G8MNY  > TECH     03.10.22 07:00z 87 Lines 2727 Bytes #199 (0) @ WW
BID : 30777_GB7CIP
Subj: 23cm 10el Yagis for ATV
Path: ED1ZAC<ED1ZAC<GB7CIP
Sent: 221003/0653Z @:GB7CIP.#32.GBR.EURO #:30777 [Caterham Surrey GBR]
From: G8MNY@GB7CIP.#32.GBR.EURO
To  : TECH@WW

Schematic for 1.2 GHz ATV ant
From G3ZJO                                   (new Feb 06 edited G8MNY)

I have great success with the following dimensions which are from an old DOS
yagi design program.

Make the BOOM from double sided PCB 10 - 15mm wide.

Make the elements from brass brazing rod 3mm dia or copper wire.

Make the driven element a folded dipole or use a gamma match.

                    1249MHz    1316MHz
Reflector Length  = 12.20cm    11.57cm
Reflector Spacing =  4.80cm     4.55cm

Driven Element    = 11.40cm    10.81cm

Director1 Spacing =  2.88cm     2.73cm
Director1 Length  = 10.83cm    10.27cm

Dir2      Spacing =  3.34cm     3.17cm
Dir2      Length  = 10.72cm    10.17cm

Dir3      Spacing =  3.88cm     3.68cm
Dir3      Length  = 10.62cm    10.07cm

Dir4      Spacing =  4.50cm     4.26cm
Dir4      Length  = 10.51cm     9.97cm

Dir5      Spacing =  5.22cm     4.95cm
Dir5      Length  = 10.40cm     9.87cm

Dir6      Spacing =  6.05       5.74cm
Dir6      Length  = 10.30cm     9.77cm

Dir7      Spacing =  7.02cm     6.66cm
Dir7      Length  = 10.20cm     9.67cm

Dir8      Spacing =  8.14cm     7.72cm
Dir8      Length  = 10.10cm     9.57cm

Boom Length       = 45.82cm    43.45cm
Gain              = 11.67dBd  11.67dBd
.........................................................................

For Gamma matching drill holes & solder all elememts at center point.

      ref   de   dir1  2    3       4      5      6      7      8
      ------------------------------------------------------------
       o    o     o    o     o      o      o      o      o      o

      ----I--------------------------------------------------------
===feeder=0
          I

    BNC or N socket mounted in a notch in the boom.

Detail of Gamma match
                                               22mm
  Driven ele. -----------------------------I-----------o---------------
                                                       C 5pF var.
                                           o-----------o
    .........................................................................

For Folded dipole notch top of boom & solder center of element, feed at
socket.
       ref   de   dir1  2    3       4      5      6      7      8
       ------o------------------------------------------------------
        o          o    o     o      o      o      o      o      o

       -----I--------------------------------------------------------
====feeder==0o
            I

    BNC or N socket mounted in notch.
........................................................................
73 - Eddie, G3ZJO @ GB7BEN


Why don't U send an interesting bul?

73 de John G8MNY @ GB7CIP


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