Hi,
Welcome to the forum. I am not aware of a "crystal" close to the Lux sensor (under the white dome). Have you seen the photos near to the foot of Page 4 of
This Long Thread in the "Fine Offset" (who manufactured this range of stations) section of the forum?
Note that the "Solar Pod" cannot transmit a radio signal itself. Its RJ11 cable must be plugged into the appropriate Temp/Hum/Wind/Rain transmitter module, to receive power (maintaining timekeeping overnight) and for that to transmit a radio data packet.
EDIT: From
This Even Longer Linked Thread there appears to be a "watch crystal" on the underside of the board, which will be almost certainly 32.768 kHz (photo on page 7).
Cheers, Alan.