The neighbors sure prefer my new "flagpole" antenna to my other rooftop contraptions! The flag only flies during the summer months, generally from May through October, to avoid pole-snapping winter winds. But the neighbors still seem to appreciate the effort, and even better, I appreciate it: as an antenna it performs really well year-round!
One 10 gauge wire 23.5 feet long was dropped through the PVC pipe and secured near the top with one screw. Since the wire is insulated, it probably appears to be a slightly longer wire to the antenna tuner, which is an Icom AH-4 sitting at foot of the antenna. Notice the counterpoise running from the AH-4 in a circle around the tripod. Run the counterpoise in any direction you want, but make sure it is at least 5% longer than the antenna wire. (The roof shingles include some kind of metal - this helps too!)
The tripod you see above is a heavy-duty Easy-Up purchased from AES, not a lightweight Radio Shack special. Below, notice that although the AH-4 is waterproof, I cover it to keep off the California UV rays:
Schedule 80 gray PVC pipe should be used instead of the standard white pipe. Notice the additional thickness in the gray pipe, which makes it much stronger. It is also more UV resistant; the white pipe is always supposed to be buried. That was a mistake, and I will switch to gray pipe soon:
Results so far in signal gain/loss vs. my old GAP Titan vertical, based on contacts near and far:
- 80 meters up 3 S-units across the band. (Also the GAP is limited to only 100 kHz in this band. The "flagpole" works the whole band.)
- 40 meters up or down 1 S-unit, or no change, depending on which hop. In the end, my dipole beats both verticals on 40.
- 30 meters up 3.5 S-units. (Doesn't need the tuner here.)
- 20 meters up 5 S-units!!!!
- 17 meters up ½ S-unit
- 15 meters up 1.5 S-units
- 12 meters up 1 S-unit
- 10 meters down 1.5 S-units, but less noisy so I can hear more signals.
- Wont tune on 160 this was expected; maybe with a longer wire.
- Wont tune on 6 meters this was not expected. It must be too close to six meter resonance for the longwire tuner to handle (but not close enough to work without the tuner either). This would only be useful for local repeaters anyway, and there is virtually no activity on six meter FM around here. I have a horizontal loop for six meters SSB, and even a forty meter dipole works on six for casual use.
OK, I admit, the GAP Titan was lower to the ground and to the side of the house...
...but the manufacturer makes all sorts of claims indicating this shouldn't matter. Of course it does matter, but I wasn't about to put that monster up on top of my roof. Also, I think in the end the GAP was a rather mediocre antenna. I'll post a review of the GAP soon. It did best on 10 thru 17, and it was a great to have during the sunspot peak.
I sure am happy with my "flagpole" antenna now though! Future plans include replacing the white pipe with gray pipe, and maybe trying a top hat (four 23.5' wires coming off the top at 45 degree angles) to see how that improves performance on the low bands. Stay tuned! In the meantime, I've had a lot of questions about this project, so please see the FAQ page, but feel free to e-mail anytime.
Antenna Tower Project: MA-40 Rotatable Crank-up
Antenna Farm 3: The Slanted Roof Solution
Antenna Farm 2: The Flat Roof Challenge
Flagpole Antenna Project • Antenna Farm 1
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