Original Mast layouts for the different SAL-XX Mark II models, made with constant diameter of 1-1/2" (38.1 mm) OD and 1-3/8" (34.93 mm)) coupling inserts. The base section is double thickness wall (0.116" or 2.95 mm) the rest is 0.058" or 1.47 mm wall thickness. Bottom of first section above the mast has a riveted 6" (152.4 mm) insert to have the same ID of the base section in order to insert the 1-1/4" (31.75 mm) OD insulator.
Given the broadband nature of the SAL antenna you can change the measurements within reasonable tolerances +/- 6" (+/- 15 cm) and it will not affect performance at all. It is very important to keep symmetry within practical limits.
Mast guidelines for the SAL-30 Mark II
SAL-30 Mark II Mast proposal for imperial measurements with 12 feet long sections of aluminum tubing.
Using 12 foot long aluminum tubing sections. IMPORTANT: In order to make telescoping sections the wall thickness must be 0.058 inches or 58 mil.
One 1-1/2" x 12' x 0.058" wall: Cut in two pieces, one 4 feet long for the base and the other 8 feet long for the first section above the insulator.
One 1-3/8" x 12' x 0.058" wall: This section will go above the 8 ft x 1-1/2" section, inserted one foot, for a total of 11 feet exposed.
One 1-1/4" x 12' x 0.058" wall: This section will go above the 1-3/8" section, inserted one foot, for a total of 11 feet exposed.
SAL-30 Mark II Mast proposal for metric (International System) with 6.05 meter long sections of aluminum tubing.
Note: Notation is (OD x ID) x L = (Outer Diameter in mm x Inner Diameter in mm ) x Length in m
One (35 mm x 31 mm)x 6.05 m: Cut in two pieces, one 1.20 m for the base section and the other 4.85 m long for the first section above the insulator.
One (30 mm x 27 mm) x 6.05 m: This section needs only 4.29 m exposed to complete the 9.14 m needed above the insulator. You may want to cut it down to 4.60 m to insert about 30 cm into the lower 35 mm x 31 mm section.
Mast guidelines for the SAL-20 Mark II
SAL-20 Mark II Mast proposal for imperial measurements with 12 feet long sections of aluminum tubing.
Using 12 foot long aluminum tubing sections. IMPORTANT: In order to make telescoping sections the wall thickness must be 0.058 inches or 58 mil.
One 1-1/4" x 12' x 0.058" wall: Cut in two pieces, one 4 feet long for the base and the other 8 feet long for the first section above the insulator.
One 1-1/8" x 12' x 0.058" wall: This section will go above the 8 ft x 1-1/4" section, insert two feet, for a total of 10 feet exposed.
SAL-20 Mark II Mast proposal for metric (International System) with 6.05 meter long sections of aluminum tubing.
Note: Notation is (OD x ID) x L = (Outer Diameter in mm x Inner Diameter in mm ) x Length in m
One (35 mm x 31 mm)x 6.05 m: Cut in two pieces, one 1.20 m for the base section and the other 4.85 m long for the first section above the insulator.
One (30 mm x 27 mm) x 0.75 m: This section needs only 0.64 m exposed to complete the 5.49 m needed above the insulator. You may want to cut it down to 4.60 m to insert about 30 cm into the lower section.
Mast guidelines for the SAL-12 Mark II
SAL-12 Mark II Mast proposal for imperial measurements with 12 feet long sections of aluminum tubing.
Using one 12 ft and one 4 ft aluminum tubing sections.
One 1" to 1-1/4" x 4' x 0.058" wall for the base section.
One 1" to 1-1/4" x 12' x 0.058" wall for the section above the insulator.
SAL-12 Mark II Mast proposal for metric (International System) with 6.05 meter long sections of aluminum tubing.
Note: Notation is (OD x ID) x L = (Outer Diameter in mm x Inner Diameter in mm ) x Length in m
One (25 mm x 21 mm or 30 mm x 22 mm)x 6.05 m: Cut off two pieces, one 1.20 m for the base section and the other 3.66 m long for the section above the insulator.
Insulator
The insulator piece should be at least 7 inches (178 mm) long. Best would be fiberglass. White PVC can be used, maybe nesting smaller diameter PVC sections inside for reinforcement, wooden dowels could be used for this purpose as well. Keep in mind that PVC diameter refers to Inner Diameter (ID). The original design of our mast has 2" (50.8 mm) exposed. It can be less, given that there is no high voltage circulating on the antenna.
NOTE FOR OLD SAL MODEL UPGRADE: If you start the aluminum with a 1-3/4” OD x
0.058” wall tubing, the old model's fiberglass mast pipe top coupling will fit nicely inside
the aluminum tubing, that will let you use the fiberglass pole as the bottom
section to avoid the need of an insulator if a metal bottom section is used.
Tips and Disclaimer
NOTE 1: Depending of the minimum height desired for the antenna you might want to make the base section longer in order to avoid problems with vehicles, animals and people. Modify these suggestions at you convenience. The SAL antenna can be raised to improve the pattern, being the optimal height 1/4 wave length for a given frequency. If for shipping or transportation limitations you have to use shorter sections you will need to use a wider span of telescoping diameters for your mast. When selecting the sections diameters for the SAL-30 Mark II try to keep the top section with a minimum of 1-1/8" (or 28 mm for the metric dimensions version). You may need to select the bottom sections diameters depending on the sizes available for the insulator material.
NOTE 2: These are only suggestions or guidelines to make your own mast.Do it at your own risk and your own selection of materials. Array Solutions will be not responsible for any accident, malfunction or problem caused by your own design and construction of the mast. Remember you can be killed if the mast or any part of the antenna becomes close to high voltage power lines.
