ve2pid wrote:
Hi to all

When running a length of TX line through an environment where it is
susceptible to contact leaves or maybe branches, what is the best
choice.. window ladder line or coaxial wire?

In other words, will both of these type of lines have about the same
loss to natural environment objects or is one more sensible than the
other?

I am not talking about SWR losses or matched line losses.

Thanks de VE2PID

The short answer is coax.

When properly balanced (that is, common mode current suppressed),
coaxial cable is totally insensitive to its electrical environment.
Ladder, window, and other types of twinlead line, however, are not.
They're most susceptible if the line has a high SWR and the contact with
water, other lossy material, or conductors occurs near a voltage peak,
but even when matched, considerable loss and/or impedance disturbances
can occur. There's very little good data on the effect of water, but I
made measurements of TV twinlead many years ago and found that it could
be lossier than even small coax when wet. Wes Stewart measured some
ladder line and found that it also could be quite lossy when wet. He
posted the results on this forum some years ago. While the loss
specifications of dry ladder line in an ideal environment are
attractive, it can easily become much lossier than coax when wet and in
close proximity to lossy materials such as leaves or damp wood.

Roy Lewallen, W7EL