Topband: Measured RG-6 Loss: Solid Copper vs. Copper Clad center conductor

[jeremy maris]

I posted earlier  on the list  (31 January 2011 ) problems we had with  some cheap  ebay "satellite cable"  CCS RG6 that I was using on a long run to 160m Beverages. The 250m reels came from different suppliers, though both of Chinese origin.

"The measured loss in the first 250m segment was ~ 6dB and about ~9dB  in the second segment, 15dB total over 500m. This is way higher than published figures (eg at http://www.timesmicrowave.com/cgi-bin/calculate.pl)  which suggest about 3dB per 250m."

This is in line with your  attenuation measurments of CCS  (0.6 dB loss per 100 ft at 1.8MHz) , but shows that cheap cable can be even worse! 

I assumed  that this  cable was particularly bad at lower frequencies because of "value engineering" re the thickness of the copper coating.

Rudy N6LF gives the skin depth at 2MHz as 40uM (Conductors for HF  Antennas, Rudy Severns, QEX November/December 2000) and I guess that some  CCS cable has copper  covering much thinner than that!

No doubt  quality Comscope or Belden is better, but we stripped out the RG6 and used solid copper CX167 instead, more expensive but very useable over a 1km feed run.

Jeremy G3XDK/G4AQG


On 24 Jan 2013, at 02:28, <donovanf at starpower.net> <donovanf at starpower.net> wrote:

> Hi Mike,
> 
> Obviously I had computers on my mind...
> 
> Yes, of course I meant to say quad-shield RG-6 CATV cable.   I'll provide the manufacturers and part numbers in a subsequent e-mail, but its just typical inexpensive ebay RG-6 CATV cable.
> 
> Inexpensive RG-6 with a copper clad steel (CCS) center conductor is much more widely available than solid copper, especially in desirable options such as a tough polyethylene (PE) jacket and flooded RG-6.  CCS looks like a reasonable choice except for very long cable runs on 160 and 80 meters.  A copper clad center conductor may be a problem if a device (e.g. a preamp or relay) is remotely powered through the coaxial cable.
> 
> 73
> Frank
> W3LPL
> 
> ---- Original message ----
>> Date: Wed, 23 Jan 2013 19:56:40 -0600
>> From: Mike Waters <mikewate at gmail.com>  
>> Subject: Re: Topband: Measured RG-6 Loss: Solid Copper vs. Copper Clad center conductor  
>> To: topband <topband at contesting.com>
>> 
>>  Hello Frank,
>> 
>>  Thank you for this, but you meant "quad-shield" instead of
>>  "quad-core", didn't you? I've never heard of coax with 4
>>  cores, unless you mean the quad-coax stuff where the jackets
>>  are all joined together.
>> 
>>  Data on the coax companies and part numbers might be useful,
>>  if you have it handy.
>> 
>>  73, Mike
>>  www.w0btu.com
>> 
>>  On Wed, Jan 23, 2013 at 4:58 PM, <donovanf at starpower.net>
>>  wrote:
>> 
>>    copper clad steel (CCS) Quad-Core RG-6 coaxial cable.
> _________________
> Topband Reflector