QST, Feb 1969, p. 107.
QST, Aug 1971, p. 116. (RF-550A, after Galaxy's merger with Hy-Gain)
Designed to match the GT-550. The RF-550 wattmeter read forward and reflected power on 400 and 4000 watt scales. A front-panel switch had positions for five antennas and a dummy load.
