The reason for wanting to know the above is, I want to use RG58 inside the
box and then run RG213 up to the box for the feeder from the radio. I don't
want to do this if the S0239 socket is going to allow the feed line to
radiate. Can any one please advise?

Many thanks


"Barrett" wrote in message
k...
I have some questions about the choke and feed line on the Cobwebb.



Does the co-axial choke balun work better if the cable is wound on top of
each other into a tube shape rather than just winding it round and zip
tying it together in a round bundle?



Can I attach a SO239 Chassis socket to the end of the box where the coax
enters and then plug a PL259 into that for the feeder or will the socket
allow current to bypass the choke balun and enter the feed line?



Thanks

On Thu, 20 Mar 2008 22:43:25 GMT, "Barrett"
wrote:

I don't
want to do this if the S0239 socket is going to allow the feed line

Feedline radiation is a consequence of common mode currents. Common
mode currents are a consequence of unbalance. Coax systems are
unbalanced. To correct this, you need to choke the coax line at the
feed point, and probably again a quarterwave away from the feedpoint.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Thu, 20 Mar 2008 22:43:25 GMT, "Barrett"
wrote:

I don't
want to do this if the S0239 socket is going to allow the feed line

Feedline radiation is a consequence of common mode currents. Common
mode currents are a consequence of unbalance. Coax systems are
unbalanced. To correct this, you need to choke the coax line at the
feed point, and probably again a quarterwave away from the feedpoint.

Coax feedlines are no more or less balanced than twinlead lines. Common
mode current can occur on either, and for the same reasons, and either
can be balanced by suppressing or avoiding creation of common mode
current. The topic is discussed in more detail at
http://eznec.com/Amateur/Articles/Baluns.pdf.

Roy Lewallen, W7EL