Several topbanders asked if I would measure the DC resistance of the solid copper and copper clad steel center conductors of the RG-6 coax for which I published the RF loss measurements. I also measured the quad-shield DC resistance, both cables measured the same.
Here are my measurement results: Solid copper: 0.6 ohms per 100 feet Copper clad steel: 1.9 ohms per 100 feet Quad shield: 0.3 ohms per 100 feet It appears that copper clad steel RG-6 is a good choice for remote powered preamps and relays except for very long cable runs. When using a remotely powered device its extremely important to prevent even the slightest moisture entry. RG-6 compression connectors are NOT waterproofed at the threaded end of the connector, additional waterproofing is absolutely essential. The Thomas & Betts NS500 Nut Seal costs only a few cents and it very effectively waterproofs the connector threads. http://www.ebay.com/itm/NEW-LRC-AUGAT-THOMAS-BETTS-NS-500-NUT-SEAL-50-LOT-/160703026841 The inside of the connector should be stuffed with STUF Di-Electric Filler to prevent moisture accumulation from condensation. The finished connection should first be wrapped with electrical tape, then a final layer of waterproofing should be applied such as Coax-Seal moldable tape. 73 Frank W3LPL ---- Original message ---- >Date: Wed, 23 Jan 2013 17:58:31 -0500 (EST) >From: <[email protected]> >Subject: Measured RG-6 Loss: Solid Copper vs. Copper Clad center conductor >To: [email protected] > >Today I measured the difference in loss (dB per 100 ft) between solid copper >(SC) center conductor RG-6 vs. copper clad steel (CCS) Quad-Core RG-6 coaxial >cable. The difference is not significant until cable lengths exceed 350 feet. > You can see the affect of the steel core at 7 MHz and below in this table. > >The cables were manufactured by two different companies, but the relative >measurements should be valid. > > Solid Copper Cable length in >Freq Copper Clad feet for a 1 dB >MHz Loss Loss loss difference > >1.8 0.3 0.6 350 >3.5 0.4 0.6 500 >7.0 0.6 0.8 500 >10 0.7 0.85 650 >14 0.75 0.9 650 >21 0.9 1.0 1000 >28 1.0 1.1 1000 > >73 >Frank >W3LPL _________________ Topband Reflector
