A RIT Mod for the HW-8


D.A. "Mike" Michael, W3TS

Here is an effective RIT circuit which uses a minimum of parts and which can be assembled on a small piece of perf board and a small terminal strip.

Remove SW302 (wide/narrow filtering). If it is desired to retain this function, an SPDT miniature toggle switch may be installed in the upper right of the front panel near the preselector tuning capacitor. Otherwise, the rig may be wired permanently in the narrow position by disconnection the three wire cable between SW302 and the main PC board.

Jumper between points "HH" and "EE" on the board. Now mount the 1OK linear taper offset tuning pot on the hole left by SW302.

Drill a hole in both front panels to left of the new RIT control for SW1. This switch is either a normally closed push-button switch or a normally closed toggle switch with a monetary contact. It disables the RIT for zero beating the incoming signal.

Remove C55 (save it for latactuse), D11 and R36. Assemble all of the components to the left of the dashed line in the schematic on the perfboard and mount it on the inside wall near the zero beat switch, SW1. Use a small stand-off. Mount the remaining components on a small terminal strip and fasten the strip to the frame of the VFO tuning capacitor.

With the RIT offset tuning pot set at mid-range, adjust the 10K trim pot to set the desired shift on either the high or low side of zero beat. The pitch should not change with SW1 open or closed.

Click Here to see the schematic/diagram of this mod.

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