Henry really screwed up on this whole line of amps. They want you to supply a 4 wire 240/120 feed to the amp. Most hams who have a newer amp and adding these older amps do NOT have a 4 wire 240/120 feed to their amplifier outlet. Most hams have only a 3 wire feed. TWO hots and a ground. You should disregard what Henry asks you to do because they are wrong. The proper way to run these amps on a 3 wire dedicated 240v feed is to simply take a jumper and connect the #2 on the schematic above to the jumper at 3 and 4. Then you will now have 2,3,4 all connected together. Then feed the two hots of the 240v to 1 and 5. MAKE SURE THE GREEN (GROUND) ON THE RECEPACLE GOES TO THE CHASSIS OF THE AMP VIA THE AMP LINE CORD. The schematic above shows no ground but just make sure the green wire from amplifier cord is chassis grounded.