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from: ROB DENNIS
date: 1997-10-11 02:09:00
subject: LPAS Part 1

 Original article from: Wayne Sarosi 
 Reposted by Rob Dennis,Moderator HAM_TECH,for use of the FIDO HAM_TECH echo.
  THIS POST/SERIES NOT TO BE USED IN ANY CDROM COMPILATIONS FOR COMMERCIAL
 SALE WITHOUT EXPRESS WRITTEN PERMISSION OF ORIGINAL AUTHOR(S) OF THIS POST.
               ALL AND ANY COPYRIGHTS RETAINED BY AUTHOR(S).
SUBJECT:  LPA Series - 500 MHz to 1300 MHz
USE:  Amateur Bands 33cm & 23cm, directional scanning.
Note: See ARRL Antenna Handbook under LPA construction
Tau = 0.96
Sigma = 0.18
B = 2.6
COT alpha = 18
BAR = 1.32176
Bs = 3.436576
Lambda max = 1.968
Lb = [0.25(1-(1/Bs))COT alpha)Lambda max] = 6.3-ft
N = 1 + (log Bs / log (1/Tau)) = 31
The following are in inches, two of each required (L)
------------------------------
 L1 = 5.904               d1,2 = 4.248
 L2 = 5.668               d2,3 = 4.073
 L3 = 5.441               d3,4 = 3.915
 L4 = 5.223               d4,5 = 3.758
 L5 = 5.014               d5,6 = 3.608
 L6 = 4.813               d6,7 = 3.464
 L7 = 4.62                d7,8 = 3.325
 L8 = 4.435               d8,9 = 3.192
 L9 = 4.258              d9,10 = 3.064
L10 = 4.088             d10,11 = 2.941
L11 = 3.924             d11,12 = 2.823
L12 = 3.767             d12,13 = 2.71
L13 = 3.616             d13,14 = 2.6
L14 = 3.471             d14,15 = 2.496
L15 = 3.332             d15,16 = 2.3
L16 = 3.2               d16,17 = 2.208
L17 = 3.072             d17,18 = 2.12
L18 = 2.949             d18,19 = 2.035
L19 = 2.831             d19,20 = 1.954
L20 = 2.718             d20,21 = 1.876
L21 = 2.609             d21,22 = 1.8
L22 = 2.505             d22,23 = 1.728
L23 = 2.405             d23,24 = 1.659
L24 = 2.309             d24,25 = 1.593
L25 = 2.217             d25,26 = 1.53
L26 = 2.128             d26,27 = 1.469
L27 = 2.043             d27,28 = 1.41
L28 = 1.961             d28,29 = 1.35
L29 = 1.883             d29,30 = 1.296
L30 = 1.808             d30,31 = 1.244
L31 = 1.736
Zt =2.952  Sigma' = Sigma/sqrt Tau = 0.1837
Ro = 50
Zav = 302.56
Zo = Ro^2/(8(Sigma'(Zav))) + Ro(Sqrt(Ro/(8(Sigma'(Zav))) + 1) = 55.9
Gain = 10.5 dBi
S can be calculated from the ARRL Antenna Handbook.
Enjoy!  Next is the 67cm LPA!  The 500-1300 MHz LPA is currently under
construction at KB4YLY's QTH and will be in use in MARCH 93!
-WS
--- GoldED 2.42.G1219
---------------
* Origin: VE3SJN....Moderator....HAM_TECH (1:163/506.4)

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