Home

  About us
  • Our Mission
  • What is VHF+?
  • What do VHF'rs do?

  •   VHF+ Contesting
  • Annual Contests

  • VHF+ ham stations
  • Rovers
  • Fixed Stations

  •   VHFSouth Forum

      Technical Info
      Links

      Site Updates

     
      2, 3 & 4-Port Power Dividers...

    50 Ohm – Power Dividers
    QST October 1973 pg 97

    (with corrections of dimensional errors in original article)

    Mhz

    Dimension A

    Dimension B

    Dimension A

    Dimension B

    144

    41.00"

    42.25"

    1041.4mm

    1073.2mm

    220

    26.84"

    28.09"

    681.7mm

    713.5mm

    432

    13.67"

    14.92"

    347.2mm

    379.0mm

    902/903

    6.54"

    7.79"

    166.1mm

    197.9mm

    1296

    4.55"

    5.80"

    115.6mm

    147.3mm

    2304

    2.56"

    3.81"

    65.0mm

    96.8mm

    Described here and in the accompanying drawings are two- and four-port power dividers for 144-, 220-, and 432-Mhz bands designed by Don Hilliard, W0EYE.  Don stresses that the design information should be exactly followed to prevent performance degrading.  The two-port model uses a 1 inch square, 1/8 inch thick aluminum outer conductor and a 1/4 inch diameter round brass or copper tube for the inner conductor.  The four-port model uses the same outer conductor as the two-port model, but the inner conductor uses a brass or copper round tube, 11/32 inch O.D.  All connectors are UG56A/U mounted in 5/8 inch holes with No. 4-40 screws, 1/4 inch long.  Mounting screw holes are drilled with a No. 43 drill,  taped for the 4-40 thread.  The ends and solder access holes should be covered with 1 x 1 x 1/32 inch aluminum plates held in place with RTV sealant after assembly is completed.  ( I used JB WELD as a sealant, W7CQ )

    The rf handling capacity of the power divider is limited by the type - N connectors, but nevertheless is in excess of the legal amateur limits, being two kilowatts or better at 432 MHz.

    Bandwidth of the devices is more than sufficient to cover the entire band of the design with less than 1.24 : 1 VSWR from QST -  October 1973  page 97

    If you drill a hole through one side of the brass 1/4 center conductor,  the N connector shown below with a #14 copper wire extension will center the tube inside the 1 inch square outer conductor.  This makes soldering the center connector much easier.    W7CQ

    2-port connector

    Sometimes it is useful to have a three port splitter, like when putting up a 6-yagi antenna array. Using the sams techniques described above, one might construct a spliter according to the drawing below:

    3-way splitter