up a tubular dipole.

I didn’t ask about putting up anything large because I don’t believe the antenna mast is structurally capable of supporting anything more than a few pounds. Keep in mind I’m a structural engineer with a Professional Engineer (PE) license.

On my last trip back to Bangkok, I bought a used tri-band dipole from John HS1CHB. It’s designed to operate on 20/15/10m. Tonight, I assembled the antenna in the dark in my car port in front of my house. I simply balanced the antenna on my fence to get it about 5 feet off the ground in hopes of getting a fairly close SWR reading. I needed to tune the antenna length, or so I thought. Take a look at my SWR vs. Frequency graphs for those three bands!

20/15/10m Dipole Test - 10m

20/15/10m Dipole Test - 15m

20/15/10m Dipole Test - 20m

I can not wait until daylight tomorrow! It’s going to be very difficult getting to the antenna mast. Even more difficult getting it back in the air once I have the dipole mounted. But with results like this, the motivation is there! Wish me luck. I hope to hear you on the air soon!

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