Bill, There is also a tuning eye tube in back of xmtr , the Xtal and
tuning eye is used to calibrate the VFO .You won`t need the Xtal or eye
tube for ham use.. I used an Arc 5 about 60 years ago on 40 mtrs. I had
pretty good output BUT it chirped like all crazy..there were several
schemes to get the chirp out, none of them worked very well..If you can
get the VFO to key without chirping it will be all OK. Good luck 73
Harold W4PQW