If you have access to Mathematica, you can use Array Gain notebook for computing and displaying the vertical plane pattern for vertically-stacked antennas over perfect ground. I’ve applied it to evaluate phasing combinations for steering the main lobe in the various stacks at KC1XX.
If you don’t have Mathematica and are curious about the algorithm or example results (for the 20m 4-stack), grab Array Gain Example.
Daytime Noise Floor Measurements shows data captured with the Elecraft P3 panadapter characterizing my receiving environment on the low bands.
CW Spectral Waveforms applies the Elecraft P3 to study CW keying for two radios and for an on-air signal.
2011 WW CW Pictures documents spectral data for several well-known East Coast contesters, captured Saturday afternoon on 40 and 80 meters.
K1DG Experiments describes on-air experiments to examine the effects of sending speed, amplifier mis-adjustment, and transceiver rise-time setting for two transceivers and two amplifiers.
W1WEF Experiments describes on-air experiments to examine the effect of FT5K rise time setting.
This diagram is a complete schematic of the receive signal paths in a fully-tricked-out K3.