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Figure 2

Typical Installation Phased (2) 18 HT 40 Meters

7200 KHz Design Frequency

SPECFICATIONS

Broadside

End Fire

Pattern width, half power points

60 degrees

80 degrees

Gain over single vertical

3.86 dB

2.3 dB

Side attenuation

30 dB

20 dB

Impedance

50 Ohms

50 Ohms

Directional characteristics

Bi-Directional

Bi-Directional

Summary of Contents for AV-18HT

Page 1: ...at an electrical 1 4 wavelength or odd multiple of 1 4 wavelength exists on all bands On 20 meters the 80 meter section acts as a 3 4 wave radiator The tilting base of the Hy Tower allows the antenna to be completely assembled on the ground before it is raised into position It is light enough for one person to assemble and for two people to erect Revision 3 AV 18HT Hy Tower Vertical Antenna 10 15 ...

Page 2: ...cable such as RG 213 U or RG 58A U Coaxial cable RG 213 U such as BELDEN 8267 is recommended for its lower line losses and higher power handling capabilities The SWR at resonance is less than 1 2 1 and will not exceed 3 5 1 over the entire range of each band Find a convenient location for the 18 HTS HyTower antenna It should be installed away from any power lines and should be at least 10 feet fro...

Page 3: ...e Three 3 1 1 4 compression clamps onto the pipe legs and position them near the insulators as shown in Figure 2 Tighten the clamps just enough to hold them in position Refer to Figure 5 for compression clamp instructions Install the 1 4 20 x 2 1 2 hex head bolts and nuts on the bottom of each base insulator assembly This bolt will help to anchor each leg in the concrete See Figure 2 Figure 2 Towe...

Page 4: ...he assembly so that the tower can hinge on base assembly A CAUTION The base assembly must be assembled level so that the tower will be vertical when it is installed Support the base assembly above the concrete in the manner shown in Figure 3 while the concrete is curing An easy method to ensure a level base involves using a low cost string level Loop a length of string through the three 3 holes on...

Page 5: ...d hardware Install the tower leg hinges and braces onto two tower legs as shown in Figure 4 Installation of Tubing Clamps Select the proper size tube clamp as shown in the chart See Figure 5B When installing the clamps place the clamp near the tube end with the top of the clamp over the slot in the tube as shown in Figure 5A After adjustment of the tubing lengths tighten the clamp with a 5 16 inch...

Page 6: ...6 7 16 1 2 all stainless steel 5 8 and 3 4 5 16 hex head screw Part Description Fits No Tubing Sizes 358757 Clamp Size 10 3 4 7 8 and 1 all stainless steel 5 16 hex head screw Part Description Fits No Tubing Sizes 358758 Clamp Size 16 1 11 8 all stainless steel and 11 4 5 16 hex head screw ...

Page 7: ... metal angles attached to the top tower section See Figure 6 Adjust the insulators so that they are ap proximately 28 3 8 apart with the bottom one approximately 1 1 2 from the end of the tubing the end with the metal sleeve Item Item No Description No Description 7 Angle vertical element 1 x 1 x 4 38 U Bolt 5 16 x 3 x 3 11 16 17 Insulator 2 I D x 3 7 8 39 Lockwasher split 5 16 stainless steel 26 ...

Page 8: ...5 8 x 48 piece of tubing and slip the unswaged end into the 7 8 tubing Measure 42 106 7 cm from the end of the 7 8 tube to the end of the 5 8 tube See Figure 7 Slip a 6 tubing clamp over the end of the 5 8 tubing Tighten slightly Select the 7 16 x 68 piece of tubing and slip it into the 5 8 tube Measure 66 167 6 cm from the end of the 5 8 tube to the end of the 7 16 tube See Figure 7 Slide the met...

Page 9: ......

Page 10: ...Figures 9 and 10 Install a leg clamp insulator and tubing clamp Install a leg clamp insulator and tubing clamp Select the 5 16 x 23 section of tubing and slip it into the 7 16 tuba Adjust to either Phone 19 or CW 21 1 4 dimension as shown in Figure 8 Install a compression clamp line up the screw with the hole on the 7 16 tube and tighten securely Select the 5 16 x 9 1 2 section of tubing and slip ...

Page 11: ...Figure 8 15 Meter Stub ...

Page 12: ......

Page 13: ...Measure 90 for both Phone and CW as shown in Figure 11 then tighten the compression clamp securely Select the 5 8 x 24 tube and install it on tower using two leg clamps and two shorting straps spaced 5 1 2 apart as shown in Figure 11 Slip a 6 tubing clamp onto the 5 8 tube Tighten slightly Place a 7 16 caplug on the top of the 40 meter stub NOTE The higher tubing clamp can be loosened and the lowe...

Page 14: ...Figure 11 40 Meter Stub ...

Page 15: ...e looped end at the top of the tower Select the 3 8 spacer tube and attach the 80 meter wire to the 2 tube as shown in Figure 12 Install the eyebolt at the tower base assembly as shown in Figure 12 Adjust for maximum height The 80 meter wire will attach to this eyebolt after the tower is tilted into place ...

Page 16: ...80 meters see Figure 12 it will be necessary to add a loading coil as previously explained and shown in Figure 13 This coil can be used to extend the 80 meter band or add 160 meter Figure 13 80 Meter and 160 Meter Coil Installation ...

Page 17: ...p of the tower as shown in Figure 17 This kit will provide a greater band width and a higher power rating than the LC 160Q It also provides fully automatic band switching from 160 through 10 meters Install the tower legs with hinges attached onto the base assembly Do not tighten screws at this time WARNING When installing your system take extreme care to avoid any accidental contact with power lin...

