I designed a loop for 100 ohm impedance and fed with coax and 1/4 wave
transformer. It has worked well for years. I got the bright idea to
replace the coaxial feed with 35' of 450 ohm ladder line and a Bliss
remote tuner. This combination would not match. I experimented. A
nice dip in VSWR was noted about 400kHz lower than the bottom of the
band where that combination of antenna plus ladder line was almost
perfectly resonant. A versa tuner WOULD tune it but I needed to add
about 90' of ladder line for the remote tuner to produce a reasonable
lower complex impedance inside the band (actually it was reduced to
about 58 + j6). The impedance with 35' of line was over 1K and this is
too large of a value for that tuner to accept. (That is a previously
made tuner with vacuum capacitor and large roller inductor.) Does
anyone have knowledge or experience with impedance transformation on
ladder lines that might be able to teach me something here about the
effects I noted??? Thanks.
--
David J Rodman MD
Assistant Clinical Professor
Department of Ophthalmology
SUNY/Buffalo
Office 716-857-8654
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