Binocular transformer was made on ferrite tubes
used on the monitor cable. Through the tube was passed a length
of a coaxial cable with Teflon dielectric. Braid of the cable
was turn on to the transmitter inner wire was used for matching
symmetrical load. Figure 4
shows the binocular transformer and tapped inductor. Some different
ferrite tubes may be used at the binocular transformer. However
the ferrite tubes should be identical to each other and the transformer
should not heat on the used bands.
Rear panel of the cabinet of the tuner made of plexiglass.
All parts of the tuner have no electrical contact with the cabinet.
If at some reason the tuner do not provide symmetrical output (as usual
at lack of the montage) it is need to connect a variable capacitor
up to 30-pF to the ground and one of the output terminals. Then
with the help of oscilloscope tune the capacitor to the symmetrical
The S- Tuner was used with transceivers FT-817, FT-857 and antenna G5RV. SWR was not more 1,1 at 600- Ohm antenna impedance.
Author is very appreciated to RZ3DK and RZ3DOH for their publication and advices on the binocular transformer.
73! Eugene (RZ3AE)