Page 18: ...ure 15 Weatherproof the coaxial cable using Coax Seal or some similar substance to prevent water from entering and ruining the coax The overall efficiency of the 18 HT S can be improved by adding a radial system The next section describes how to install a radial system Strip your coaxial cable and attach the center conductor to the tower base using the hole provided as shown in Figure 15 Attach th...

Page 19: ...meter of the circle to which the ground system extends the radials are sufficiently spread apart Most of the return currents are already in the ground between the radials rather than in the radials themselves As more radials are added the spaces between them are Since the 18 HT S Hy Tower is a multi band vertical antenna the radial system should be optimized on the lowest frequency you plan to use...

Page 20: ...s with a 1 4 wave radiating element 52 46 43 40 37 35 Radial end buried YES YES YES NO NO NO Table 1 Optimum Ground System Configuration NOTE TABLE 1 is optimized for poor earth conditions Conductivity 0 0001 Siemens meter and the Relative Dielectric Constant 7 Better earth conditions will increase the power gain and lower the take off angle for systems A D Systems E and F will not be affected as ...

Page 21: ...Figure 16 VSWR Charts ...

Page 22: ...Figure 17 Overall View of 18 HT S ...

Page 23: ... 2 1 2 stainless steel 1 22 561165 Flatwasher 10 stainless steel 3 23 565697 Lockwasher internal 10 stainless steel 15 24 554071 Nut hex 10 24 stainless steel 12 25 555693 Nut square 10 24 stainless steel 3 26 505266 Bolt hex head 1 4 20 x 3 4 stainless steel 5 27 502958 Bolt hex head 1 4 20 x 1 stainless steel 28 29 504098 Bolt hex head 1 4 20 x 1 stainless steel 21 30 505763 Bolt hex head 1 4 20...

Page 24: ...6 black 2 57 465416 Insulator decoupling stub 5 8 x 2 15 16 6 58 471056 Insulator Vertical Element Spacer l x 4 2 59 872451 Base Tube Assembly 3 60 872464 Wire Assembly 80 Meter 1 61 872465 Tube Assembly with dowel 2 x 75 1 62 874687 Tube Shim Assembly 2 x 51 1 63 882782 Base Assembly B 1 64 882783 Base Assembly A 1 Converting English Measurements to Metric 1 inch 1 2 54 cm Use this scale to ident...

Page 25: ...The Hy tower base assembly has been changed Substitute this drawing for figure 2 on page 3 ...

Page 26: ...en left out of the top section to allow for easy installment of the lower larger triangle Install two spacers between the triangle tab and the tower leg The upper plate should be installed with the triangle tabs on the outside of the tower legs Use the 1 4 20x 1 2 bolts for the upper small triangle Make sure that both of the triangles are oriented the same way ...

Page 27: ...required for the 24 feet high self supporting tower The top mast extends the height to 50 feet Two units make an ideal phased array MODEL 18AVT WB S The 18AVT WB S is a multi band trap vertical for 10 through 80 meters It is completely fac tory pre tuned and exhibits an extremely low angle DX radiation pattern It is easy to as semble light weight which one man can install A single 50 ohm coaxial f...

Page 28: ...nown for its low angle characteristics When you combine two identical verticals properly spaced and phased the resultant is a concentrated low angle of energy and a power gain These antennas can be so arranged to give a definite effect on either one or two favorite bands or all band coverage with some pattern compromise and slight loss of gain The following data was experimentally derived on the T...

Page 29: ...rrangements offer an excellent ad vantage over a single vertical since either phasing combination exhibits noticeable signal gain with side attenuation of undesired signals This added gain and low angle vertical directivity is the advantage of the phased array ENDFIRE GAIN 23 dB Phased verticals may be spaced either one quarter wave or one half wave depending upon gain and directional characterist...

Page 30: ...KHz Design Frequency SPECFICATIONS Broadside End Fire Pattern width half power points 60 degrees 80 degrees Gain over single vertical 3 86 dB 2 3 dB Side attenuation 30 dB 20 dB Impedance 50 Ohms 50 Ohms Directional characteristics Bi Directional Bi Directional ...

Page 31: ...s out of phase with a spacing of 1 4 wave length a cardioid pattern results This pattern may be switched in either direction By inserting a 1 4 wave length delay line the antenna will fire or be directive to that particular element TWO VERTICALS Figure 3 Cardioid Unidirectional With Two Selectable Directions ...

Page 32: ... pattern for two 1 4 wave length verticals will be approximately 120 degrees An arrangement of three switchable verticals gives a 60 degree pattern in six selectable directions Figure 4 360 Cardioid Arrangement ...

Page 33: ... Consideration must be given to the fact that 1 2 wave spacing optional is ideal for phasing When multi banding with close and wide spac ing compromise radiation patterns must be expected In most cases a choice spacing serves 3 bands most effectively with good directional characteristics added gain and low angle per formance ELECTRICAL SPECIFICATIONS VSWR Exceptionally low SWR is present with a ph...

Page 34: ...unications In cases where close and medium distance contacts are hampered by the array s low angle characteris tics and a higher angle is required switching arrangements can select one vertical for this coverage Low loss constant impedance type coaxial switches and connectors should be used when splicing phasing lines B W multi position single or multi gang coaxial switches with Am phenol coaxial ...

Page 35: ...ects Bi Directional patterns Use SW2 for broadside position 1 Endfire position 2 C All switches in position 2 selects cardioid pattern SW4 selects direction of cardioid pattern NOTE All connecting lines are exaggerated in length These lines must be direct and short as with any coax hook up prac tice Figure 5 Typical installation 2 18HT S Phased for 80 and 40 Meters Selectable Broadside and Endfire...

Page 36: ...Note Corralate Patterns to spacing used in installation Figure 6 Radiation Patterns Typical Spacing For Broadside And Endfire Arrangements ...

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