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IZ3LSV

[San Dona' di P. JN]

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G8MNY  > TECH     04.04.19 06:57l 73 Lines 3542 Bytes #999 (0) @ WW
BID : 64605_GB7CIP
Read: GUEST
Subj: 70cm 27el G3JVL's QLY
Path: IZ3LSV<F1OYP<SR1BSZ<GB7CIP
Sent: 190404/0556Z @:GB7CIP.#32.GBR.EURO #:64605 [Caterham Surrey GBR]
From: G8MNY@GB7CIP.#32.GBR.EURO
To  : TECH@WW

By G8MNY                                (Updated Nov 18)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)

This is a large horizontally polarised beam with about 20dBd gain! It came out
best in a club garden range test, compaired with other very long boom yagies &
multibeams.

#  1 2 3 4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
# ()()()() () () () () () () () () () () () () () () () () () () () () () () ()
~~~~~n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The elements are all 1/8" plated steel loops welded to 2BA bolts to the 3
section 32mm dia ally tube boom.

The driven element is braised on to the round N socket (N Barrel?), then it is
dropped onto a large hole in the boom & a screw fixes it some how & the top all
mastic sealed. There is no need for baluns on QLY as the fraction of a degree
off the horizontal due to inbalance is no loss at all! SWR in mine is still a
good 1:1 after many years!

The boom has three 1/8" thick strip tags weld to it, 1.5" tall & 2" wide for
the 2 ends, with the middle one is 3" wide for a 2" U exhaust clamp.

Reflector 2 is large slotted ally plate (less wind loading) welded up from 39cm
wide strips with vertical support strips to make a 36cm tall reflector & it has
a welded on plug that fits the tube for mounting.

Support struts are 2x 1400x 20mm ally tube flattened & drilled at ends for the
2BA bolts to the welded on ally tags & central 2" U exhaust clamp. Needing
55cm of mast for the support struts.

Ref
2     ---------------------------- D i r e c t o r s -----------------------
Ý 1 D 1 2  3  4 5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 29 21 22 23 24 25
Ý ³ ³ ³ ³  ³  ³ ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³
Ý ³ ³ ³ ³  ³  ³ ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³  ³
ßßßßÛßßßßßßßßßßßßßßßßÛßßßßßßßß ßßßßÛÛßßßßßßßßßßßßßÛßßß ßßßßßßßßßßßßßßßßßßßßßß
    N                 ~Ä-.._        u       _..-Ä~
                            ~Ä-.._ u  _..-Ä~
                                  ~ßß~

I had measured my one in case I lost a bit. Here are the measurements, all
elements loops taper down in size, so only some of the loop lengths were
measured.

                From      Loop                           From      Loop
Element        End mm   Length mm        Element        End mm   Length mm
Reflector 2       0      390x360         Director 12     263
Reflector 1      24        730           Director 13     290
Loop Dipole      31        700           Director 14     317
Director 1       40        630           Director 15     344
Director 2       46                      Director 16     371
Director 3       59                      Support Tab     383
Director 4       73                      Director 17     398
Director 5       82                      2nd Joint       408
Director 6      100                      Director 18     425        615
Support Tab     117                      Director 19     452
Director 7      127        625           Director 20     479
Director 8      154                      Director 21     506
Director 9      181                      Director 22     533
1st Joint       195                      Director 23     560
Director 10     208                      Director 24     588
Director 11     235        620           Director 25     615        585
Centre mount    250                      End of boom     617


Why Don't U send an interesting bul?

73 De John, G8MNY @ GB7CIP


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