**5.19.4 RS103 alternative test procedures – reverberation chamber
(mode-tuned).**

These procedures may be substituted for the 5.19.3 procedures over
the frequency range of 200 MHz to 40 GHz. The lower frequency limit is
dependent on chamber size. To determine the MIL-STD-461E lower frequency limit
for a given chamber, use the following formula to determine the number of
possible modes (N) which can exist at a given frequency. If, for a given
frequency, N is less than 100 then the chamber should not be used at or below
that frequency.

where: a, b, and d are the chamber
internal dimensions in meters |

f is the operation frequency in Hz c is the speed of
propagation (3 x 10^{8}
m/s) |