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G8MNY > TECH 18.03.05 14:04l 77 Lines 2676 Bytes #999 (0) @ WW
BID : 37350_GB7CIP
Read: GUEST
Subj: 70cm Bowtie Beam
Path: DB0FHN<DB0MRW<DB0WUE<DK0WUE<7M3TJZ<ZL2TZE<GB7PZT<GB7YFS<GB7CIP
Sent: 050318/1103Z @:GB7CIP.#32.GBR.EU #:37350 [Caterham] $:37350_GB7CIP
From: G8MNY@GB7CIP.#32.GBR.EU
To : TECH@WW
GAIN FIG 10 DB
<................. 550MM.................>
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+ + + + + + 550MM
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SIZE OF ELEMENTS(INSIDE) 170_175MM, ELEMENTS MADE FROM 6MM CABLE
REFLECTOR MADE FROM GARDEN MESH (SQUARES NO MORE THAN 15_20MM)
CLOSE UP OF BOWTIE ELEMENTS
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BRADE OF COAX >> << CENTRE OF COAX
THE BOWTIE IS MADE FROM 1 PIECE OF CABLE ( LIKE 2 W'S PUT TOGETHER BUT NOT
JOINED IN THE MIDDLE)
SOLDER COAX TO BOWTIE AS SHOWN IN CLOSE UP
DISTANCE OF BOWTIE FROM REFLECTOR 100MM. MOVE IN AND OUT TO VSWR.
TO SUPPORT BOWTIE USE 19MM PLASTIC OVERFLOW TUBE.
TO FIX ONTO MESH USE A STRAIGHT PLASTIC OVERFLOW TANK FITTING.
YOU CAN ALSO USE A TANK FITTING ON THE BOWTIE END.
CUT A CROSS SHAPE DOWN THE THREADED END AND FIT BOWTIE INTO CUT-OUTS.
FEED THE COAX DOWN PLASTIC OVERFLOW FIX BACK NUT ON THREADED END.
INSERT A PLASTIC WINE CORK INTO END TO STOP FITTING FROM COLLAPSING.
TIGHTEN BACK NUT ONTO BOWTIE.
IF THE BOWTIE SEEMS FLOPPY YOU CAN FIT 2 22MM POLY WASHERS NEXT TO THE
BACK NUT/BOWTIE SANDWICH.
TO WATERPROOF ROUND COAX JOINTS AND PLASTIC FITTING USE SILICON MASTIC.
TO MOUNT THE BOWTIE BEAM I USED A TV U BRACKET. THIS WAS BOLTED TO THE BACK OF
THE REFLECTOR.
DIMENSIONS AND MATERIALS USED
SIZE OF MESH FOR REFLECTOR 550 MM SQUARE
DISTANCE FROM REFLECTOR TO BOWTIE 100 MM APPROX
SIZE OF ELEMENTS(INSIDE MEASUREMENTS) 170 - 175 MM
REFLECTOR GARDEN MESH ( 15-20 MM SQUARES )
2 PLASTIC STRAIGHT TANK CONNECTORS ( LONG THREAD IF POSSIBLE )
PLASTIC OVERFLOW PIPE
PLASTIC WINE CORK
6MM CABLE
SILICON MASTIC
TV U BRACKET
LASTLY HAVE FUN BUILDING THE BOWTIE. I HAVE USED THIS ANTENNA FOR 10 YEARS AND
HAVE WORKED SOME GOOD DX.
IF YOU HAVE ANY PROBLEMS ON BUILDING THE BOWTIE BEAM DROP ME A LINE.
TO ANDY G6OHM @ GB7HOL.22#.GBR.EU E.O.F
Why Don't U send an interesting bul?
73 De John, G8MNY @ GB7CIP
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