Hamstick or base loaded 8' whip?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KK4NSF, Jan 11, 2019.

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  1. N2SUB

    N2SUB Premium Subscriber QRZ Page

    I get the antenna as close to the operating frequency....obviously the lower you go in frequency, the more narrow the band width is, so the band and operating frequency determine whether I use a tuner. For the most part I do just to be on the safe side.

    Regarding the counterpoise, I use a single wire to the ground. The length is determined by the band using this formula: 180/freq in MHz. It's amazing how the counterpoise of the correct length can pull the SWR right down. The length of the counterpoise is not critical, so just get as close as you can....for a portable or semi-permanent setup, I normally just use clip leads clipped together, that way I can change the length by adding/removing a lead. They come in many different lengths:

    https://www.amazon.com/Wobe-Alligat...ents=p_n_feature_eleven_browse-bin:3622112011
     
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  2. VE3CGA

    VE3CGA XML Subscriber QRZ Page

    I used hamsticks and a 8' base loaded whip on my ole villager with a ft757gx. Worked Europe frequently and VK one Feburary almost daily (6am) for about a week. This was back around 1998. Kids were young so their voices came in handy to break through the odd pile-up. Otherwise 40M & 20M were my favorites.
    Had to use a 3' mast to get the antenna up & away from the back hatch. On 80M I had to add some inductance at the base to get a match which had a very narrow bandwidth.
    TxStock34.jpg
    The antenna was directional due to the mounting. Never used them for portable or home.
     
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  3. WB5WPA

    WB5WPA Ham Member QRZ Page

    re: "I've only used a hamstick on the roof of a wagon ... mount bolted to the roof rack."

    This was for 40 meters. It worked - as I've nothing to compare it to I can't say how well it worked, but, it did communicate with a station during the day/afternoon over a several hundred mile path here in Tx.

    The 80m hamstick is another story. And don't even think about using the 80m hamstick via a tuner on 160m, unless you just absolutely need to *receive only* down there ...
     
  4. KC8VWM

    KC8VWM Ham Member QRZ Page

    Knowing how a hamstick is designed and how it actually works, I would prefer using a base loaded whip.

    Basically a hamstick is just a tuned inductor coil and the majority of its radiation is only occurring along a small section of the antenna at the top.

    Everything below the coil at the top, is basically just a wire feeding this coil and it's length can be varied without much change to the short antenna on top.

    In fact, you could cut off the coil at the top of a hamstick and use it as a short antenna by itself. Yup, that's exactly what I did alright. :)

    There wasn't much difference if the coil at the top was cut off and used by itself, or if this coil was connected to a series of spirals leading to the feed point.

    The intended objective of the hamstick or similar designs is to place the "antenna" on top of a fiberglass rod as high as possible above the vehicle and feed it with a piece of wire leading from the feedpoint.

    So yeah, think I would prefer using a base loaded whip because two foot long antennas attached to a fiberglass rod are not particularly efficient regardless what the SWR reading achieved might say. :)
     
    Last edited: Jan 11, 2019
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  5. KC8VWM

    KC8VWM Ham Member QRZ Page

    This was an experiment using a coil cut off the top of a helically wound "Firestick" antenna.

    A telescopic whip was installed on top of this coil and could be adjusted in length to achieve a perfect SWR reading on every band from 10 through 20 meters.

    Adjusting the length of the telescopic section below the coil made no difference whatsoever.

    Removing the telescopic antenna at the top of this coil makes it work and function on 10/11 meters in the exact same way as another identical 5' tall Firestick antenna that wasn't cut up at all which was used for comparison purposes. There was no difference in reception or transmitting performance between these two antennas.

    So what we have here is basically a 1' tall antenna that's designed to work on 10/11m and adding a telescopic rod on top made it capable of being tuned on different HF bands. It's basically a tunable dummy load. :)

    IMAG0951.jpg
     
    Last edited: Jan 11, 2019
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  6. NH7RO

    NH7RO Ham Member QRZ Page

    I have always looked upon hamsticks more as mobile dummy loads than serious mobile antennas, too. Good for you for going to the trouble of actually confirming things in the field, Charles.
     
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  7. WB5WPA

    WB5WPA Ham Member QRZ Page

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  8. W5DXP

    W5DXP Ham Member QRZ Page

    Charles, if you look at the shootout results, you will see that the center loaded antennas have a gain advantage over the base loaded antennas to the tune of about 3 dB, i.e. double the radiated power. That's because most of the radiation comes from the highest current section below the loading coil. It is true that the length of the bottom section doesn't have much effect on the feedpoint impedance or resonant frequency but that is because of a negative phase shift at the bottom of the loading coil. However, the length of the bottom section has a large effect on the radiation resistance and therefore the gain of the antenna - the longer, the better (limited to 1/4WL, of course).
     
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  9. KC8VWM

    KC8VWM Ham Member QRZ Page

    If true, I should have been able to measure it with a F/S meter.

    I admit, my testing conditions were rudimentary and not ideal but I simply couldn't measure any observable differences between the 1' antenna and the 5' antenna as far as the F/S meter was concerned.

    Additionally, in both cases, the largest intensity of RF radiation existed primarily in proximity to this coil and not much anywhere else below the coil.

    I simply did not observe any significant performance differences between the 5' or the 1' antenna.
     
  10. VE3CGA

    VE3CGA XML Subscriber QRZ Page

    I'd agree that the base loaded whip is better. I used a 8' whip with base loaded coil on 80M, it had more bandwidth and (that day) better reports, at least with other VE3's. I used a center loaded 8' whip on 15M and when the band was open it worked pretty good.
    It was an old fire truck vhf vertical dipole so I salvaged the 3/8" dia. bottom mast, made a center loading coil with solid house wire and some pvc with machined ends then one of the hamstick whips on the top.
    the only problem was that on voice peaks it would activate the rear wiper motor - didnt matter the back window was always dirty.
    Last August I had to drive up north in my Sportage, decided to fire up the 757gx and go mobile. I fastened my old villager bumper mast to my bike rack that plugs into the trailer hitch, threw on a 40M hamstick and worked a couple stations while driving north from Barrie up to north bay.
    I didnt tune the hamstick (lots of sw) The antenns base was about 1/2 way up the back of the KIA roughly 4' higher than what it would have been on the villager. Even just listening it sure made the trip seem a whole lot quicker.
     

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