Hyperbolic Match Output

Number:23a

Maker:DING FENG (China)

Model:No. 5471 Duplex Vector

Scales Front: || 2D, L, K, A || Tan&Cot, Sin&Cos, H', CI, C || D, Th, Sh1, Sh2 || CF and DF are folded at √10

Scales Back: || LL01, LL02, LL03, DF || CF, CIF, H, CI, C || D, LL3, LL2, LL1||

Gauge Marks: Need information. Probably the same as 22.

Cursor Back:

Construction: 25 cm.; Plastic face on laminated wood; Cursor is framed.

Date: 1958

Source: PMH (Hopp Pg 161)and PVM and eBay and Xu Guisheng

Information:

Cursor Back: