Extra Flexible Coaxial Cable

摘要

New freeze-resistant materials were evaluated for radiofrequency coaxial cables. MIL-C-17 coaxial cables having Type A polyethylene dielectric cores and Type IIa noncontaminating (nitrile rubber plasticized) polyvinyl chloride jacketing were found too stiff at subzero temper atures; vinyl jacketing cracked even above -40C. A blend of poly-alphaolefin with polyethylene was found to be electrically equivalent to polyethylene up to at least 10 Gc, and only 1/3 as stiff at -40 and -55C. Two thermoplastic polyester type urethanes and an ethylene copolymer jacketing material were found more flexible than vinyl down to -55C. The urethanes degrade after a long period of time at high humidity, but should be considerably better than polyolefins in abrasion resistance. (Author)