JANET HANDOFF FREQUENCIES

121.9   McCarran Ground Control
119.9   McCarran Tower
133.95  Departure Control
119.35  Nellis Control
120.35  Groom Approach
127.65  Groom Tower
118.45  Groom Ground

Here are some other Groom freqs.
The security frequencies are usually scrambled, but not always.

418.05  Cammo Dudes (primary)
408.4   Cammo Dudes (repeat of 418.05)
142.2   Cammo Dudes
170.5   Cammo Dudes (Channel 3)
138.3   "Adjustment Net" (seems related to security)
261.1   Dreamland Control (published)
255.5   Groom Tower (repeat of 127.65)
154.86  Lincoln County Sheriff
496.25  Road sensors on public land
410.8   Pager (apparently from Groom but unconfirmed)

The most accurate way to detect a road sensor (AFTER you have tripped it),
is to program 496.25 into several channels of your scanner, then scan those
channels exclusively as you are driving.  When the scanner stops on one
channel, you have just passed a sensor.
