I tried the 5/8ths wave and couldn’t get it to tune until it was cut down to 1/2 wave!!!
:-/ On Fri, Nov 28, 2025 at 10:29 AM Gary Sitton via BVARC <[email protected]> wrote: > Dan: > I made both a 2 mtr and a 20 mtr version of the flower pot vertical. > There's also a 5/8 wave version using both 50 and 72 ohm coax. > > Gary, K5AMH > > > > On November 28, 2025 9:22:05 AM Daniel Poirot via BVARC <[email protected]> > wrote: > >> Howdy y'all, >> >> Thinking of our new friend Jose and all of the folks with constrained >> spaces, I have just the thing! >> >> The 'flowerpot antenna' is an end-loaded, half-wave vertical. It takes up >> no space at all, may be deployed for use and hidden away after, is easy to >> build, and is cheap! >> >> The parts list is simple: >> 10' or longer 1/2" PVC pipe >> 10' or longer 50 Ohm RG-58 coax patch cable >> electrical tape and box cutter knife. >> >> The antenna itself may be threaded inside the PVC at the end load coil, >> or just taped to the outside, depending on just how stealthy you need to >> be. >> >> The wavelength of 2 meter frequencies is 2 meters. A half wave is 1 >> meter, and a 1/4 wave is 50 cm. Simple math! >> >> A premade coax feedline is a great way to start, as the pesky BNC is >> already fitted. Lop off the end you don't need. >> >> Measure down 1/4 wavelength. almost exactly 50 cm. Longer is better. We >> will tune for length. Cut around the outside and through the braid, and >> strip off 50 cm of the shield braid and the 'outside'. Leave the inner >> insulator for protection from the elements. >> >> Tape the stripped end to the end of the PVC, leaving 3" or so for tuning. >> Tape along the length of the stripped portion and the next 50 cm. Make >> several turns of tape 1 meter down to anchor the antenna part of the coax. >> >> At this point, wrap nine (9) turns of coax tightly for the end load. Wrap >> this all in plenty of tape to keep the turns from separating. Add several >> turns of tape at the end of the coil to anchor the coil. >> >> Done. That was easy. It actually took longer to read than it does to >> make. >> >> Using our handy, dandy SWR meter, tune the stripped portion to length. >> Mine ended up shorter than 50 cm. but with a nice 50 Ohm matching >> resistance. >> >> The 10 feet of PVC makes for a suitable mast, the tail of the coax can >> reach the HT, or you can extend EACH as necessary. >> >> The performance easily beats the antenna shipped with the HT. I hope it >> lights a fire in you to build another antenna! ;-) >> >> For a video of the exercise, see the YouTube: >> https://youtu.be/4EhUau841jk?si=LWWBV8fhqdQ4zYjX >> >> 73, y'all >> Dan KJ5IZK >> >> ________________________________________________ >> Brazos Valley Amateur Radio Club >> >> BVARC mailing list >> [email protected] >> http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org >> Publicly available archives are available here: >> https://www.mail-archive.com/[email protected]/ >> > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > Publicly available archives are available here: > https://www.mail-archive.com/[email protected]/ >
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