Such a cable has practical no attenuation on 160 meter. You can simply do all the tuning in the shack.
Verzonden vanuit Mail voor Windows 10 Van: Ron WV4P Verzonden: zaterdag 16 mei 2020 23:46 Aan: Richard (Rick) Karlquist CC: Rob Atkinson; 160 Onderwerp: Re: Topband: 160m Vertical Thanks again for all the replies, it kind of jumped around on my end between on and off list replies. Hopefully I have not missed any. The Feedline will be ~300' of 7/8 CellFlex. Legal Limit on power. About 8000' of Radials, In theory, 64 @ 120' but rough terrain will necessitate some flexibility. So far from the replies I have come up with. - ~115' Of Rohn 25 resonate high in the band. - An Air Core Inductor at the base with 4 taps, switched with relays to make it usable across the band. - A Shunt Coil for static bleed and to bring the feed-point impedance up to ~50 ohms Ron, WV4P On Sat, 16 May 2020 at 12:56, Richard (Rick) Karlquist < rich...@karlquist.com> wrote: > On 5/16/2020 4:31 AM, Rob Atkinson wrote: > > On 5/15/2020 8:27 AM, donov...@starpower.net wrote: > > > > ""A more reliable approach is a tuner in your shack. The extra coax > > cable loss from elevated VSWR is insignificant on topband."" > > > > > > Another disadvantage of a tuner at the shack end is that the match > bandwidth for any given setting of the tuner becomes narrower. > I have over a full wavelength of open wire line to my 160m > vertical. No problem with power handling, VSWR handling or loss, > but the match bandwidth is very narrow if the OWL is badly > mismatched. There is a 450 ohm to 50 ohm balun/transformer at > the tower, so I only have to match the antenna to unbalanced > 50 ohms. There is another transformer at the shack end. > > I should also point out that the charts showing "Additional loss > due to SWR" were incorrect for decades in various ham publications > and were only recently corrected, in case you hadn't heard. > > See: > > https://ac6la.com/swrloss.html > > Rick N6RK > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector