Shively Labs FM Antennas and Accessories
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Typical Data for
Model 6810 FM Antenna (full-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:
1.06 : 1 ± 100 kHz
1.1 : 1 ± 200 kHz
1.08 : 1 ± 100 kHz for dual-frequency version
1.12 : 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 (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
10
7
3.87
5.88
40
2
0.99
-0.04
20
8
4.46
6.50
40
3
1.55
1.90
30
10
5.65
7.52
40
4
2.12
3.26
40
12
6.85
8.36
40
5
2.70
4.31
40
14
8.05
9.06
40
6
3.28
5.16
40
16
9.25
9.66
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 (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
133
593
168
749
309
1378
2
10
3.3
19
6.2
30
9.8
191
852
261
1164
552
2462
3
20
6.6
29
9.5
40
13.1
249
1111
354
1579
796
3550
4
30
9.8
39
12.8
50
16.4
307
1369
447
1994
1040
4638
5
40
13.1
49
16.1
60
19.7
365
1628
540
2408
1284
5727
6
50
16.4
59
19.4
70
23.0
423
1887
633
2833
1528
6815
7
60
19.7
69
22.6
80
26.2
482
2150
727
3242
1772
7903
8
70
23.0
73
23.9
90
29.5
534
2382
814
3630
1991
8880
10
90
29.5
93
30.5
110
36.1
650
2899
1000
4460
2479
11056
12
110
36.1
113
37.1
130
42.6
767
3421
1187
5294
2967
13233
14
130
42.6
133
43.6
150
49.2
888
3938
1373
6124
3455
15409
16
150
49.2
153
50.2
170
55.8
999
4456
1559
6953
3942
17581

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
148
660
267
1191
313
1396
4.3
0.4
7.1
0.7
8.1
0.8
2
288
1284
528
2355
616
2747
9.2
0.9
14.8
1.4
17.5
1.6
3
428
1909
788
3514
919
4099
14.0
1.3
22.3
2.1
26.4
2.5
4
569
2538
1048
4674
1223
5455
18.7
1.7
29.9
2.8
35.4
3.3
5
709
3162
1308
5834
1526
6806
23.5
2.2
37.4
3.5
44.3
4.1
6
849
3916
1568
6993
1829
8157
28.3
2.6
45.0
4.2
56.2
5.2
7
990
4415
1829
8157
2132
9509
33.0
3.1
52.5
4.9
62.2
5.8
8
1112
4960
2071
9237
2412
10758
37.1
3.4
59.4
5.5
70.2
6.5
10
1393
6213
2591
11556
3019
13465
46.6
4.3
74.5
6.9
88.1
8.2
12
1674
7466
3111
13875
3625
16168
56.1
5.2
89.6
8.3
106.0
9.8
14
1954
8715
3632
16199
4232
18875
65.7
6.1
104.7
9.7
123.9
11.5
16
2235
9968
4152
18518
4839
21582
75.2
7.0
119.8
11.1
141.7
13.2

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. 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: 02/26/2007
Webmaster: Al Friend
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