Introduction
GR-3 Operator’s Manual
1-22
The PG-A1 GPS antenna for GB-500/1000 packages is a dual-
frequency GPS/GLONASS antenna (Figure 1-12). The optional
ground plane helps to eliminate multipath errors.
Figure 1-12. PG-A1 GPS Antenna
Optional Accessories
Topcon offers a wide variety of accessories especially designed to
extend job reliability and efficiency. For more details on the optional
accessories available for the GR-3, contact the local Topcon dealer.
The precision tribrach adapter (Figure 1-13) is used to precisely
center, align, and level the tripod over a point. The horizontal spacer
(p/n 60419) inserts into the precision tribrach and allows the receiver
to sit securely on the precision tribrach.
Figure 1-13. Precision Tribrach Adapter and Horizontal Spacer
The quick disconnect adapter (p/n 02-850905-01) connects to the
range pole for the receiver to slip into the top. Using the side clips, the