Garmin GPS 400 Pilot's Manual And Reference page 90

5 5 WPT PAGES
PROCEDURES
Airport Frequencies
Approach Examples
Œ

b
Some listed frequencies may include designations for limited usage, as follows:
"TX" - transmit only
"PT" - part time frequency
If a listed frequency has sector or altitude restrictions, the frequency will be pre-
ceded by an "Info?" designation.
To view usage restrictions for a frequency:
E
d
r
"RX" - receive only
d
E