Clarifier Questions

[BigMike357]

Using the Cobra 2000 GTL Schematic how is the transmit side not able to change before unlocking the Clarifier? After unlocking what has changed in that allows it to
change the transmit frequency. Just curious.
Thanks Mike 35 Delta 357

 

[Xracerx13]

Before unlocking the clarifier, the 8v is removed during TX and restored during RX. Unlocking keeps the 8v there constantly for both TX and RX.

 

[doffo]

Just did the clarifier unlock on a Galaxy DX99v an hour ago. Did it right and just desoldered one side of the resistor and diode and pulled the leg through if ever one wishes to return it back to stock.

 

[BigMike357]

Before unlocking the clarifier, the 8v is removed during TX and restored during RX. Unlocking keeps the 8v there constantly for both TX and RX.

Thank you

 

[brandon7861]

R424 and R425 form a voltage divider powered by the RX supply rail. The fine control is paralleled with R424. The coarse and fine controls use this voltage for tuning the varactor during RX. During TX, the RX rail turns off and the high leg of VR5 is supplied via R188 from the TX rail. Since the RX rail is off, it is the job of D51 to prevent the TX supply from back feeding the RX supply rail. To make the clarifier controls work both TX and RX, either R188 or D52 needs to be clipped to cut off the TX power rail, and then the clarifier divider and the fine control pot need to be wired to the 8v source that stays on.

Below is a drawing of what I mentioned above and it should not require realignment of the radio. Lots of silly mods out there messing with R175, R44, adding diodes, etc that unnecessarily mess up the alignment.