Any HP-25c schematics?
09-01-2018, 04:17 AM
Post: #6
 Thomas Klemm Senior Member Posts: 1,854 Joined: Dec 2013
RE: Any HP-25c schematics?
(08-31-2018 07:53 PM)SlideRule Wrote:  Can be downloaded from archive.org as NTRS-1978002312 LORAN Time Difference.

Thanks for the link to the program.

These formulas are used:

\begin{align*} \beta_T&=\tan^{-1}[C\tan(\Phi_T) ] \\ \beta_R&=\tan^{-1}[C\tan(\Phi_R) ] \\ X &= \cos^{-1}[\sin(\beta_R)\sin(\beta_T)+\cos(\beta_R)\cos(\beta_T)\cos(\lambda_R-\lambda_T)] \end{align*}

But we can factor out $$\cos(\beta_R)\cos(\beta_T)$$ and get:

$$X = \cos^{-1}[\cos(\beta_R)\cos(\beta_T)(\tan(\beta_R)\tan(\beta_T)+\cos(\lambda_R-\lambda_T))]$$

Hence we can avoid calculating $$\sin(\beta_R)$$ and $$\sin(\beta_T)$$ since $$\tan(\beta_R)$$ and $$\tan(\beta_T)$$ have already been computed.

This makes the program a bit shorter:
Code:
01: 24 06    RCL 6          C 02: 24 01    RCL 1          Φ_T                 C 03: 14 06    f tan          tan(Φ_T)            C 04:    61    ×              C tan(Φ_T) = tan(β_T) 05:    31    ENTER          tan(β_T)            tan(β_T) 06: 15 06    g tan⁻¹        β_T                 tan(β_T) 07: 14 05    f cos          cos(β_T)            tan(β_T) 08: 24 06    RCL 6          C                   cos(β_T)            tan(β_T) 09: 24 03    RCL 3          Φ_R                 C                   cos(β_T)            tan(β_T) 10: 14 06    f tan          tan(Φ_R)            C                   cos(β_T)            tan(β_T) 11:    61    ×              C tan(Φ_R)          cos(β_T)            tan(β_T)            tan(β_T) 12:    31    ENTER          tan(β_R)            tan(β_R)            cos(β_T)            tan(β_T) 13:    22    R↓             tan(β_R)            cos(β_T)            tan(β_T)            tan(β_R) 14: 15 06    g tan⁻¹        β_R                 cos(β_T)            tan(β_T)            tan(β_R) 15: 14 05    f cos          cos(β_R)            cos(β_T)            tan(β_T)            tan(β_R) 16:    61    ×              cos(β_R)cos(β_T)    tan(β_T)            tan(β_R)            tan(β_R) 17:    22    R↓             tan(β_T)            tan(β_R)            tan(β_R)            cos(β_R)cos(β_T) 18:    61    ×              tan(β_R)tan(β_T)    tan(β_R)            cos(β_R)cos(β_T)    cos(β_R)cos(β_T) 19:    21    x<>y           tan(β_R)            tan(β_R)tan(β_T)    cos(β_R)cos(β_T)    cos(β_R)cos(β_T) 20:    22    R↓             tan(β_R)tan(β_T)    cos(β_R)cos(β_T)    cos(β_R)cos(β_T)    tan(β_R) 21: 24 04    RCL 4          λ_R                 tan(β_R)tan(β_T)    cos(β_R)cos(β_T)    cos(β_R)cos(β_T) 22: 24 02    RCL 2          λ_T                 λ_R                 tan(β_R)tan(β_T)    cos(β_R)cos(β_T) 23:    41    -              λ_R-λ_T             tan(β_R)tan(β_T)    cos(β_R)cos(β_T) 24: 14 05    f cos          cos(λ_R-λ_T)        tan(β_R)tan(β_T)    cos(β_R)cos(β_T) 25:    51    +              tan(β_R)tan(β_T)+cos(λ_R-λ_T)           cos(β_R)cos(β_T) 26:    61    x              cos(β_R)cos(β_T)(tan(β_R)tan(β_T)+cos(λ_R-λ_T)) = cos(X) 27: 15 05    g cos⁻¹        X 28: 24 05    RCL 5          A(rad)  X 29:    61    ×              d = AX 30:    74    R/S            d 31: 24 00    RCL 0          T_m   T_s 32:    41    -              T_s-T_m

Example

21282.339
π
×
180
÷
STO 5

0.99664767
STO 6

39.1930
→H
STO 3

82.0615
→H
STO 4

34.034604
→H
STO 1

77.544676
→H
STO 2

f CLEAR PRGM
R/S

2317.7679

Cheers
Thomas
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 Messages In This Thread Any HP-25c schematics? - Archilog - 08-31-2018, 01:14 PM RE: Any HP-25c schematics? - Leviset - 08-31-2018, 01:53 PM RE: Any HP-25c schematics? - SlideRule - 08-31-2018, 07:53 PM RE: Any HP-25c schematics? - [kby] - 06-17-2019, 06:14 PM RE: Any HP-25c schematics? - Archilog - 08-31-2018, 03:08 PM RE: Any HP-25c schematics? - AndiGer - 08-31-2018, 05:21 PM RE: Any HP-25c schematics? - Thomas Klemm - 09-01-2018 04:17 AM RE: Any HP-25c schematics? - AndiGer - 06-17-2019, 06:40 PM RE: Any HP-25c schematics? - [kby] - 06-17-2019, 07:12 PM

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