Select a picture for larger image.

  RSSI line - The solid line on the bottom is at 0.6 VDC, which corresponds to a -80 dBm received signal level for the LMX2240 IF receiver.  The peaks are syncronized to the frequency hopping and are at around 1.6 VDC, which corresponds to a -20 dBm received signal level.

  RSSI line - Picture 2

  RSSI line - Picture 3

  RSSI line - Receiving some interference.  Probably all those darn Part 15 transmitters...

  PIN diode bias line (going to RF power amplifier) - +5 VDC on transmit, 0 VDC on receive.  The other leg on the PIN diode goes to the receive section and is +5 VDC on receive and 0 VDC on transmit.