I put ~1500 lights (mini incans) on a large oak tree today. I figured I would just keep stringing them in series until I blew a fuse on the first string, then power up from that point on with a "new" 120 VAC feed. Well, I ran into an interesting problem. I did blow a fuse; replaced it and everything was good. But I kept having about 500 lights dim, then go out, then come back on periodically. So I picked a point relatively close to the "center" of the strings and a point near the top 1/3 of the strings and provided each of those with separate power feeds. After that, no more dimming or going out. Just figured I would share with others.... I am figuring perhaps the "shunts" in the light strings may have resulted in some voltage drops or something. Not worth troubleshooting; I just added some new feeds with vampire plugs and SPT-2 wire.