Try defining the parameters at the top of your query.
PARAMETERS [parExamFreq] Text ( 255 ), [parExamPeriod] Text ( 255 )
SELECT
tblEquipment.EquipmentID,
(
DatePart("yyyy", [tblEquipment].[StartOfServiceDate]) * 1000
) + DatePart("ww", [tblEquipment].[StartOfServiceDate])...