*Don’t* use the two conductors of a single run of twisted pair WD-1A as the transmission line - you’ll get a *lot* of loss in the transmission line. Instead parallel the two wires and run two lengths WD-1A (as Jim Garland says). 2 inches / 50mm spacing between them will give a line impedance of around 450 ohms, and much less loss.
Jeremy G3XDK / G4AQG > On 12 Jan 2020, at 23:24, Herbert Schoenbohm <[email protected]> > wrote: > > Probably the most durable two conductor is Military WD-1A telephone cable. > available on eBay for $50 for about a half-mile. Special lower > impedance transformers are required to match the line's impedance. It is > also a great source for very durable single wire Beverages with both ends > connected together. > > Herb, KV4FZ > > On Sun, Jan 12, 2020 at 11:26 AM John Kaufmann via Topband < > [email protected]> wrote: > >> I'm looking for a source for durable ladder line for making two-wire >> reversible Beverages for use at the KC1XX contest station. In the past >> we've used the line sold by DX Engineering but over the years we've found >> that the plastic spacers between the wires become brittle and break off. >> It >> may be UV exposure that causes this. We also get some pretty severe >> weather >> at KC1XX hilltop location, with ice in the winter and frequent strong >> winds. >> The spacer breakage sometimes exposes the wires, which then become twisted, >> and the ladder line generally becomes weakened and prone to wire breakage. >> >> >> >> What else is available commercially? >> >> >> >> 73, John W1FV >> >> _________________ >> Searchable Archives: http://www.contesting.com/_topband - Topband >> Reflector >> > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector Jeremy Maris 140 Edward Street, Brighton BN2 0JL [email protected] _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
