Precision Model 220 Marker Adder Manual $8.99 Category: Precision Apparatus Company Description Description For sale is reprint of Precision Model 220 Marker Adder Manual. Manual is 10 pages long, Dated 1956. Sections include: Introduction, Circuit Description, Operation, Service Notes, Etc. Manual includes schematic. Related products Precision Tube Tester Model 660 Operating Instructions with Tube DataOpens in a new window or tab $13.99 Read more Precision Tube Test Data for 910 912 914 915 920 922 254 Tube Testers $9.99 Read more Precision Apparatus EV-20 Vacuum Tube Multi-Meter Manual Read more 1967 Precision Supplementary Tube Test Data for 640 and 660 Tube Testers $9.99 Read more