Bill's- HomeBrewed Pan Cake - 40 Meter TAK-tenna

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KA6KBC, Jun 12, 2008.

Thread Status:
Not open for further replies.
ad: L-HROutlet
ad: l-rl
ad: Subscribe
ad: FBNews-1
ad: Left-2
ad: Left-3
ad: L-MFJ
  1. KA6KBC

    KA6KBC Ham Member QRZ Page

    Homebrew: Tak-tenna or Tak Antenna ?

    Hi All,

    A few months ago I posted a note about my homebrew version of this Antenna - I've done a little better write up that I have posted on my webpage.

    http://billbrwn.tripod.com//id3.html


    73's

    Bill - KA6KBC
     
  2. KE7VZW

    KE7VZW Ham Member QRZ Page

    I have a friend with a taktenna here in chandler; we put a "big #31" choke at the feedpoint (6 passes through the #31 choke for 20 meters). It wouldn't tune anymore with a choke on it. Not sure why that is but the RF was biting on the case edge prior to the choke, so i'm assuming feedline radiation.
     
  3. W8JI

    W8JI Ham Member QRZ Page

    The EH antenna won't work well with a feedline choke either. Neither does the Isotron antenna, or the CFA.

    All of these magical antennas work best when the coax is allowed to radiate and be the antenna.
     
  4. M3KXZ

    M3KXZ Ham Member QRZ Page

    Was it a Taktenna made for 40m? If so then it would be just as hard to match on 20m as a 40m dipole. After all, it's nowt but an extremely shortened dipole with lots of loading by way of spiral capacity hats. If it was one made for 40m that you were trying to load on 20m then you'd be trying to match a very high voltage point.
     
  5. KE4SWA

    KE4SWA Ham Member QRZ Page

    To help with the "biting" try moving the choke away from the feed point toward the transmitter so the feed line can still be part of the antenna. For this type antenna to work the feed line has to be able to radaite.
     
  6. KK4ASS

    KK4ASS QRZ Member

    this will look nice sitting beside my Isotron......
     
  7. KE7VZW

    KE7VZW Ham Member QRZ Page

    Good point.... I misspoke, we were actually working it on 40 around 7.077 where all the hells hang out. Still confuse my bands as a newb from time to time.

    What kind of a takeoff angle do you get from vertical coax that is radiating ? How is the efficacy as a receiving antenna ?


     
    Last edited: Dec 30, 2008
  8. KE7VZW

    KE7VZW Ham Member QRZ Page

    How about directly at the transceiver ?
     
  9. W8JI

    W8JI Ham Member QRZ Page

    With these types of antennas, it is not just the feedline that radiates. It is the feedline, the radio case, the wiring in the shack, the power lines and ground leads into the shack, the telephone wires, and anything else that connects to or gets near the radio case or the feedline.

    If you stop the common mode current, then you are stuck with a tiny antenna and it will work exactly like any tiny antenna with the same loading system.

    It is possible to build a very efficient smaller antenna. With care and planning a pretty small antenna, say one 20 feet long, can be nearly as good as a full size antenna would be at the same height. There would be very little difference. You would have to do it carefully, however.

    73 Tom
     
  10. M3KXZ

    M3KXZ Ham Member QRZ Page

    Wrong. The TakTenna will work as a very short dipole without having to have feedline and associated RF. It just doesn't work very efficiently. It is a VERY short dipole on 40m. Allowing the coax feedline to radiate then the feedline becomes the main radiator and is more efficient at this than the tiny dipole on top of it. But then you have all the problems associated with RF on the feedline and elsewhere.

    If fed with twin line, and with a balun at the rig end, then feedline RF can be got rid of. It might be possible for a 40m TakTenna to then work quite well on the higher bands (say 20 and up) fed with twin lead, and then to work 40 one could short the twin lead at the shack end and feed it as a vertical with a capacity hat (which would be the TakTenna part, with the vertical being the shorted twin lead feeder).
     
Thread Status:
Not open for further replies.

Share This Page