K5GO Half-elements for 23rd and 24th Editions of ARRL Antenna Book
Chapter 25, Figures 25.10 and 25.11

Wind/ice survivability ratings in mph:

Heavy Duty (LD) Elements
 
Band    Wind Speed    With 1/2" ice    With 1" inch ice
 
40        118              78                 42
30        115              76                 35
20        127              81                 47
17        142              89                 60
15        135              79                 44
12        145              79                 45
10        162              96                 67
 6        172              92                 62
 
Light Duty (LD) Elements
 
Band    Wind Speed    With 1/2" ice    
 
40        82               45                    
30        89               46                    
20        90               46                    
17        85               37                    
15        95               50                    
12        99               50                    
10        101              48                    
 6        145              77                    
  
Every light duty element fails with 3/4" of radial ice except for the 6 meter element. If you live in an area that occasionally gets ice of any significance, you would be wise to use the heavy-duty (HD) elements.  Ice-phobic paint is available from Wearlon Industries (www.wearlon.com).  That, in combination with element trussing will reduce the chance of failure due to severe ice loading. 
 
All tubing with 0.116" wall thickness consists of concentric 0.058" wall sections of the same length.  i.e. - a 0.750" OD segment with 0.116" wall thickness is constructed from  0.750" OD tubing of 0.058" wall thickness with the same length of 0.625" OD tubing with 0.058" wall thickness inside it.

Tubing on the 40 meter LD and HD elements with 0.125" or 0.250" wall thickness is T6061-6 alloy.  All other tubing is 6063-T832.

- - - - - - - - - - - - - - - -

Each half-element is defined as follows:

Band and Light Duty/Heavy Duty (LD/HD)
Total half-element length (inches)
Center to Tip order
Section label
Total length of tubing section (inches)
OD of tubing (inches)
Tubing wall thickness (inches)

Notations:
  EX - Total exposed length
  OL - Overlap with next larger section
  DB - Doubler: tubing section completely inside and flush with the inner end of next larger section

- - - - - - - - - - - - - - - -
Light-duty half-elements
- - - - - - - - - - - - - - - -

6LD: 
Total half-element length: 36+22 = 58
Center	Tip
Sect 2	Sect 1
36	26
0.500	0.375
0.058	0.058
36 EX	
	4 OL
	22 EX	
		
10LD: 
Total half-element length: 36+32+38 = 106
Center		Tip
Sect 3	Sect 2	Sect 1
36	36	42
0.625	0.500	0.375
0.058	0.058	0.058
36 EX	
	4 OL
	32 EX	
		4 OL
		38 EX

12LD:
Total half-element length: 36+32+32+28 = 128
Center			Tip
Sect 4	Sect 3	Sect 2	Sect 1
36	36	36	32
0.750	0.625	0.500	0.375
0.058	0.058	0.058	0.058
36 EX
	4 OL
	32 EX	
		4 OL
		32 EX	
			4 OL
			28 EX

15LD:
Total half-element length: 36+32+32+32+10 = 142
Center				Tip
Sect 5	Sect 4	Sect 3	Sect 2	Sect 1
36	36	36	36	14
0.875	0.750	0.625	0.500	0.375
0.058	0.058	0.058	0.058	0.058
36 EX
	4 OL
	32 EX
		4 OL
		32 EX
			4 OL
			32 EX
				4 OL
				10 EX

17LD:
Total half-element length:36+33+33+33+30 = 165
Center				Tip
Sect 5	Sect 4	Sect 3	Sect 2	Sect 1
36	36	36	36	36
0.875	0.750	0.625	0.500	0.375
0.058	0.058	0.058	0.058	0.058
36 EX
	3 OL
	33 EX
		3 OL
		33 EX
			3 OL
			33 EX
				6 OL
				30 EX

20LD:
Total half-element length: 36+33+15+15+21+24+33+47 = 224
Center							Tip
Sect 8	Sect 7	Sect 6	Sect 5	Sect 4	Sect 3	Sect 2	Sect 1
36	36	18	18	24	27	36	50
1.250	1.125	1.000	0.875	0.750	0.625	0.500	0.375
0.058	0.058	0.058	0.058	0.058	0.058	0.058	0.058
36 EX
	3 OL
	33 EX
		3 OL
		15 EX
			3 OL
			15 EX
				3 OL
				21 EX
					3 OL
					24 EX
						3 OL
						33 EX
							3 OL
							47 EX

30LD:
Total half-element length: 36+68+68+68+32+32 = 304
Center					Tip
Sect 6	Sect 5	Sect 4	Sect 3	Sect 2	Sect 1
36	72	72	72	36	36
1.500	1.250	1.000	0.750	0.500	0.375
0.116	0.116	0.116	0.116	0.058	0.058
36 EX
	4 OL
	68 EX
		4 OL
		68 EX
			4 OL
			68 EX
				4 OL
				32 EX
					4 OL
					32 EX

