VLBA RFI Bulletin 9:  Ft Sumner NM Balloon Launch:

The National Scientific Balloon Facility (NSBF) has just announced a
planned high altitude balloon launch for late this afternoon, Tuesday,
March 17, 1998 from Ft Sumner in eastern New Mexico.  The balloon is
scheduled to stay east and north of any NM or TX VLBA station observing
range.  However, during previous NSBF missions planned for northwest
Texas, chaging wind conditions after the launch have occasionally
caused the balloon to drift over the VLBA-PT, VLBA-LA, or VLBA-FD
sites, causing significant L-band interference. Observers should be
aware of an increased potential for RFI at the following L-band
frequencies:


  	1444.5    MHz
	1501.5    MHz