Transcript Slide 1
1
160 METER BEVERAGE ANTENNA
SEPTEMBER 2007 UPDATED 12/08
K1FTK / KA1SJV ST. AGATHA, MAINE
PRESS ‘ESC’ TO EXIT SHOW
HAVING PREVIOUSLY INSTALLED A 60’ TALL 160 METER VERTICAL ANTENNA AT OUR QTH, WE DECIDED TO ADD A BEVERAGE ANTENNA TO INCREASE OUR STATIONS DX CAPABILITIES. ITS LENGTH, ~1
(589’ ) OUR BIGGEST CHALLENGE : “WHERE TO PUT IT” OUR PROPERTY IS ONLY 160’ WIDE x 200’ DEEP. WE WERE FORTUNATE THAT THERE IS A LARGE FIELD ALONG SIDE OF AND BEHIND OUR PROPERTY. WE RECEIVED PERMISSION FROM THE OWNER TO USE THE FIELD DURING THE WINTER MONTHS.
OUR NEXT CHALLENGE : “ PORTABILITY “ BECAUSE THE FIELD IS CUT AND BALED, WE HAD TO DESIGN A “ SOMEWHAT “ PORTABLE ANTENNA SYSTEM THAT COULD BE INSTALLED IN THE LATE FALL AFTER CUTTING, THEN REMOVED AFTER THE SNOW MELTS AND THE MOOSE START MOVING THROUGH IN THE SPRING.
--- A BRIEF HISTORY -- THE MAINE CONNECTION DR. HAROLD BEVERAGE, BORN ON THE ISLAND OF NORTH HAVEN, ME IN 1893, WAS A 1915 GRADUATE FROM THE UNIVERSITY OF MAINE. HE RECEIVED THE HONORARY DEGREE OF DOCTOR OF ENGINEERING FROM THE UNIVERSITY OF MAINE IN 1938. DR. BEVERAGE DIED IN JAN, 1993. HE WAS 99.
HIS FIRST ANTENNAS CONSISTED OF TWO MILES OF INSULATED WIRE ON THE GROUND AT SCHENECTADY, NY AS AN EXPERIMENT ASSOCIATED WITH THE ALEXANDERSON BARRAGE RECEIVING SYSTEM (USN). IN 1918 THE NAVY REQUESTED THAT IT BE SET UP AT OTTER CLIFFS ON MT. DESERT ISLAND NEAR THEIR BAR HARBOR, MAINE RECEIVING STATION.
ANOTHER ANTENNA INSTALLATION IN HOULTON, MAINE WAS ASSOCIATED WITH LONGWAVE RADIOTELEPHONY, IT WAS AN ARRAY OF BEVERAGES FOR AT&T, AND ACTIVATED IN THE MID 20’s .
THERE WERE MANY MORE OF HIS ANTENNAS INSTALLED ON LONG ISLAND NY, AT RIVERHEAD AND ROCKY POINT AS WELL AS MANY OTHER PLACES AND COUNTRIES.
--- BACKGROUND -- FOR YEARS, DX STATIONS HAVE KNOWN THE BENEFITS OF USING THE BEVERAGE ANTENNA. ITS HIGH S/N RATIO ENABLES WEAK SIGNALS TO BE EXTRACTED FROM VERY HIGH ATMOSPHERIC NOISE LEVELS AND HEAVY QRM. IT IS ALSO KNOWN AS A WAVE ANTENNA. THE SIGNAL STRENGTH INCREASES AS THE WAVE FRONT TRAVERSES THE ANTENNAS LENGTH. OPTIMUM PERFORMANCE IS IN POORER LOSSY GROUND CONDITIONS !
EARLY INSTALLATION FROM QST, NOVEMBER 1922 ORIGINALLY DEVELOPED FOR THE MEDIUM AND LOW FREQUENCIES (<~2.00 MHz ), SOME STATIONS HAVE USED IT ON BOTH 80M AND 40M WITH DECENT RESULTS. THE ANTENNAS PERFORMANCE DEPENDS ON THE INCOMING SIGNALS BEING AT A LOW ANGLE AND OF CONSTANT VERTICAL POLARIZATON. THESE SIGNALS ALSO TEND TO FOLLOW THE EARTHS CONTOUR.
REFERENCE: 1
BEVERAGE RECEIVE PATTERNS TYPICAL PATTERN FOR AN UN-TERMINATED BEVERAGE ANTENNA. F/B RATIO OF ~ 3.5dB. FORWARD 3dB BEAMWIDTH IS ~ ±30º.
PATTERNS TAKEN FROM : “CLASSIC BEVERAGE ANTENNA, REVISITED” QST, JANURARY, 1982 TYPICAL PATTERN FOR A TERMINATED BEVERAGE ANTENNA. F/B RATIO OF ~ 18 dB. FORWARD 3dB BEAMWIDTH IS ~ ±30º.
HAVING RECEIVED PERMISSION TO USE THE FIELD, WE DIDN’T THINK IT WAS APPROPRIATE TO INSTALL A GROUND ROD FOR TERMINATION.
OUR ONLY CHOICE WAS TO USE AN UN-TERMINATED BEVERAGE. BEING BI-DIRECTIONAL, THIS STILL GIVES “GOOD” COVERAGE TO THE STATES AND “REASONABLE” COVERAGE TO EUROPE EVEN WITH ~3.5dB F/B LOSS.
