[TowerTalk] RFS LCF158-50JA 1-5/8" Heliax

[Byron Tatum]

Hello-    Just a quick question and some notes here regarding the RFS LCF158-50JA (1-5/8") Heliax. I am getting a few runs ready for installation on my towers for VHF/UHF systems. I had picked up the manufacturer's "premium" connectors, the RFS 716F-LCF158-D01K. I am using 7-16 DIN connectors on tower runs. I obtained the spanner wrenches for these connectors.     These RFS connectors make contact with the center conductor using small spring fingers that slip inside the center conductor copper tube a very short distance. I had read that the Andrew AL7DF-PS connector will fit the RFS LCF158-50 cable. I had picked up a few of the Andrew connectors when I obtained the RFS connectors. I compared the two connectors and it appears to me the Andrew AL7DF-PS connector would be more desirable based on the construction of the center conductor contact mechanism. The Andrew connector has a much longer (silver plated) and more massive contact assembly that inserts into center conductor much further than the RFS connector. Both connectors make contact to the outer conductor in a similar manner. The Andrew connector has more O-ring seals.    I was curious if anyone else has had a similar experience as me with this cable and connectors. I assembled one of each type to the cable and it appears to me I prefer the Andrew connector based on the two inch long center conductor contact assembly. It appears to me the RFS connector has only about 1/2 inch (insertion) contact to center conductor ID. I am curious if in long term use of the RFS connector this very short insertion length of the center conductor contact fingers could be a trouble area?      I did experiment with an older 1-5/8" Andrew connector, the L7-PDF. I really liked that (solid) center conductor contact piece that threaded into the internal spirals of the center conductor on the old LDF7-50 cable. However, this RFS LCF158-50 cable has a slightly larger ID of the center conductor than the older LDF7-50 Andrew cable and the L7-PDF connector center conductor threaded piece makes a very sloppy fit. It will tighten up against the internal spiral but I would not trust it long term.     I made up a 160' piece of the RFS cable using the Andrew AL7DF-PS connectors and it tested to spec regarding SWR and loss when tested at highest frequency of use here (1296 Mhz). So I am thinking of going with these connectors.     Just curious if anyone else has experience with connectors for the RFS LCF158-50 cable.Byron W5FH