Shively Labs FM Antennas and Accessories
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Typical Data for
Model 6814 FM Antenna (full-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 (full-wave-spaced):
No. of
Bays		 Gain
 Power
Rating
kW		 No. of
Bays		 Gain
 Power
Rating
kW
Power dB Power dB
1
0.46
-3.40
25
7
3.87
5.88
80
2
0.99
-0.04
50
8
4.46
6.50
80
3
1.55
1.90
75
10
5.65
7.52
80
4
2.12
3.26
80
12
6.85
8.36
80
5
2.70
4.31
80
14
8.05
9.06
80
6
3.28
5.16
80
16
9.25
9.66
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 (full-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
1
2
0.7
9
3.0
20
6.6
156
696
226
1008
489
2181
2
10
3.3
19
6.2
30
9.8
249
1111
389
1735
936
4175
3
20
6.6
29
9.5
40
13.1
341
1521
551
2457
1383
6168
4
30
9.8
39
12.8
50
16.4
433
1931
713
3180
1830
8162
5
40
13.1
49
16.1
60
19.7
525
2342
875
3903
2278
10160
6
50
16.4
59
19.4
70
23.0
618
2756
1038
4629
2725
12154
7
60
19.7
69
22.6
80
26.2
710
3167
1200
5352
3171
14143
8
70
23.0
73
23.9
90
29.5
793
3537
1353
6034
3588
16002
10
90
29.5
93
30.5
110
36.1
977
4357
1677
7479
4482
19990
12
110
36.1
113
37.1
130
42.6
1162
5183
2002
8929
5376
23977
14
130
42.6
133
43.6
150
49.2
1346
6003
2326
10374
6270
27964
16
150
49.2
153
50.2
170
55.8
1530
6824
2650
11819
7165
31956

Windload (full-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
1
169
754
579
2582
617
2752
4.5
0.4
14.2
1.3
15.0
1.4
2
340
1516
1159
5169
1236
5513
10.6
1.0
29.9
2.8
32.2
3.0
3
510
2275
1740
7760
1856
8278
16.2
1.5
45.2
4.2
48.8
4.5
4
681
3037
2321
10352
2476
11043
21.9
2.0
60.4
5.6
65.4
6.1
5
852
3800
2901
12938
3095
13804
27.5
2.6
75.8
7.0
81.9
7.6
6
1021
4554
3482
15530
3715
16569
33.2
3.1
91.0
8.5
98.5
9.2
7
1192
5316
4063
18121
4335
19334
38.8
3.6
106.3
9.9
115.0
10.7
8
1341
5981
4621
20610
4926
21970
43.7
4.1
120.8
11.2
130.6
12.1
10
1681
7497
5782
25788
6166
27500
55.0
5.1
151.4
14.1
163.8
15.2
12
2023
9023
6943
30966
7404
33022
66.3
6.2
182.0
16.9
196.9
18.3
14
2364
10543
8105
36148
8643
38548
77.6
7.2
212.6
19.8
230.0
21.4
16
2705
12064
9265
41322
9884
44083
88.9
8.3
243.2
22.6
263.2
24.5

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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