[TowerTalk] Coax Loss -- RG-Numbers Don't Tell us Much

[jimlux]

Roger (K8RI) wrote:
> 
> Jim Brown wrote:
>> On Thu, 4 Feb 2010 10:38:19 -0800, Rick Karlquist wrote:
>>
>>   
>>> This is *generally* true, if comparing all copper cables.
>>> But even in that case, the HF loss is not proportional to
>>> DC resistance when comparing different sizes of cable.
>>> And all bets are off when copper plating is involved.
>>> It is also worth noting that Al has something like 1.6 times
>>> the DC resistance of Cu but only 1.3 times the RF resistance.
>>> Finally, 75 ohm cable has considerably more DC resistance than
>>> 50 ohm cable with the same RF loss.
>>>     
>> Rick,
>>
>> My point is that virtually all transmission line losses at HF are I squared R 
>> losses. 
> 
> That's why you want to install the largest coax you can afford.
> 


So, are we going to see articles in QST about "How to fabricate coax air 
line from thinwall 6" aluminum irrigation tubing" or " How I learned to 
stop worrying about rain on my openwire line and to love my TIG welder"