TopBand: 160 meter operation from Rodrigues Island, 3B9

Garry & Yelena
Wed, 24 Mar 1999 00:27:28 -0800

Topband colleagues,

I have received emails and letters from some of the big-gun brethren
soliciting assurances of special attention during our upcoming
DXpedition to Rodrigues Island. As we are aware of what we are taking
on, assurances have not been given. As one of the lowband operators,
I'll offer a few additional comments about prospects for a QSO on 160.

The island is hilly. No one spot offers good coverage to the whole
world, and we plan multiple sites to deal with this. We have two big
Titanex verticals that will primarily serve 80 and 160 meters. I plan to
bring "makings" for several Beverages, and we hope to be on 80 and 160
every night, all night. Having said that, a wise man knows that there
will undoubtedly be contingencies. It rains a lot on Rodrigues, and a
hurricane went through Mauritius and Rodrigues just a few weeks ago. And
we certainly shall not operate through thunderstorms!

I expect high QRN levels. Worse, the geomagnetic disturbances earlier
this month are likely to repeat right in the middle of our operating
period. Such disturbances are much more likely during equinox periods
than at solstices, as the populated regions face right into the solar
wind. The only way to deal with this is for the operators to be
constantly looking for good conditions and exceptional openings, and we
expect to do this as a matter of course.

The geography clearly favors Europe, JA and the Indian Ocean basin.
Propagation to the East Coast of North America should be difficult but
possible; the further east on the NA continent one is located, the
better, as paths then avoid the auroral zone. We will listen hard as we
approach our sunrise. We ask Europeans and others to respect our calls
for North America at those times. We will not reward rude behavior from

Unfortunately, geography and season both conspire against the West Coast
of North America, and no one is more disappointed about that than the
team, four of whom are from the West Coast. There is an area in western
North America which has no darkness path at all to 3B9. Similar
situations were described in articles and elsewhere re Heard Island and
Auckland and Campbell Islands by Bob Brown, NM7M. The "dead zone" is
defined by the sunrise and sunset terminators from 3B9, which, if
extended, cross at the antipode, located west of Mexico. The thin wedge
north of the antipode is the affected area. The amount of mutual
darkness increases from zero the further one's location from the dead

For topbanders on the west coast, the western dead zone boundary goes
northward from Los Angeles, and contacts from LA and San Diego are
highly unlikely. The eastern boundary is not far away, in western
Arizona. Stations west and north of LA in a narrow coastal band will
have some mutual darkness---more at the beginning of the DXpedition, and
less at the end. For example, the Bay Area may have a 15 minute window
on April 1, and 9 minutes on April 10. A similar situation exists for
many stations in the Great Basin, Rockies and Great Plains.

Those interested can examine this phenomenon with popular propagation
programs, such as MiniProp. The situation is slightly improved on 80
meters, where absorption is a fourth as severe, allowing some
penetration of the dead zone by better-equipped stations.

In every DXpedition, some DXers will feast and others will go hungry. We
will do our best to fight hunger on topband. To do so, we require and
expect cooperation from the more fortunate. Please observe the splits.
Please do not comment on our TX frequency--wrong VFOers will figure it
out. Please respect the operators' requests. Be GENTLEMEN!

Good DX to all and we will see you in the pileups. 
Garry Shapiro, NI6T
160 meters: not a band, but an obsession

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