alignment generators ?

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I restored a Heathkit IO-12 oscilloscope so I got that . I still have to get the demodulator probe and a crystal probe ,
Also restored 2 heathkit VTVM's .
I am supposed to be getting a photocopy of the manual . I read somewhere that it has a crystal in it , I think it plugs into to the front on the left .
there was a good website for heathkit test equipment . It is called Heathkit test equipment matrix . Their site is not working for some reason .
but it had all the info on these older heathkit testers .
Would this crystal be for the marker ?
Heathkit called this unit a alignment generator .
I dont know if it has the crystal with it or not but for 10 bucks , I cant loose .