Saturday, November 28, 2015

Cold enough for antenna work

My last big project before winter was getting a wire antenna up for 160m. My HF antenna has been a Carolina Windom up 40' or so, hung below the trees. It has been a fabulous antenna for me, allowing contacts all around the world. But lo, it does not work well down at 160m. The HF gurus in my area continued to remind me that I needed to get down on 160...so that project finally bubbled to the top of the list. I would have a two HF antenna QTH!

My first try was an end-fed zepp. After some reading and encouragement from others, up went the wire. I placed 500' of 12AWG up in the trees. This time instead of hanging it below the trees, I used the bow to shoot it right over the tops. My youngest daughter and I had a blast over the week doing the project, including making some homebrew ladder line to feed it. After about two weeks of working on and off on it, the time to test had come. The results were awful. Although it tuned up ok, I swear it generated noise. I heard birdies I've never heard before, but the signals I wanted to hear were 3 S units or lower than the same signals on my Windom. I tried different grounding solutions, and even tried re-orienting the end of the wire to make more of a loop. I added a 1:1 balun (based on some other reading) but that solved nothing.

Not every experiment results in success, so down came the wire. Funny, it took about 10 minutes to pull it all down compared to the week to get it up. Anyway, Fred KC9REG had given me a commercially made 160m double bazooka that I had stashed away in my barn. I pulled it out, laid it on the ground, and determined which tree limbs I could hang it from. No more laying wire in the trees - this one was going up in the clear. After about 3 hours of work (I must be getting better) the antenna was in the rainy 37F air.

I took the KX3 outside under a tree and hooked up the coax (no ladder line this time). While it tuned ok, there seemed to be no signals anywhere. A check of the KX3 on the Windom revealed that the Apocalypse had not occurred. Ugh. Will I ever get a working 160m antenna?

I texted Fred (I was so sick of ham radio by this point that I reverted to the phone). He assured me the antenna had worked the last time he had it up. We texted back and forth a few times, and then he called. He offered to bring up his analyzer to see what was going on. About an hour later Fred shows up and sees something very interesting...the antenna isn't resonant on any frequency. We checked the PL259 at the ground and it was fine. We let down the apex and plugged his analyzer right into the antenna. It looked good, but the PL259 at that end of the coax was loose. Not just loose, it spun. It was held on by shrink wrap. This was a commercially made coax I had never used before. I won't name names, but don't trust fly by night ham radio stores that have nothing more than a website and a guy named Bruno making stuff in the back of a warehouse.

I drug the ends of the coax into the porch, and Fred pulled out his soldering gun(yep, he brought everything with him.) Fred had me back in business in about 5 minutes. Back out to the antenna, pulled it up, hooked up the analyzer and wow...it worked! Pulled out the KX3 and I had signals all over the place.

Finally, after an expensive long wire antenna building experience (just under $100 in raw supplies) an elmer named Fred came through with both an antenna, soldering gun, and knowledge to make it all work. Watch out 160m...here I come!

2 comments:

Richard Carpenter said...

My 80 windom will tune up on 160. Maybe we can sked a CW qso.
Richard N4PBQ

Michael Brown said...

We definitely should!