20-meter Portable, Rotatable Dipole Antenna
by Rob L. Dey  KA2BEO
7/29/96, 6/11/97


2) 102"L (103") stainless steel whip with 3/8"-24 stud. RS #21-903 $14.99
        or 102"L (103") fiberglass whip with 3/8"-24 stud. RS #21-905 $14.99
        or 48"L fiberglass whip with 3/8"-24 stud. RS #21-934 $12.99
2) 24"L (23" actual) fiberglass marine cellular antenna extender with 1"-14
        (0.98"OD) ends for ORA #CMR1175, CMR1180, CMS1182, and CMS1183.
        This is to be used as a loading coil form that must be wound with #16
        or #14 AWG copper wire to specs per desired band. Also, drill and tap
        a #6-32 hole in each end for coil connection.
        Surplus from All Electronics #MAX-1 $4.00
        Insulator: 0.92"OD to 0.82"OD taper over 19"L (0.875"OD average).
        For 20-meters (14.100 MHz), a 3.5uH base loading coil is needed for
        each 103" whip.
        Use 43-turns (actual), not 60-turns (calculated) of #16 AWG insulated
        wire on each form.
	Use no loading coils for the 10-meter band.
4) 3/8"L, #6-32 S/S or brass machine screw. 1/2"L max. Crown Bolt, Inc. #32821
        HD $0.13
4) #6 S/S or brass lock washer. Crown Bolt, Inc. #32581 HD $0.06
8) #6 S/S or brass flat washer. Crown Bolt, Inc. #32461 HD $0.06
2) 3/4"-14 NPT threaded brass end cap. Drill and tap a 3/8"-24 hole in top (or
        use a 3/8" clear hole with nut on back) and #6-32 hole in side.
        RHC $2.29 or Anderson-Barrows Metals Corp. #A868 HD $1.43
2) 1/4"L, #6-32 S/S or brass machine screw. 1/2"L max. Crown Bolt, Inc. #32821
        HD $0.13
2) #6 S/S or brass lock washer. Crown Bolt, Inc. #32581 HD $0.06
4) #6 S/S or brass flat washer. Crown Bolt, Inc. #32461 HD $0.06
1) 3"L, 3/4"-14 NPT threaded PVC coupler (nipple). (6"L $0.95)
1) 1-1/2"pipe S/S U-bolt with spacer (1/4"thk x 3-1/2"L x 2-3/16"centers). TVH
        (zinc-plated) Crown Bolt, Inc. #310 HD $0.95
1) 1-1/2"pipe heavy duty steel muffler clamp GM-style 3/8" U-bolt with saddle.
        Nickson Industries, Inc. #80 $1.00
	Only the saddle part is needed, and used with the U-bolt listed above.
2) 1/4"ID S/S flat washer. HD
1) 16' 5"L telescopic extension pole for mast (6'3" collapsed).
        HD #014746581402 $19.98
2) Small bungee cords to support mast.


20-meters (14.100MHz) = 21.75'L @ 65.5% of full size: 33.1915'L, Xl=300-ohms,
        L=3.5uH.
10-meters (27.262MHz) = 17.75'L


Results:

SWR: 1.75:1 @ 14MHz