Amplifier (Lewyt type ED-1) - USA Voorschrift, Technical Manual, 11-2585 Fortifications field manual Combat in fortified areas and towns. - USA Voorschrift, Field Manual, 31-50 Amplifiers BC-1388, BC-1388-A, BC-1388-B, BC-1388-C, and frequency amplifier AM-844/U - USA Voorschrift, Technical Manual, 11-2556 AF Amplifier AM-65 FR/GRC : French Production (Furnished in lieu of TM 11-5039) - USA Voorschrift, Technical Manual, 11-5039