Shively Labs FM Antennas and Accessories
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Typical Data for
Model 6810 FM Antenna (half-wave-spaced)

  • True Circular Polarization
  • Power Rating: 10 kW per Bay
  • Best Sidemount in the Industry for Directionals
  • Will Diplex over 2.4 MHz Bandwidth
  • Shively Standard Features:
    • Ring Stub Design
    • Consistently Predictable Patterns
    • Digital Ready
    • Pattern Studies Available
    • No Factory Personnel Needed to Install
    • Adjustable Fine-Matching Transformer
    • Radomes and Deicers Available
    • Rugged Corrosion-Resistant Mounts
    • Works with Regular Towers; No Need for Special Frequency-Sensitive Tower Sections
    • Pressure Relief Valve for Easy Purging of the System
    • Special Spacing, H/V Ratios, Null Fill and Beam Tilt Available

Performance Specifications:

Polarization:
Right circular.
VSWR:
1.05 : 1 ± 100 kHz
1.09 : 1 ± 200 kHz
1.06 : 1 ± 100 kHz for dual-frequency version
1.1 : 1 ± 200 kHz for dual-frequency version
Azimuth Pattern Circularity:
Horizontal component ±1.5 dB on pole.
Input Connection:
Female 3-1/8 in EIA.

Electrical Specifications (half-wave-spaced):

No. of
Bays		 Gain
 Power
Rating
kW		 No. of
Bays		 Gain
 Power
Rating
kW
Power dB Power dB
2
0.70
-1.54
20
8
2.53
4.03
40
3
1.01
1.05
30
10
3.14
4.96
40
4
1.31
1.17
40
12
3.75
5.74
40
5
1.62
2.08
40
14
4.35
6.39
40
6
1.92
2.83
40
16
4.96
6.96
40

Notes:

Our gain figures are derived from the computed directivity and include the losses in the antenna feed system.

Gain is provided for one polarization and is equal in circularly polarized antennas for both horizontal and vertical components. Gain will be reduced if null fill, beam tilt, special H/V ratio, or special wavelength spacing is provided. Gain will increase in a directional array by the directivity of the azimuth pattern.

Size and Weight (half-wave-spaced):

Vertical Tower Space
 Weight
No. of Bays Antenna radiation aperture
 Physical
space used
 Total tower space recommended
 without
radomes
 with
radomes
 with radomes &
1/2"radial ice
ft m ft m ft m lb N lb N lb N
2
5
1.6
14
4.6
25
8.2
177
789
247
1102
527
2350
3
10
3.3
19
6.2
30
9.8
235
1048
340
1516
771
3439
4
15
4.9
24
7.9
35
11.5
293
1307
433
1931
1015
4527
5
20
6.6
29
9.5
40
13.1
351
1565
526
2346
1259
5615
6
25
8.2
34
11.2
45
14.8
409
1824
619
2761
1503
6703
7
30
9.8
39
12.8
50
16.4
468
2087
713
3180
1747
7792
8
35
11.5
38
12.5
55
18.0
520
2319
800
3568
1966
8768
10
45
14.8
48
15.7
65
21.3
622
2774
972
4335
2429
10833
12
55
18.0
58
19.0
75
24.6
739
3296
1159
5169
2917
13010
14
65
21.3
68
22.3
85
27.9
855
3813
1345
5999
3405
15186
16
75
24.6
78
25.6
95
31.2
971
4331
1531
6828
3892
17358

Windload (half-wave-spaced):

Rev. "C"
 Rev. "F"
No. of Bays without
radomes
 with
radomes
 with radomes &
1/2"radial ice
 without
radomes
 with
radomes
 with radomes &
1/2"radial ice
lb N lb N lb N ft² m² ft² m² ft² m²
2
245
1093
485
2163
559
2493
8.2
0.8
13.8
1.3
16.1
1.5
3
385
1717
745
3323
862
3845
13.0
1.2
21.3
2.0
25.0
2.3
4
526
2346
1005
4482
1166
5400
17.7
1.6
28.9
2.7
34.0
3.2
5
666
2970
1265
5642
1469
6552
22.5
2.1
36.4
3.4
42.9
4.0
6
806
3595
1525
6802
1772
7903
27.3
2.5
44.0
4.1
51.8
4.8
7
947
4224
1786
7966
2075
9255
32.0
3.0
51.5
4.8
60.8
5.6
8
1069
4768
2028
9045
2355
10503
36.1
3.4
58.4
5.4
68.8
6.4
10
1307
5829
2505
11172
2905
12956
45.6
4.2
72.4
6.7
85.3
7.9
12
1588
7082
3025
13492
3511
15659
55.1
5.1
87.5
8.1
103.0
9.6
14
1868
8331
3546
15815
4118
18366
64.7
6.0
103.0
9.6
121.0
11.2
16
2149
8585
4066
18134
4725
21074
74.2
6.9
118.0
11.0
139.0
12.9

Notes:

  1. The mounting structure must not flex more than ± 1/2 in (± 1.2 cm) in any 10-ft (3-meter) section. Five feet (1.5 m) of mounting structure is required above and below the antenna bays for proper pattern formation.
  2. Antenna radiation aperture is the distance from the center of the top bay to the center of the bottom bay. Physical space used is from the top of the top bay to the input flange at the bottom of the array, or the bottom of the bottom bay in a center-fed array. Total tower space recommended allows ten feet (3 m) of clear tower space above and below the antenna to protect from pattern interference by other antennas. At frequencies lower than 98 MHz, each of these dimensions will increase by up to 1 foot (0.3 m) per bay.
  3. Seven bays or less are normally end-fed. All antennas supplied with beam tilt will be center-fed. Antennas with an odd number of bays are normally not available with center feed.
  4. Weight and windload tabulations are estimates and assume 98 MHz. They include the bay, interbay feedline, input connection, and a fine-matching transformer. No values have been included in these tabulations for mounts. Actual values vary with the specific installation. Contact us with details of your installation if more precise values are needed.
  5. Antenna windloads are calculated for 112 mph (180 kph), using 50 psf (2400 N/m²) for flats and 33 psf (1600 N/m²) for rounds] per EIA standard RS-222-C and CSA standard S37-94. The surface area is calculated per EIA standard RS-222-F (CaAc).
  6. Deicers add approximately 1 lb (4.4 N) per bay in weight and 2 lb (8.9 N) or 0.05 ft² (0.005 m²) per bay in windload.
  7. Ask for technical assistance at Shively if you are planning to mount antennas on AM towers or install them at altitudes over 3,000 ft (915 m) above mean sea level.
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Last updated: 10/09/2007
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