004: 7/10/28MHz “VCH-antenna” and antenna couplers for QRP


I made this antenna according to the JP6VCH article of JA-CQ magazine, and the 7MHz performance is much better than expected. I have contacted many north American stations with my QRPP (0.1w to 0.5W) rig and this VCH antenna combination in Hachinohe of JA7. It just becomes a 28MHz vertical DP of a half wavelength if the coil is short- circuited (bypassed). Therefore, if the L-match type of coupler is used, it’s easy to get a good VSWR. In the case of 10MHz, after you found the resonance point on the coil, the impedance matching is easy with the CLC type of antenna coupler. If the condition goes up, each band is good comfortably at QSO with the whole area of Japan-domestic with 0.5W CW. It is suitable for climbing and hiking because it is made only of a wire and a light weight coil. And, it became a portable antenna that is not able to be parted with. (I made it in 2010)



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