If you want LSB you need to fit an extra crystal to the RF,Mixer & Dual Synthesiser board.

The RF, Mixer & Dual Synthesiser board is located under the shorter lid and is on the left with the heatsink

away from you.

You then need to program the channels for LSB either via an EPROM change, or using P-Channels

Picture of the LSB Crystal Z3, 1647 khz Fitted to the RF, Mixer & Dual Synthesiser Board.

The trimmer next to it, C162 is used to adjust the frequency while holding the TUNE button in.

If there is not enough adjustment, C 161 (27p) can be changed. C161 is located between C162 and the stand -off post in the picture.