For years I've used a a Z-match tuner I built using very husky components - big transmitting variables, salvaged 3" diameter silver plated tank coil and a 9:1 gear reduction drive for the main tuning cap. It works very well tuning a doublet fed with 450 ohm window line -- but even with the 9:1 reduction tuning can be very sharp. It's also more sensitive to slight variations caused by antenna movement etc. since you're tuning for near resonance. Those may be reasons it wasn't commercialised (much). In comparison, the Palstar BT1500A balanced L tuner I acquired a while back is less "fussy" - tuning isn't nearly as fast or critical. It also has the virtue of highly repeatable settings - it's quicker and easier to hop from band to band.
Bob NW8L On Wed, Jul 15, 2009 at 3:44 AM, <d.cut...@ntlworld.com> wrote: > Can anyone point to why the single coil Z match wasn't commercialised rather > than the T match? (Perhaps it's a historical thing and manufacturers just > copy each other, notwithstanding the Johnson Matchbox of course, which is no > longer produced.) > > I'm in process of building one to cover 160 to 10 from VK2BR (?). I'm hoping > that the link coupling will help with "balanced" feeders and antennas, though > one side is bound to have more capacitance to earth than the other, so > "balanced" is fairly relative. > > David > G3UNA ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
