## Saturday, November 16, 2019

### TI-84 Plus CE: Bucket Curve Analysis

TI-84 Plus CE:  Bucket Curve Analysis

Introduction

The program, originally presented by David Burch in the April & May 1985 edition of Datafile (see source below), calculates radio-only noise (dB) and system noise (dB) give the following variables:

*  Tangential Idel noise
*  Second-order Intermodulation
*  High-order Intermodulation

The program, which Burch originally did for the HP 41C, eliminates the need for radio-only and echo noise nomographs.

The program, ported for the TI-84 Plus here first solves for radio-only noise (P_S) by solving the equation for P_I by repeated iteration:

I = I - 10 log (1 + 10^((I-M)/10)

After each iteration, H is stored to M and H zeroes out.  Radio-only noise is solved when M = 0.   At that point, P_S = M.

where:
I:  intial idle noise (dB)
M:  second-order intermodulation
H:  high-order intermodulation

The next step is calculate system echo noise (P_D):

N = N - 10 log (1 - 10^((N-S)/10)

The initial value of S is P_S.

Iteration happens again until N = 0,which at that point, P_D = N.

TI-84 PLUS Program: BUCKET

ClrHome
Disp "BUCKET CURVE ANALYSIS"
"DAVID BURCH 1985"
Input "IDLE LINE? ",I
Input "I.MOD LINE? ",M
Input "HIGH I.MOD? ",H
1→F
Lbl 1
I-10*log(1+F*10^((I-M)/10))→I
H→M
0→H
If M≠0
Goto 1
If F=­1
Goto 2
I→R
I→M
Input "MEASURED NOISE? ",I
­1→F
Goto 1
Lbl 2
Disp "SYSTEM ECHO:",I
I→S

Example

Idle Line?  44.5
I.Mod Line?  52
High I.Mod?  56
Result:  R Noise ≈ 43.536

Measured Noise? 40
Result:  System Echo ≈ 42.542

Source

Burch, David "Bucket Curve Analysis"  Datafile April & May 1985.  Vol. 4.  No. 3

Eddie

All original content copyright, © 2011-2019.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.

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