Hi Ray,
Suggest you use two porcelain insulators in series. I have some long porcelain insulators that might be a better long term solution. 73 Frank W3LPL ----- Original Message ----- From: "Raymond Benny" <[email protected]> To: "160" <[email protected]> Sent: Thursday, February 1, 2018 2:20:24 AM Subject: Topband: High voltage insulator I need the experience and wisdom of this group. I have am 80m vertical hanging off the side of my 160m vertical and share the common radial system. The 160m vertical is 4" and 3" irrigation pipe, 72 ft tall with 4 - 30ft top hat wires and a loading coil at the base. The 80m vertical is up 68 ft and hangs from a 14" side arms and has its own coax and loading coil. I have to short the 160m vertical to ground to operate 80m. I run near 1500w output. The problem is that the 80m insulator at the top shorts and arcs out over time. I understand there is perhaps 6 - 10 KV at the top of the 1/4 wave 80m vertical. I can see it now arcing at night and my swr is jumping between 1.5 to 2.0. My original insulator what just a small, abt 1" x 2" white porcelain wire insulator that lasted for 2 - 3 years before it cracked and shorted due to mechanical strains. My second was some sort of composite insulate about 1" x 4" long that lasted abt a month before it melted. My last insulator that is arcing, I think it is some sort of porcelain insulator. Maybe its cracked too. I am tilting down the vertical tmw to replace the insulator and want to get some ideas as what to replace it with. I have both white and brown guy wire insulators, about 1 - 1/2" dia by 3" long, or I'm wondering if a synthetic material type might work the best. I have three pieces of synthetic rods, about 3/4 to 1" dia. One is from the center insulator of a yagi driven insulator from my junk box and about 1" dia by 8" long. I think its fiberglass, but not sure. I also have from my junk box, one round stock that might be Delron another and other might be Teflon or some other synthetic material. I just placed the 3 pieces in the microwave with a cup of water. After 2 minutes, all three were slightly warm. After a second 2 minutes hit, two of the synthetic types were very hot. The yagi dipole center insulator which I think is fiberglass was still only slight hot. So, what conclusions can I deduce? Which one might be best for my use? I'm tending towards using one of the porcelain insulators. Any thought or experiences? Are there more tests I can do on the synthetic material rods? Tnx for your thoughts and recommendations. Ray, N6VR Near Prescott, AZ -- Ray, N6VR _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
