I am looking for a Texscan sweep generator manual please

I have a Texscan VS-20 sweep generator but any Texscan sweep generator manual will do, such as the VS-80 cause they share the same operating principles. 

Service or operators manual, whatever you have please share, I've been searching and there seems to be nothing out there. 

Thanks in advance and thanks ElektroTanya for providing us with valuable information, you've done great service to our hobby and profession!