Shively Labs FM Antennas and Accessories
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Typical Data for
Model 6814 FM Antenna (half-wave-spaced)

True Circular Polarization

Handles 25 kW per Bay

Multiplexes over 6 MHz Bandwidth

Shively Standard Features:

  • Ring Stub Design
  • Consistently Predictable Patterns
  • Low Weight and Windload
  • 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 ± 200 kHz for a single-frequency antenna.
1.1 : 1 over ± 200 KHzfor a dual frequency antenna with up to 6 MHz frequency separation.
Azimuth Pattern Circularity:
Horizontal component ±1.5 dB on pole.
Input Connection:
Female 4-1/16 in flange, except for 1-bay antenna: 3-1/8 in EIA.

Electrical Specifications (half-wave-spaced):

1.62 2.08 80 14 4.35 6.39 80
No. of
Bays		 Gain
 Power
Rating
kW		 No. of
Bays		 Gain
 Power
Rating
kW
Power dB Power dB
1
Not available
7
2.22
3.47
80
2
0.70
-1.54
50
8
2.53
4.03
80
3
1.01
1.05
75
10
3.14
4.96
80
4
1.31
1.17
80
12
3.75
5.24
80
5
1.62
2.08
80
14
4.35
6.39
80
6
1.92
2.83
80
16
4.96
6.96
80

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):
No. of Bays Vertical Tower Space
 Weight
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
228
1017
368
1641
901
4018
3
10
3.3
19
6.2
30
9.8
320
1427
530
2364
1348
6012
4
15
4.9
24
7.9
35
11.5
412
1838
692
3086
1795
8006
5
20
6.6
29
9.5
40
13.1
504
2248
854
3809
2243
10004
6
25
8.2
34
11.2
45
14.8
597
2663
1017
4536
2690
11997
7
30
9.8
39
12.8
50
16.4
689
3073
1179
5258
3136
13987
8
35
11.5
38
12.5
55
18.0
772
3443
1332
5941
3553
15846
10
45
14.8
48
15.7
65
21.3
935
4170
1635
7292
4412
19678
12
55
18.0
58
19.0
75
24.6
1120
4995
1960
8742
5306
23665
14
65
21.3
68
22.3
85
27.9
1304
5816
2284
10187
6200
27652
16
75
24.6
78
25.6
95
31.2
1488
6636
2608
11632
7095
31644

Windload (half-wave-spaced):
No. of
Bays		 Revision "C"
 Revision "F"
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
284
1267
1103
4919
1166
5200
9.2
0.9
28.5
2.6
30.5
2.8
3
454
2025
1684
7511
1786
7966
14.8
1.4
43.8
4.1
47.1
4.4
4
625
2788
2265
10102
2406
10731
20.5
1.9
59.0
5.5
63.7
5.9
5
796
3550
2845
12689
3025
13492
26.1
2.4
74.4
6.9
80.2
7.5
6
965
4304
3426
15280
3645
16257
31.8
3.0
89.6
8.3
96.8
9.0
7
1136
5067
4007
17871
4265
19022
37.4
3.5
104.9
9.7
113.3
10.5
8
1285
5731
4565
20360
4856
21658
42.3
3.9
119.4
11.1
128.9
12.0
10
1569
6998
5670
25288
6026
26876
52.3
4.9
148.7
13.8
160.4
14.9
12
1911
8523
6831
30466
7264
32397
63.6
5.9
179.3
16.7
193.5
18.0
14
2252
10044
7993
35469
8503
37923
74.9
7.0
209.9
19.5
226.6
21.1
16
2593
11565
9153
40822
9704
43280
86.2
8.0
240.5
22.3
259.8
24.1

Notes:

  1. The mounting structure must not flex more than ± 1/2 in (1.2 cm) in any ten-foot (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 ft (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. Windload and weight 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: 01/30/2007
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