RF choke with coax

[David Waits]

I have RG8/U coax on my A-99, how many coils and what diameter(Inside or outside) do I make for an RF choke. Coax has a 85% braid on top of foil, a 9.5 gauge stranded center conductor and a velocity factor of 85%?

 

[bob85]

i use 5 turns on a 4.25" former, tape it up and pull the former out,
have a look at g3txq's chart for rg213 @27mhz,
http://www.karinya.net/g3txq/chokes/

 

[David Waits]

So Bob, do you think the same formula will work with my RG8/U?

 

[bob85]

its the same physical size outer brade or very close so yes it should.

 

[David Waits]

Okay, thanks!

 

[9C1Driver]

On one of my computers I saved a link for a balun choke chart, it had both a frequency and type of coax break down to it as I recall.

 

[9C1Driver]

Can't find the edit button but here it is.
http://s3.zetaboards.com/copythat/topic/7519444/1/