The results of an ECOM program t o develop quartz c r y s t a l units and a s u i t a b l e VCXO c i r c u i t f o r a high s t a b i l i t y remote sensor t r a n s m i t t e r are reviewed. A d e s c r i p t i o n will be given of the techniques and processes developed t o p r o d c e 20-22 MHz crystal. units wlth a frequency deviation of 3 p m over the temperature range 0 t o @C, s p e c i f i c C, values, low aging and capable of withstanding lOOOg, U. millisecond shocks. The acivantages o f u s i n g e l e c t r o p l a t e d n i c k e l films f o r bondi n g this and other types o f c w s t d l units are discusmd. Q u a r t z c r y s t a l . o s c i l l a t o r c i r c u i t c h a r a c t e r i s t i c s are reviewed from the standpoint of achieving 8 2 5 ppn overall center frequency tolerance for a 20-22 MHz VCXO under a v i d e range of operating conditions 5nclucKng channel s e l e c t i o n by crystal unit replacement and the inacknissibility of tempeTature control. A crystal o s c i l l a t o r c i r c u i t i s described which is capable of a frequency tmperature s t a b i l i t y better than + & ppn over a o t o W C range w h i l e m a i n t a i n i n g e s s e n t i a frequency deviation and l i n e a r i t y .