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NZ5N
Bill Dzurilla
Extra Class
NZ5N United States

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Other Callsigns
WN2YRD in 1967 in New Jersey, then WB2YRD. Moved to Florida in 1969, call WB4RSF. Moved to Louisiana and became WD5HRO, then KF5DD, then NZ5N. Retained NZ5N after returning to Florida in 2004. Summer call OM9ACA, Slovakia. DXpedition calls C91NZ, HQ8R



My Ham Radio Interests
DX, EME, VHF/UHF in general, satellites.

Equipment
Transceivers:
ICOM IC-756 Pro II for HF and 6 meters
ICOM IC-7000 for satellites and local repeaters
Yaesu FT-847 for EME, meteor scatter, satellites, 2 meters and 70 cm terrestrial

Amps:
ACOM 2000 1.5kw for HF
Lunar Link LA-200 1.5kw for 2 meters

Antennas:
MFJ 1793 vertical for HF (modified to add 17m, 15m, 10m)
M2 2M9SSB 9 element yagi for 2 meters
Elk 2m/70m dual band log periodic for satellites
Homebrew 12 element yagi for 70 cm (K1FO design)

Other:
KL6M mast-mounted preamp for 2 meters
ARR mast-mounted preamp for 70 cm
Dell Optiplex desktop computer for WSJT and other digital modes
Donner interface

Other Interests
Golf
Star Trek

Clubs
South Florida DX Association

Working Moonbounce (EME) With a Single 9 Element Yagi

From NZ5N

5/26/2010 11:28:29 AM (0 comments) Add a commentAdd Comment


This past weekend was the Italian EME contest, and it was nice to see so many stations active. Not nearly as much activity as for the ARRL contest, but still fun.

It has been really satisfying for me to work EME from my present QTH in an antenna-restricted community. I have a 9 element yagi, an M2 2M9SSB, on a push-up pole. I only raise up the pole when it is dark, or for a short time during the day when there's a station on that I really want badly. Thanks to Joe K1JT's great WSJT software (free), the one impossible dream of working moonbounce is now possible for smaller stations like mine.

I had not known it was possible to work EME with anything less than a giant antenna and a kilowatt of output power. I had been working meteor scatter via WSJT, and a couple of fellows in the Ping Jockeys chat room mentioned they had been able to work some of the Russian super-stations via EME with a small antenna and just a brick amp. The idea of working Russia on 2 meters was intriguing.

It is possible to work EME without an elevation rotor for about 90 minutes each day, for 45 minutes after moonrise and 45 minutes before moonrise (when the moon has an elevation of less than about 20 degrees), so my first thought was to give it a try at moonrise without elevation. Most of the current EME activity is in Europe, so from the USA there is far more EME activity at moonrise rather than at moonset (although there are some regulars in Japan who can be worked at moonset).

After corresponding with Paul G4DCV on a different topic, I came across his QRP EME web page at
http://www.g4dcv.co.uk/eme.htm.
His 9 element Tonna seemed comparable to my 9 element M2, and his armstrong rotator seemed easy to build, even for a non-techie like me. So I built something similar, see the photo section for pictures.

Some say that the best time to work EME is at moonrise or moonset, because a horizontally polarized antenna parallel to the ground can provide up to 6 db of "ground gain." However, I have had more success when the moon is at a substantial elevation because, as Paul's page points out, there is less noise and electrical interference when the antenna is pointed at the sky.

My antenna is aimed at the moon strictly by hand. When the moon is visible, I just look from the behind the boom and line it up with the moon as best as I can. When the moon is not visible, I get the moon's azimuth and elevation position from the WSJT program. At first, I used a compass and protractor. but now I pretty much know the direction from memory. Precision is not required in the aiming, you can be 10 degrees off or more (at least with a single yagi) with no significant drop in reception. The antenna should probably be re-aimed to stay pointed at the moon every 20 minutes or so.

My original plan was just to make a few EME contacts to be able to say I had done it. But EME is habit forming, takes you back to the thrill of your first QSOs as a novice. Now I'm just trying to come up with some kind of plan to enable me to put up a bigger antenna, which would dramatically increase the number of stations I can hope to work.

With a single antenna, about the best you can hope for is to work stations that are running a kilowatt or more of power AND have a stack of at least four yagi antennas (in EME parlance, a "4x"). If you have luck and more patience than me, you may also be able to work on occasion a station with less power or with just a stack of two antennas ("2x").

As of today, I have worked 12 countries, with the following stations in my EME log: AA7A, DK1CO, DK3BU, DK3EE, DK3WG, DL8GP, EA5SE, EB5EEO, ES3RF, ES6RQ, HA0HO, HB9Q, I2FAK, IK3MAC, K1JT, K4SV, K6MYC, K9DX, K9MRI, KB8RQ, KC7V, KD3UY, K5QE, OK1UGA, PA0JMV, RA6AX, RA6DA, RK3FG, S52LM, UA3PTW, W0PT, W5UN, W7MEM, WA3BZT, and WQ5S.

My rig is a Yaesu FT-847. I have an SSB SP-2 preamp on the mast. I had been using a Tokyo Hy-Power 500 watt amp but have recently upgraded to a Lunar Link. Output power is not that critical for single-yagi EME, because any station you can copy will probably be able to copy you. A brick amp delivering 160 watts or more will certainly help, but the big guns can work stations running 50 watts or even less.

Hope to see you on the moon!

For further reading about small station EME, see:

* QRP EME, http://hb9q.ch/joomla/index.php?option=com_content&task=view&id=37&Itemid=86

* Get ready for 2m MoonBounce Communications, http://www.vhfdx.net/jt65bintro.html

If you think a 4x antenna system is big, take a look at the 64x antenna of Sam RN6BN: http://www.73.ru/


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