The braid configuration and the expanded PTFE dielectrics of the LL cable constructions contribute to lower attenuation levels at higher frequencies, while providing shielding effectiveness levels that exceed those of flexible MIL-DTL-17 cables. Flat strips of silver plated copper are braided over the dielectric core with an intermediate metallized polyester or polyimide layer, and an outer round wire braid.
Harbour’s LL cables with expanded PTFE dielectrics exhibit low coefficients of expansion over the entire operating temperature range from -55° C to +200° C. Impedance discontinuities are minimized at the cable-to-connector interface. Higher levels of power can be transmitted because higher temperatures do not affect the cable due to the thermal stability of the tape. Where phase versus temperature requirements are critical, Harbour’s LL cables allow for an approximately 75% lower phase shift and change in propagation time delay due to temperature. Temperature cycling tests have been performed on a number of Harbour’s cables with positive results.
Harbour’s LL coaxial cables, with expanded PTFE dielectrics and strip braid composite configurations, offer attenuation from 20 to 35% below other mil spec cables of comparable size. When size and weight are considerations, Harbour’s LL cables should be considered.
Special constructions are the norm rather than the exception, so please make sure you contact Harbour Industries firstname.lastname@example.org if you don’t see the specific construction for your application. Part numbers for some of the more common cable constructions are LL142STR, LL270STR, LL450STR, and LL480STR.
View a listing of connector manufacturers that mate with Harbour's LL (Low Loss) cables on the Industry Links page.