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G8MNY > TECH 29.05.12 07:24l 103 Lines 4165 Bytes #999 (0) @ WW
BID : 43068_GB7CIP
Read: GUEST
Subj: 70cm 19el Tonna Yagi info
Path: IZ3LSV<IK2XDE<DB0RES<ON0AR<UA6ADV<GB7CIP
Sent: 120528/2230Z @:GB7CIP.#32.GBR.EU #:43068 [Caterham Surrey GBR] $:43068_GB
From: G8MNY@GB7CIP.#32.GBR.EU
To : TECH@WW
Length Measured
Element in mm Spacing
Reflector 350
Folded Dipole Not done
Director 1 330 Not done
Director 2 315 Not done
Director 3 305 Not done
Director 4 300 Not done
Director 5 297 Not done
Director 6 295 Not done
Director 7 295 Not done
Director 8 290 Not done
Director 9 285 Not done
Centre of boom
Director 10 285 171
Director 11 280 172
Director 12 280 173
Director 13 275 172
Director 14 275 172
Director 15 270 172
Director 16 270 172
Director 17 265 173
Quoted figures
Gain 17dBi
Aperture -3dB H 2x14ø
" V 2x16ø
Front-back 23dB
Side Lobes > 38dB
VSWR ò 1.2
Weight 1.1kg
Length 3.2m
Wind load @ 25m/S 5.4kg
73 de Andy G0FTD @ GB7SXE.#38.GBR.EU
SB TECH @ WW
70cm 27el G3JVL's QLY
By G8MNY (New Jul 10)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)
This is a large horizontally polarised beam with about 20dBd gain! 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?) & the 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 imbalance 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-.._ _..-Ä~
~Ä-.._ _..-Ä~
~ßß~
I had measured my one in case I lost a bit. Here are the measurements, all
elements 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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