WebOct 6, 2024 · A counterpoise is always 1/4 wave length, and you can set-up a pair for each band you have without needing to disconnect any of them between switching HamSticks, since, like a fan dipole, stray currents that want to travel down the coax shield, will get shunted onto the lowest impedance counterpoise wires, which will be the ones that are … WebThe impedance of a half-wave dipole rises as we move the feedpoint off-centre - away from maximum RF current (minimum impedance of 70-72 ohms)... and into increasing RF voltage territory. Manufacturers of off-center-fed dipole antennas choose an offset feedpoint where the theoretical impedance is approximately 300 ohms on the antenna's ...
Best Location for a Hamstick? RadioReference.com Forums
WebDec 30, 2016 · Angles from 30 to 60 degrees provide a good match, with 45 degrees usually being optimum. Of course, you will need to adjust the whip on the hamstick to tune to lowest SWR. My SWR plotted over 17m is shown. Due to the low feedpoint impedance of a shortened antenna, you can expect SWR to run a bit higher than with a full sized version. WebJul 5, 2024 · I guess next step is to check the impedence values at those frequencies. When the nmo30 and hamstick comes in about a week I will have to rerun the sweeps. The 1:1.7 swr I started to think was due to the terrible ground plane interactions. Bending the antenna away from a pillar resulted in an swr that dropped a few hundreths. top grant writing companies
The Off-Center-Fed Dipole (OCFD) - Ham Radio Secrets
WebWhen building Low Band Vertical antennas, or even Inverted-L antennas for 160/80m, you will often find that the feedpoint impedence is much lower than the theoretical value of 36 Ohms. In fact if it is base loaded it may be closer to 10 Ohms. The "the Hairpin Match" is a simple and easy way to fix this problem. I don't like this name, and would prefer to call it … WebAJ1G 2003-03-19; Hamstick Option on 75 For More Bandwidth; Read this thread with great interest. I have had very good luck on 40 and 80 meter CW using Hamstick type clones using a 500 pf shunt capacitor across the feed point for impedance matching, and using a stinger section made from the 1/8 " diameter stainless steel whip sold by Radio Shack as … WebAs a result, the coil losses are great enough, that impedance matching isn't necessary in most cases. When it is, the amount of reactance required will be vastly different than that required for an 80 through 10 meter … pictures of 420 day