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Beverages and BOGs

Beverages and BOGs. Carl Luetzelschwab K9LA k9la@arrl.net http://k9la.us. 160-Meter DXCC. Received my 5BDXCC in 1987 when we lived in Texas Started on 160-Meter DXCC when we moved back north in 1988 160-Meter DXCC from Indiana seemed easier than 80-Meter DXCC from Texas

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Beverages and BOGs

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  1. Beverages and BOGs Carl Luetzelschwab K9LA k9la@arrl.net http://k9la.us NWIDXC Dec 2016 K9LA

  2. 160-Meter DXCC • Received my 5BDXCC in 1987 when we lived in Texas • Started on 160-Meter DXCC when we moved back north in 1988 • 160-Meter DXCC from Indiana seemed easier than 80-Meter DXCC from Texas • Closer to EU in Indiana • Another hop to EU from Texas • Better transmit antenna in Indiana • Inverted-L with elevated radials vs half-sloper in Texas • Higher power – 1 kW in Indiana vs 400 W in Texas • Quieter location – rural Indiana vs residential Texas NWIDXC Dec 2016 K9LA

  3. My Inverted-L Served Me Well • Achieved DXCC on 160-Meters using the inverted-L for receive • On a typical winter night with the inverted-L, my S-meter hovers around S3 (about -103 dBm) in a 500 Hz bandwidth • But I was not hearing many other countries spotted by others and locals (K9UWA, KR9U, KD9SV) NWIDXC Dec 2016 K9LA

  4. Trials and Tribulations • I tried an EWE (WA2WVL design in QST) oriented towards EU • Hardly ever saw any improvement in signal-to-noise ratio (SNR) • Thus it didn’t stay up long • Tried short Beverages – about 250ft • To the East - showed SNR improvement • To the South – more noise with the Beverage! NWIDXC Dec 2016 K9LA

  5. Put Up the SAL-20 • SAL = Shared Apex Loop • 20 refers to 20ft horizontal base of each of the four triangular loops • 8-directions, 40ft diameter footprint • Control is thru RG-6 coax • Only one line to antenna • SNR improved significantly • I could hear stations that weren’t there on the inverted-L • See the April 2014 QST for my review NWIDXC Dec 2016 K9LA

  6. Tried the KD9SV RBOG • The “R” stands for reversible, which means you can electronically switch it from forward to reverse • 200ft length recommended for 160-Meters • ENE / WSW RBOG – most of the time it gave a better SNR than the SAL-20 • N9FN has NE/SW and NW/SE RBOGS • Uses it on 80m, too, with external preamp • Caution – RF on BOG coax in transmit • May need front-end protection • Caution – proximity to AM broadcast station • May need high pass filter • See the September/October 2015 NCJ for my review NWIDXC Dec 2016 K9LA

  7. Never tried . . . • Pennant • Flag • K9AY • Other variations of small receive antennas • Receive 4-Square • My opinion – if you’re going to put up a 4-Square, make it for transmit, too NWIDXC Dec 2016 K9LA

  8. RDF • Receiving Directivity Factor • Main lobe gain versus average gain at all angles • Allows a theoretical comparison of different antennas • Caution – definition assumes noise arrives from all directions around the compass • But noise is directional in nature • Caution – many people focus on F/B as it’s easy to measure • But I believe RDF trumps F/B unless noise arrives off the back NWIDXC Dec 2016 K9LA

  9. RDF of Various Antennas NWIDXC Dec 2016 K9LA www.k7tjr.com/rx1comparison.htm

  10. Beverage Performance NWIDXC Dec 2016 K9LA

  11. BOG Performance NWIDXC Dec 2016 K9LA

  12. Tips for Beverages and BOGs • 4ft copper ground rods appear to be adequate for my QTH (in other words, my ground parameters) • Your mileage may vary • Might want to try a common-mode choke on the feed line • I see about 4 dB more noise with a 75 ohm resistor terminating the coax at the antenna than with a 75 ohm resistor terminating the input of the preamp in the shack • Noise getting onto the coax • For a BOG installation • Use rake or blower to keep leaves (dry and wet) and dirt and other debris off the wire – don’t let it get buried NWIDXC Dec 2016 K9LA

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