Mike, the measurements I took here on a short (300ft) WD-1A with average height of 5ft using the method W8JI recommends with a termination resistor (pot) and MFJ-259 showed an impedance of 140 ohms on both 160 and 80 meters. I did not attempt to measure at higher freq's...de gary, kd9sv
-----Original Message----- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of Mike Waters Sent: Monday, July 23, 2012 10:13 AM To: topband Subject: Re: Topband: WD1A I think the characteristics of so-called WD-1 surplus phone line varies. FWIW, the two short samples of WD-1 that I have here are as follows: 115 ohms impedance, calculated from the following: .033 diameter (averaged), .0685 spacing. The dielectric constant of the insulation (polyethylene) is 2.2. I just made three transformers for someone using that line as a bi-directional Beverage, but I think more tests need to be run to see how it really works in actual practice. But so far, so good. :-) 73, Mike www.w0btu.com On Mon, Jul 23, 2012 at 8:43 AM, Tom W8JI <w...@w8ji.com> wrote: > Has anyone ever made any attempt to characterize the line at HF? > _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK