If only Holmes and Lev had read the Television books before writing the RF Alignment engineering note for the RC-199 (RR-359A main chassis) dated June 22, 1936
The RC-199 (RR-359A) was 2.25Mhz spacing, the initial change to RC-199B (RR-359B) was 3.25MHz, the final modifications to RC-199B was 4.5MHz.