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Fig. 14 shows a basic dual final installation with the class C bias mod on a galaxy DX 99V. Points A, B & C
depict the locations of inductors L47, L50 & L35. These three inductors act as an RF choke when applying
the bias voltage to the base of the driver and finals so that the RF does not pass into the DC bias circuit.
There are 3 types of inductors that are commonly used, and they can be seen on Fig 12; 1- ferrite, 2-
f resistor combination and 3- dipped axial inductor, their value should be about 22uH.
Most transceivers use the F Resistor
combination, but any of the three types in
Fig. 12 can be used.
Fig 12
To convert to class C bias, simply unsolder inductors L47, L50 & L35 from the resistor side at points A, B
& C, as seen on Fig. 14, which is the side that should be connected to the bias circuit, in this case, VR11,
VR20 & VR10. The ferrite side should be
connected to the base of the driver and
final transistors. Make sure you do not
unsolder it from the base of the
transistors. Finally, solder all three
resistor sides to board ground.
Alternatively, and simpler, the inductors
can be completely removed from the
board and installed on the
bottom/copper side of the board as seen
done with the dipped axial type inductors
on Fig 13.
Fig 13
Summary of Contents for IIIs
Page 5: ... 5 ...
Page 8: ... 8 Audio Input Connections ...
Page 17: ... 17 Installation Block Diagram Installation for Other Transceivers ...
Page 22: ... 22 Fig 9 Fig 10 ...
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Page 34: ... 34 Asymod IIIs Stryker SR 955HPC Settings Specifications ...
Page 41: ... 41 Asymod IIIs Cobra 2000GTL Installation eSSB Settings Specifications ...
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