N BEVERAGE LAYOUT FEED ANOTHER DESIGN CHALLENGE IS THE SLOPING TERRAIN. A POSSIBLE ADVANTAGE IS THAT WITH THIS SLOPE, THE TAKEOFF ANGLE TO EUROPE WILL BE LOWER HELPING TO OFFSET SOME OF THE F/B LOSS.
~50’ RISE STATES TERRAIN PROFILE EUROPE FEED 589’
TO FEED POINT GENERAL VIEW OF THE ANTENNA RUN THE RED LINE SHOWS THE PATH OF THE BEVERAGE ANTENNA. AT 7’ HIGH, IT RUNS FROM THE FEED POINT, WEST OF OUR PROPERTY LINE, BEHIND THE TITAN DX, AND STRAIGHT UP THE HILL. IT’S TOTAL LENGTH IS 589’
ANTENNA SUPPORTS
CONCRETE DECK BLOCKS WERE CHOSEN FOR EACH SUPPORT BASE.
EACH BLOCK WEIGHS ~55 lbs, HAS AN 11” SQ BASE AND IS DESIGNED TO HOLD A VERTICAL 4”x4” POST. IT ALSO HAS A 1 ¾” HOLE RUNNING DOWN THROUGH IT’S CENTER. THIS HOLE DIAMETER WILL HOLD 1 ½ “ PVC ELECTRICAL CONDUIT SECURELY IN PLACE. A TOTAL OF 10 BLOCKS WITH CONDUIT POSTS ARE USED TO SUPPORT THE ANTENNA.
USING A 1/8” ROUTER BIT, SLOTS WERE CUT INTO THE TOP EDGE OF THE PVC ELECTRICAL CONDUIT TO LOCK THE 14ga WIRE ANTENNA ELEMENT IN PLACE.
K1FK IMPEDANCE MATCHING TRANSFORMER ANT 470
GND T1 J1 75
THE FEEDLINE IS 75
TFC/Amphenol T660 A 75
TO 470
MATCHING TRANSFORMER WOUND ON A BINOCULAR FERRITE CORE PROVIDES THE PROPER MATCH.
--- FEED POINT -- 10ga COPPER GROUND WIRE HERE, AN 18” LONG STEEL POST STAKE HAS BEEN DRIVEN INTO THE GROUND AND A 12” LONG 4”x4” PRESSURE TREATED POST LOCKED IN PLACE, IT ACTS AS INSULATED SUPPORT FOR THE TRANSFORMER AND ANTENNA. DACRON ROPE TIED TO AN EYEBOLT AND THIMBLE PLUS A SERVICE LOOP REMOVES ALL STRAIN FROM THE TRANSFORMER. THE GROUND ROD WAS DRIVEN 7’ DEEP.
“DAY GLOW” PAINT AND FLAGGING TAPE WERE USED FOR ATV / SNOWMOBILE SAFTEY
TYPICAL VIEW BACK DOWN THE SLOPING TERRAIN TYPICAL VIEW OF WIRE PASSING THROUGH EACH POST
FEED
10
th
POST
VIEW FROM 10 th POST, DISTANCE TO FEED IS 589’ , THE VERTICAL RISE IS ~50’ 77lbs OF WEIGHT WERE NEEDED TO KEEP TENSION ON THE WIRE AND KEEP THE 10 th POST IN PLACE.
FIRST RX RESULTS AND IMPRESSIONS
INSTALLATION AND INITIAL TESTING WERE DONE IN MID SEPTEMBER.
CW . . .
160, 80M CW SIGNAL STRENGTHS WERE COMPARED WITH K1FK, ~15 MILES SW, IN REAL TIME. SIGNAL STRENGTHS WERE TYPICALLY WITHIN 1+ S UNIT. SSB . . . UNDER MOST CONDITIONS, NOISE LEVELS WERE TYPICALLY 1-2+ S UNITS LOWER WHILE SOME SIGNAL LEVELS REMAINED THE SAME, OTHERS INCREASED ~1+ S UNIT AS COMPARED TO OUR 60’ VERTICAL. NOTE: 10/25/2007 I DID WORK WP2 AND OZ1 STATIONS ON 160M USING THE BEVERAGE FOR RX. BAND CONDITIONS WERE ABSOLUTLEY TERRIBLE (NOISE AT S9 TO S9+30). THEIR SIGNALS WERE IN AND OUT OF THE NOISE ON OUR VERTICAL. VERY DIFFICULT BUT COPYABLE. BY SWITCHING TO THE BEVERAGE, THE NOISE LEVELS DROPPED AND THE SIGNALS GENERALLY REMAINED ABOVE THE NOISE, MAKING RECEPTION MUCH, MUCH EASIER.
IMPRESSIONS . . .
FURTHER TESTING / OBSERVATIONS WILL BE DONE DURING THE ‘07/’08 160M SEASON. AT THIS POINT, IF YOU HAVE THE ROOM, IT’S WELL WORTH INSTALLING. IT’S RELATIVLY INEXPENSIVE AND SEEMS TO BE A GOOD PERFORMER ON 160M , 80M AND 40M AS WELL.
UPDATE 12/08 … 2008 CQ160 SSB CONTEST RESULTS … THIS ANTENNA WAS USED DURING THE CONTEST WITH EXCELLENT RESULTS. 1 st STATE OF MAINE WITH 21,608 POINTS.
PLACE FOR THE
’73 K1FTK / KA1SJV
PRESS ‘ESC’ TO EXIT SHOW