Petersen Radio Co
Pr Crystal Z-9R (aircraft)
Pr Crystal Z-9R (cb/rc)
Pr Crystal 2XP (3RD Overtone)
Pr Crystal 2XP (fundamental)
Pr Crystal Z-1 Tv Marker FM IF
Pr Crystal Z-1 Tv Marker (signal Generator)
Pr Crystal Z-1 Tv Marker (intercarrier)
Pr Crystal Z-1 Tv Marker (channel)
Channels 2 thru 13