Fishing Rod Vertical

Discussion in 'QRP Corner' started by KC8VWM, Jun 5, 2017.

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  1. KC8VWM

    KC8VWM Ham Member QRZ Page

    Just discovered if I bypass the inductor (attach the red and blue coil tap wires together) and use one of the radials and attach it to the top of the antenna, and run the attached wire like an inverted L, then it does 40m. It exhibited a perfect swr on 7.250 and around 2.0:1 on the lower portion of the 40m band.

    I think I can also make it work like a 2m 5/8 wave vertical antenna too. It involves the idea of only deploying 4' of the telescoping antenna element and utilizing the existing inductor coil as a matching system.

    That will give me 2m through 40m band coverage using a single portable antenna.
     
    Last edited: Jun 14, 2017
    KJ4VTH likes this.
  2. KC8VWM

    KC8VWM Ham Member QRZ Page

    Sets up and deploys very quickly....



    0.8 lb. antenna stores easily inside a go box.

    IMAG0574.jpg
     
    Last edited: Dec 3, 2017
    K7WFM likes this.
  3. K3RW

    K3RW Ham Member QRZ Page

    Is it possible to set up the antenna to where there would be no need for a tuner?

    This is a great antenna for SOTA or the beach!
     
  4. KC8VWM

    KC8VWM Ham Member QRZ Page

    Yup, no need for a tuner.

    All the tuning is quickly achieved with the antenna, so an antenna tuner is one extra piece of equipment you don't need to carry.
     
    K3RW likes this.
  5. K8TDN

    K8TDN Subscriber QRZ Page

    Why can't I see the pictures
     
    KC8VWM likes this.
  6. KC8VWM

    KC8VWM Ham Member QRZ Page

  7. KC8VWM

    KC8VWM Ham Member QRZ Page

    Ok, I fixed the missing photo problem... :)
     
    Last edited: Dec 3, 2017
    KJ4VTH likes this.
  8. KC8VWM

    KC8VWM Ham Member QRZ Page

    Feed point connection and antenna tuning details...

    Tuning the coil depends on your particular fishing pole length and other factors. It is primarily done by experimenting with tapping different locations on the coil. When you find the sweet spot on the coil for the desired band, achieving the best SWR, then mark it with a paint marker.

    The red wire is attached to the telescopic fishing pole side using a hose clamp.

    The wire chosen for the tap should be "rubbery and very flexible." Avoid using stiff wire for your coil taps. The length of the wire should be long enough to reach the entire length of the coil.

    Solder the blue wire to the center pin of the SO-239 connector. I am using a curved blade connector from an Anderson power pole as a coil tap, but you may decide if an alligator clip would work better.

    IMAG0451_zpst0a453pk.jpg

    Wire radials attach to the wing nut. The bottom of the coil attaches to the SO-239 connector. The top of the coil does not connect to anything.

    SO-239 connected to hose clamp using aluminum L bracket.

    There is a small piece of aluminum which is bent into an L shape. It is screwed directly to the S0-239 connector and then the other side of the L bracket is placed under the hose clamp as shown in the photo. This holds the SO-239 connector quite securely in place.

    IMAG0450_zpsoq4y4iad.jpg
     
    Last edited: Dec 3, 2017
    K7WFM and WN1MB like this.
  9. KC8VWM

    KC8VWM Ham Member QRZ Page

    Setup on the deck railing exactly as shown in the photo.

    You know it must be a good antenna, when the very first contact you make with it is a station located in New Zealand. :)

    0413 14246.5 USB KC8VWM 59 ZL4IR 57 ED

    We actually had a 1-2 minute QSO and I was describing this antenna I was using to him.

    Thanks for the 5/7 signal report Ed!

    IMAG0473.jpg

    Later, I was hearing station VK3CM in Australia on 14.214 very well as you can hear in the video recording below.

     
    Last edited: Dec 3, 2017
  10. KC8VWM

    KC8VWM Ham Member QRZ Page

    Approximate tap locations on the coil for different bands.

    IMAG0671.jpg

    Operation:

    For 2m operation the antenna element is telescoped to 4' (5/8 wave long) and the coil is used as a matching network for the antenna. The antenna taps are movable to achieve the best SWR reading.

    On 6m the antenna element can be extended to either 5/8 wave long ( and the coil is tapped and used as a matching network.) or used as a simple 1/4 wave vertical. (54 inches)

    On 10 meters the coil is entirely bypassed by joining the red and blue wires together and this provides a less than 1.5:1 SWR on 10m.

    For operation on 12, 15,17,20 and 30m you tap the coil at various locations marked on the coil:

    The blue wire remains at the same location for all bands "0" but it remains adjustable if desired. This antenna is a DC grounded design.

    The red wire taps the yellow paint mark locations on the coil to work other bands down to 30m.

    On 40m you tap the coil at "40 / 12" and attach one of the radial wires approx. 20 ft. long to the top of the antenna extending it in an inverted L configuration away from the top of the antenna. This provides an SWR of 1.2:1 on 7.200 and 2:1 at 7.050.
     
    Last edited: Dec 3, 2017
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