[TenTec] TWINCOM feedline ?????????????

Stuart Rohre rohre@arlut.utexas.edu
Mon, 14 Oct 2002 17:44:29 -0500


George, Sorry there is no free lunch.

Higher impedance lines are less lossy, that is true.  But, the Twincom
appears to be twin coax, and has an obvious dielectric around the wire in
the picture.  Thus, it will be lossy-- as coax is lossy, much more so than
ladder line, 450 ohm at 69 cents a foot. At least twice as lossy because its
impedance is that much lower than ladder line.  Note the price on Twincom,
which was in Euros, 2.64, Are they not about equal to just less than a
dollar, (1 Euro 1 Dollar?)

Ladder line is so much easier to handle than a twin coax, it is cheaper,
lower loss, and more compact, and easier to run.

You can just put some insulation under the window sash and run the ladder
line at right angles to the window frame and you have low loss and it can
then go right to the transmatch in the shack.  Some folks locate the
transmatch at the window, and tolerate some coax loss from there to rig.

In either case, the bulk and weight are less than running TWINCOM all the
distance.  And shipping from Europe would run the cost up that much more.
73,
Stuart K5KVH