I saw an eBay listing for 305m (1000′) rolls of Commscope 4510404 CCS RG11A/U which looked interesting, time for some due diligence.
Being a brand name product, specifications were probably available and indeed were quickly found.
The cable is a CCS RG11A/U (Zo=75Ω), and from the centre conductor DC resistance value (12.5Ω/305m) and 1.63mm (#14) size, it appeared likely that it was 21% IACS Copperweld, and that the cladding thickness should be 49µm. At that copper thickness, near copper like performance was likely down to perhaps 7MHz (where it is 2 skin depths thick).
A roll was ordered as it was likely to be quite usable cable and at $99 including shipping (~25kg) it should be good value. Continue reading Checkout of a roll of Commscope 4510404 CCS RG11A/U
The technique is to make a measurement near to the frequency of interest of Rin at resonance of the length of line with open circuit at the far end, and to calculate the matched line loss (MLL) using Calculate transmission line Matched Line Loss from Rin of o/c or s/c resonant section.
Let’s demonstrate the measurement of Rin of an o/c resonant section around the 160m band, which we will then use to calculate MLL.
Above, the AA-600 connected to the cable using a F(F)-N(M) adapter, the cable is 305m in length and the far end is open circuit. Continue reading A walkthrough of using a Rigexpert AA-600 to make a quick measurement of loss of a new roll of CCS RG11
A model of current distribution in copper clad steel conductors at RF described a simple analytical model. This article compares the results of that model with graphs published in (Severns 2000) and is of particular interest since Severns used an FEA based model.
Above is Fig 3A from Severns and is the current distribution at 1MHz for 20.3µm (0.0008″) cladding of a 0.405mm (#26) CCS (Copperweld) conductor. Continue reading A model of current distribution in copper clad steel conductors at RF – comparison with Severns 2000