From the ARRL:
When the five new 60-meter channels become available to US Amateur Radio operators at midnight (12 AM) local time on July 3, the rules will impose a new record-keeping requirement for hams. The requirement applies only to those using something other than a simple half-wave dipole on the 5 MHz allocation.
According to Part 97.303(s), a half-wave dipole on the 5 MHz allocation will be presumed to have a gain of 0 dBd. ”Licensees using other antennas must maintain in their station records either manufacturer data on the antenna gain or calculations of the antenna gain,” states the newest addition to the FCC’s Amateur Service rules.
Because the new rules also require hams to run no more than 50 W effective radiated power (ERP) on the new channels, the choice of antenna becomes an important compliance factor. The FCC rules stipulate, ”For the purpose of computing ERP, the transmitter PEP will be multiplied (by) the antenna gain relative to a dipole or the equivalent calculation in decibels.”
ARRL has posted a list of frequently asked questions (FAQ)concerning 5 MHz operation on the ARRL Web site, www.arrl.org/fandes/field/regulations/faq.html#sixty .