Cecil Moore wrote:
Reg Edwards wrote:

You will get all sorts of technical reasons for lower loss. But
essentially -

The wires in high impedance balanced pair lines are thicker than
the
inner conductor of coaxial lines.

Thicker wires mean lower resistance.

Lower resistance means lower loss.

That is true. But the number one reason that matched line loss
for 450 ohm ladder-line is lower than matched line loss for RG-213
at HF is the effect of (characteristic impedance =3D load) which is
the same effect as Ohm's law.

Given RG-213 vs 450 ohm ladder-line the losses are *roughly*
equal when:

SWR(coax)/50 =3D SWR(ladder-line)/450

or, in general, when:

SWR1/Z01 =3D SWR2/Z02

Wunnerful. But out here in the realities of practical (God forbid)
applications of the various types of backyard feedlines there's a
persistent rumor going back decades to the effect that decent open-wire
feedlines have significantly lower dielectric losses than "ham-level"
coax under all VSWR condx. So there are conductor *and* dielectric I=B2R
losses to consider in this discussion yes?

--
73, Cecil http://www.qsl.net/w5dxp

w3rv


----=3D=3D Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet
News=3D=3D----
http://www.newsfeeds.com The #1 Newsgroup Service in the World!
120,000+ Newsgroups
----=3D East and West-Coast Server Farms - Total Privacy via Encryption
=3D----