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echo: ham_tech
to: ROB DENNIS
from: ROY WITT
date: 1997-11-01 10:56:00
subject: LPAS series

Hello Rob.
29 Oct 97 22:05, Rob Dennis wrote to Jeff Edmonson:
 RD>
 >>>  RD> ROY! Re-post please...
 >>> Ummmmmmmmmmm, now I wonder if Roy didn't netmailed me
 >>> that missing part.  CRS is taking its toll at this
 >>> age.
 JE>> Just saw it.  Let me know if you need it.
 RD>
 RD>  From the wrong series Jeff.
 RD>  The part I need is from the LPDA posting,part # 4.
LPDA or LPDS series?  I've got them all, just let me know which one it is 
that you need.  Antenna type and for what band..
=== Begin LPA4.ANT ===
Ä Ham (Amateur) Radio TECHnology Conference (1:202/909.10) ÄÄÄÄÄÄÄÄÄÄ 
HAM_TECH Msg  : #578 [26] From : Wayne Sarosi                        
1:374/73.2      21 Apr 97  20:12:01 To   : All                                
                 22 Apr 97  00:53:18 Subj : LPAs-4 
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ
Ä LPA Series - 141-149 MHz (2m + MARS/CAP)
USE:  Amateur Band 2m and MARS/CAP Frequencies
Note: See ARRL Antenna Handbook under LPA construction
Tau = 0.965
Sigma = 0.181
B = 1.0567
COT alpha = 20.686
BAR = 1.295
Bs = 1.368
Lambda max = 6.9787-ft
Lb = [0.25(1-(1/Bs))COT alpha)Lambda max] = 9.71-ft
N = 1 + (log Bs / log (1/Tau)) = 10
The following are in inches, two of each required (L)
-+----------------------------
 L1 = 21.84               d1,2 = 15.163
 L2 = 21.10               d2,3 = 14.632
 L3 = 20.40               d3,4 = 14.120
 L4 = 19.71               d4,5 = 13.626
 L5 = 19.06               d5,6 = 13.149
 L6 = 18.42               d6,7 = 12.689
 L7 = 17.81               d7,8 = 12.245
 L8 = 17.22               d8,9 = 11.816
 L9 = 16.65              d9,10 = 11.402
L10 = 16.09
Zt =10.468  Sigma' = Sigma/sqrt Tau = 0.18425
Ro = 50
Zav = 265.66
Zo = Ro^2/(8(Sigma'(Zav))) + Ro(Sqrt(Ro/(8(Sigma'(Zav))) + 1) = 57.0428
Gain = 10.5 dBi
S can be calculated from the ARRL Antenna Handbook, but is 0.804 for
0.25-in elements and 1-in booms.
Next is the 6m LPA.  Element attachment will be after the 6m
posting.  SEE BELOW!!!!
*************************************************************
*    NOTE: The boom on all these LPAs is 1-inch diameter.   *
*    All elements have a 0.9-in adjustment in the length    *
*    to compensate.  Sorry about that.  The Freq file will  *
*    have the proper statement put in.                      *
*************************************************************
-WS
---------------
* Origin: KB4YLY, Moderator (1:374/73.2)

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