Conar Model 221 223 224 Tube Test Data Book 1978 Version $9.99 Category: Conar Description Description For sale is reprint of Conar Tube Tester Model 221, 223, 224 Tube Test Data Book. Manual is 31 pages long dated January 1st 1978. Test data was released by Coletronics Service and is newest data for Conar tube testers. Related products Conar Model 230 Signal Tracer Assembly Operating Manual $9.99 Read more Conar Model 311 R-C Tester Assembly Operating Manual $9.99 Read more