Johnson KW Matchbox
 

Will a 50ohm to 112ohm unun current balun on the input side of the
matchbox increase the output capability to handle an open wire fed
80meter dipole at 65' on 40meters? I am 'kinda' stuck with my feedline
length of 80ft, so thought I would raise the input impedance to boost
the output impedance capability. I am aiming for a 1 to 1 'indicated'
VSWR. The differential cap is fully meshed (rotor to top plates) and the
other cap is approx 50% meshed and the matchbox input VSWR is approx 2
to 1.
What say?

Johnson KW Matchbox
 

Bill wrote:
Will a 50ohm to 112ohm unun current balun on the input side of the
matchbox increase the output capability to handle an open wire fed
80meter dipole at 65' on 40meters? I am 'kinda' stuck with my feedline
length of 80ft, so thought I would raise the input impedance to boost
the output impedance capability. I am aiming for a 1 to 1 'indicated'
VSWR. The differential cap is fully meshed (rotor to top plates) and the
other cap is approx 50% meshed and the matchbox input VSWR is approx 2
to 1. What say?

My notuner antenna at http://www.qsl.net/w5dxp/notuner.htm is pretty
close to what you have. Increasing your feedline length to 94-100 ft.
might solve your problem without the unun. The unun actually could
make the problem worse since you don't know if that 2:1 SWR is 100
ohms or 25 ohms or something in between with reactance.
--
73, Cecil http://www.qsl.net/w5dxp