1. You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

antenna project pdl-II made into a quagi please help antenna qurus!

Discussion in 'Amateur Radio Antennas' started by sob, May 23, 2012.

  1. appaloosaguy

    appaloosaguy
    Expand Collapse
    New Member

    Joined:
    Jul 9, 2017
    Messages:
    1
    Likes Received:
    0
    I am trying to build a 3 element PDL can you please post the measurements for the wire, linth of the arms and the spacing of the director element?

     

  2. IRock817

    IRock817
    Expand Collapse
    Active Member

    Joined:
    Oct 29, 2011
    Messages:
    168
    Likes Received:
    30
    Top secret! Shhhh
     

    Attached Files:

    tecnicoloco likes this.
  3. theborg

    theborg
    Expand Collapse
    New Member

    Joined:
    Sep 8, 2016
    Messages:
    9
    Likes Received:
    0
    antenna.JPG I know this is a long shot but I wonder if anyone knows what this antenna is. I bought it from an older guy who said it was a Realistic from the 1970s. It has 2 sections, 6 feet each, that screw together.
     
  4. tecnicoloco

    tecnicoloco
    Expand Collapse
    Tweaknician in Training

    Joined:
    Apr 23, 2005
    Messages:
    385
    Likes Received:
    100
    Archer Crossbow sold by Radio Shack back in the early 80's
    Cat. No. 21-967.This is made of light blue fiberglass

    Back to topic
     
  5. tecnicoloco

    tecnicoloco
    Expand Collapse
    Tweaknician in Training

    Joined:
    Apr 23, 2005
    Messages:
    385
    Likes Received:
    100
    Another Top Secret :unsure:
     

    Attached Files:

  6. Marconi

    Marconi
    Expand Collapse
    Usually if I can hear em' I can talk to em'.

    Joined:
    Oct 23, 2005
    Messages:
    5,424
    Likes Received:
    577
    Appaloosaguy, the regular two element PDL shows to have a driven element wire that is 458" inches total length. That is 9'6" inches per 1/4 wave side or 114" inches. For CB this one is a lot longer than 108" or less inches if used in the middle of 11 meters and using thin wire makes it worse. If you are going for 10 meters you'll need to get out your trusty slide rule.o_O

    I don't know for sure what the reflector length is by reading the Manual, but my copy has a hand written note of the cover page with an arrow pointing to the reflector wire along with a note showing 462.5" inches. That is not much difference but this antenna is inductive and along with the orbital matching setup using a gamma match the 458" inches for the driven element may electrically appear much shorter and that will make the reflector bigger as a %.

    The spacing shows 55.125" inches between the center of the hubs. To be clear the spacing is in the manual.

    As a starter I would make the director hub easily adjustable and start with 55" inches just like R to Dr. If you're lucky and are able to get close to a match with your 3 elements...you might do a couple of short spacing adjustments with the director, making it longer and shorter spacing, and see how it effects the match. You will have to be close with the gammas first however, to really tell.

    It might be best to get the two element working first and then install the 3rd element so you might avoid chasing your tail just trying to get close.

    Tuning this one could be a beast having to tune gammas and not being sure about wire lengths and spacing to boot, much less adding another element where everything could change.

    I read an account of one guy building this idea from scratch, and he spent a long time getting it working right.

    Just remember this antenna, with gamma matching is going to be longer than you might expect and for sure if your using standard formulas.

    Good luck and keep us posted,
     

Share This Page