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Recent content by The DB

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    Question

    Yes and no. Lets start with the no. It is common knowledge that if the load does not match the impedance of the feed line, then as you travel up said feed line X and R will change. Where a lot of people go wrong is they assume that just because X and R are changing along the length of the...
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    Base Signal Engineering DPX-2000A

    Loading coils are one way of matching said antenna, but not the only way. Any form of impedance matching that can convert the feed point impedance of said antenna to a 50 ohm resonant load will work to match said antenna. In the case of this antenna, a loading coil is just one way to...
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    Mobile Best Mobile antenna coil position

    The logic I've never seen anyone use is the logic based on DC resistance. You seemed to think that all of my argument was based on materials, yet you actually missed the important part. Strangely my statements on materials was more of a side story yet you seem to think it is the end all and...
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    Mobile Best Mobile antenna coil position

    I see your logic now. Its a different way of looking at it than I have ever seen anyone use before... When working with DC, what you are saying makes perfect sense. Further, to some degree, some of that actually translates to what is happening on the antenna itself, even though the signal...
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    Mobile Best Mobile antenna coil position

    The context of my post was clear, I was referring to 1/4 wavelength antennas, not shortened antennas. When you take a full length 1/4 wavelength antenna of a given diameter, and compare it with a full length 1/4 wavelength of another diameter, the wider diameter full length 1/4 wavelength...
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    Mobile Best Mobile antenna coil position

    The problem with both claiming it is "more efficient" while at the same time having a "broader bandwidth" is larger diameter antennas gain their additional bandwidth by sacrificing efficiency. In this case you simply can't have both at once. Its simply the nature of how said antennas work...
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    Base Workman M400 Starduster

    As this is a direct feed design that does not require a special matching circuit, this antenna should be able to handle whatever the components of the antenna system itself can handle. The biggest weakness when it comes to power handling is likely either the coax feeding it or the connector...
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    102" whip vs the rest

    Good article, but there is nothing in it that hasn't been discussed and modeled by Marconi and I on this forum at CB frequencies in the past. The DB
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    Mobile 102 Inch Whip w/spring

    For one, magnet mounts use capacitive coupling, which means there is a space between the magnet and the metal it is "attached" to, effectively creating a capacitor, which means when there is enough power, just like a capacitor, there will be arcs through the dielectric (i.e. your car's paint)...
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    Mobile Best Mobile antenna coil position

    What you are saying is technically true, however unless the antenna is really short (i.e. noticeably less than 4 foot long) you won't notice the difference in performance based on where the load happens to be. A word of warning. In this hobby the words "more efficient" tends to mostly be used...
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    Base New Imax wont tune 11m....this sucks

    No I haven't seen that,thanks for posting it. Back in 2016 I modeled this antenna with the capacitor, unfortunately those models were lost. I recently found some of the models working with this concept and posted them here. I want to do more testing but with my work schedule lately and the...
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    New Sirio 5000 performer

    If you have the most common version that requires an SO-239 mount... https://www.sirio.store/index.php?main_page=product_info&cPath=2_88&products_id=397 Here is an Amazon link to the mount by it self. ... or not, the forum is trying to insert an amazon link as a media file??? Odd. Anyway...
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    Vertical coaxial antenna build.

    A few things. I wouldn't call it a "bazooka" antenna, although I can see some physical similarities in said design, electrically it is not the same. It looks more like a sleeve dipole to me. I don't know why they are using the antenna's velocity factor for an external dimension. The coax's...
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    Unusual Antenna performance

    Its best to use a balun, but you can go straight from one to the other like AudioShockwav shows. You can also get antenna tuners that have said balun and parallel feedlline outputs built in, and their are also link-coupled antenna tuners as well. Its actually primarily the domain of hobbyists...
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    Unusual Antenna performance

    Twinlead, which has two wires held apart by a solid piece of material, no openings. Window Line, which is basically Twinlead with openings in said material. And Ladder Line, which as stated above looks like a ladder. In the past, these were seen as three very different things, but today...