40LD:
Total half-element length: 144+66+68+68+20+20+20+32 = 438
Center									Tip
Sect 10	Sect 9	Sect 8	Sect 7	Sect 6	Sect 5	Sect 4	Sect 3	Sect 2	Sect 1
144	72	36	72	36	72	24	24	24	36
2.000	1.500	1.250	1.250	1.000	1.000	0.750	0.625	0.500	0.375
0.125	0.116	0.058	0.116	0.058	0.116	0.058	0.058	0.058	0.058
144 EX
	6" reducing sleeve required
	6 OL
	66 EX
		36 DB
			4 OL
			68 EX
				36 DB
					4 OL
					68 EX
						4 OL
						20 EX
							4 OL
							20 EX
								4 OL
								20 EX
									4 OL
									32 EX


- - - - - - - - - - - - - - - -
Heavy-Duty Half-elements
- - - - - - - - - - - - - - - -

6HD:
Total half-element length: 36+22 = 58
Center	Tip
Sect 2	Sect 1
36	26
0.500	0.375
0.116	0.058
36 EX
	4 OL
	22 EX

10HD:
Total half-element length: 36+32+20+20 = 108
Center			Tip
Sect 4	Sect 3	Sect 2	Sect 1
36	36	24	24
0.875	0.750	0.500	0.375
0.116	0.116	0.058	0.058
36 EX
	4 OL
	32 EX
		4 OL
		20 EX
			4 OL
			20 EX

12HD:
Total half-element length: 36+32+36+20 = 124
Center			Tip
Sect 4	Sect 3	Sect 2	Sect 1
36	36	72	24
0.875	0.625	0.500	0.375
0.116	0.058	0.058	0.058
36 EX
	4 OL
	32 EX
		36 OL
		36 EX
			4 OL
			20 EX
Note: Sect 2 and Sect 3 are doubled-up for the length of Sect 2

15HD:
Total half-element length: 36+68+32+6 = 142
Center			Tip
Sect 4	Sect 3	Sect 2	Sect 1
36	72	36	10
1.000	0.750	0.500	0.375
0.116	0.116	0.058	0.058
36 EX
	4 OL
	68 EX
		4 OL
		32 EX
			4 OL
			6 EX

17HD:
Total half-element length: 36+68+20+20+24 = 168
Center			Tip
Sect 5  Sect 4	Sect 3	Sect 2	Sect 1
36	72	24	24	28
1.250	1.000	0.750	0.500	0.375
0.116	0.116	0.116	0.058	0.058
36 EX
	4 OL
	68 EX
		4 OL
		20 EX
			4 OL
			20 EX
				4 OL
				24 EX

20HD:
Total half-element length: 36+68+32+20+20+20+28 = 224
Center						Tip
Sect 7	Sect 6	Sect 5	Sect 4	Sect 3	Sect 2	Sect 1
36	72	36	24	24	24	28
1.500	1.250	1.000	0.750	0.625	0.500	0.375
0.116	0.116	0.116	0.058	0.058	0.058	0.058
36 EX
	4 OL
	68 EX
		4 OL
		32 EX
			4 OL
			20 EX
				4 OL
				20 EX
					4 OL
					20 EX
						4 OL
						28 EX

30HD:
Total half-element length: 36+68+32+32+32+32+20+20+32 = 304
Center								Tip
Sect 9  Sect 8	Sect 7	Sect 6	Sect 5	Sect 4	Sect 3	Sect 2	Sect 1
36	72	36	36	36	36	24	24	36
2.000	1.750	1.500	1.250	1.000	0.875	0.750	0.500	0.375
0.116	0.116	0.116	0.116	0.116	0.058	0.058	0.058	0.058
36 EX
	4 OL
	68 EX
		4 OL
		32 EX
			4 OL
			32 EX
				4 OL
				32 EX
					4 OL
					32 EX
						4 OL
						20 EX
							4 OL
							20 EX
								4 OL
								32 EX


40HD:
Total half-element length: 144+40+28+32+68+32+20+20+20+36 = 440
Center									Tip
Sect 10	Sect 9	Sect 8	Sect 7	Sect 6	Sect 5	Sect 4	Sect 3	Sect 2	Sect 
144	48	36	36	72	36	24	24	24	40
3.000	2.000	1.750	1.500	1.250	1.000	0.750	0.625	0.500	0.375
0.125	0.116	0.116	0.116	0.116	0.116	0.058	0.058	0.058	0.058
144 EX
	See note
	8 OL
	40 EX
		8 OL
		28 EX
			4 OL
			32 EX
				4 OL
				68 EX
					4 OL
					32 EX
						4 OL
						20 EX
							4 OL
							20 EX
								4 OL
								20 EX
									4 OL
									36 EX

Note: The overlap from Sect 10 to Sect 9 requires two "donut" reducing adapters. 
Use a short piece of 2.75 OD x .500 wall tubing to machine the adapters.  Each
adapter should 2" long, slightly less than 2.75 OD and slightly larger than 2"
ID (approx. 0.010" clearance required).  Place one at the inner edge of Sect 9
and the other at the outer edge of Sect 10.

