SB SPCL @ ARRL $ARLX021
ARLX021 First 120 GHz contact
QST de W1AW
Special Bulletin 21  ARLX021
From ARRL Headquarters
Newington CT  July 13, 1994
To all radio amateurs

First 120 GHz contact

Tom Williams, WA1MBA, and Jim Mead, WB2BYW, have made what is
believed to be the first contact on the 120-GHz amateur band.  Their
CW contact, over a 1.15-km path, was made with both in grid FN32rj,
at 1214 UTC, July 11, 1994.  They made contact first at a distance
of 2 meters, then 200 meters, then 950 meters, failed to make
contact at 1.9 km, and went back to the successful 1.15-km path.

The two hams' equipment consisted of 11-GHz rigs fed into a harmonic
mixer, using the 11th harmonic to produce 10 microwatts of 120-GHz
output into 0.3-meter dishes.  The mixers were commercial units
built by Pacific Millimeter Products, and the dishes were on loan
from the University of Massachusetts.

These two hams made contact on 145 Ghz in 1993, and point out that
120 GHz is more difficult because of the oxygen absorption at that
frequency.  Happy with their successes, Tom and Jim are already
talking about the possibility of trying 245 GHz next year.

When asked for advice to others who would try worked the superhighs,
Tom said, "Read a lot.  And plan your system carefully."  Tom added
that commercial mixers are very expensive (in the 1000 dollar(s) class), but
that experimenters are starting to come forward with designs for
home brew mixers at reasonable prices.

Congratulations are due WA1MBA and WB2BYW for what appears to be a
new record.
/EX