Model K
EXPO 100 EXPANDER
Instructions
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1. |
Remove the covers from the unit and rewove the 11.3258 crystal next to PLL chip MB8734. |
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2. |
Plug the removed crystal into the expander board and mount the expander by drilling a hole in the cabinet as close to the crystal socket as possible. |
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3. |
Solder the wires from the expander board to the crystal socket keeping the wire as short as possible. |
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4. |
Place the provided label to the side of the switch and position the knob to correspond. |
Slider
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1. |
Follow the wires from each end terminal of the clarifier control and cut them at the board. |
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2. |
Solder right terminal of clarifier to ground, and left terminal to the (+) side of C66 behind the chip. |
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3. |
Cut diode D36 just in front of the PLL chip. |
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4. |
Unsolder the stripped end of the varactor diode next to the crystal socket, and solder the provided expander choke in series. |
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5. |
Cut resistor R187 to the right front of the circuit board. |
Alignment
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1. |
Turn the unit on and place the expander switch in the normal position, the mode switch to AM, and the clarifier fully clockwise. Using a frequency counter while transmitting, adjust the trimmer capacitor next to the crystal socket to read +1 KHz above center frequency. |
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2. |
The transformers Ll9 and L20 can be adjusted individually for AM and SSB frequency correction as well as the trimmers on the expander board. |
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3. |
Power and modulation adjustments are shown in Figure D. |
Summary
The unit will now extend far above and below its normal operating range, as well as slide and track with the clarifier control. A slight adjustment of the VCO may be necessary if the unit drops out before reaching its maximum channels.
NOTE: If trouble is encountered bringing the normal crystal on frequency add a 39 pf capacitor in series with one of the expander wires and realign.
EXPO 100 EXPANDER
MODEL K
AM Power = VR6 SSB Power = VR7 Modulation = Cut TR32
Note: Additional frequencies can be added by changing the MB8734 PLL Chip to a MB8719 and adding a SPST switch between pin 10 and ground.
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WARNING! This unit is Not Legal For Class D CB Use In The U.S.A.