Topband: Coax VF

[Tom Rauch]

>>While researching the topic of receiving arrays it seems 
>>that I read
>>in ON4UN a rather ominous recommendation that foam 
>>dielectric be
>>avoided for use as phasing lines, the reason being that 
>>the VF does
>>not remain constant with time & temperature. He 
>>recommended using
>>only solid dielectric coax for that purpose.  I know this 
>>isn't what
>>you wanted to hear, but it may save you a lot of grief 
>>down the
>>road.  I will try to find the exact paragraph in the 
>>latest ON4UN book.

I've never heard of that concern before.

We certainly never worried about it in BC systems (they 
almost exclusively used foam dielectric cables) and I never 
worry about it in my Ham stuff. I can't imagine why the foam 
cable would be any worse than any other cable of similar 
quality.

73 Tom