What’s In A Board? Answered September 2017
Old and new versions are usually available at local ham radio gatherings such as a “hamfest” or online at They are currently selling the 23rd edition, but any edition from the last 30 years or so will likely suffice. The source I recommend for anyone learning about antennas is The ARRL Antenna Book. If you want to learn more about circular polarized antennas and have very good simple explanations of what is going on with circular polarization. For weak signals you will need to try both Right Hand and Left Hand circular polarization to determine which is needed, as the wrong circular polarization is worse than just using a linear polarized (in your case vertical) antenna. If you have a receiver capable of covering the 145 MHz and 437 MHz ranges you may want to check out ham radio satellite sources such as for information about receiving them.Īs for receiving circularly polarized signals should you find any, if they are strong enough that the null in signal strength is still strong enough for you to hear it clearly, then you will likely not know the signal is circularly polarized and need do nothing special to receive it. If you do find any of these signals they will have a distinctive rhythmic change in signal strength as the polarization of the signal changes maximum as it matches your receiving antenna’s polarization, then minimum as it becomes opposite your antenna’s polarization. Circular polarization is mostly used for receiving Low Earth Orbiting (LEO) satellites and stuff in the microwave and upper end of the UHF ranges. You are very unlikely to encounter circularly polarized radio signals from local sources.
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