For more info see
NAVSHIPS 0967-177-3020, SHIPBOARD ANTENNA SYSTEMS
NAVSHIPS 900121(A) SHIPBOARD ANTENNA
DETAILS
Shipboard Antenna Details NAVSHIPS 900121(A)
Chapter 2 Installation Methods (change 1) - download
pdf
Chapter 3 Multicouplers - download
pdf
Chapter 6 Antenna Systems - download
pdf
Chapter 8 Installation Bibliography - download
pdf
Antenna Catalog Vol III, Ship Antennas (1960) - download 10 MB pdf
Technical Report - Nearfield Calculations for Shipboard Antennas
USS Canopus (AS-34) Antenna Plans
Need more info!! - Also see book "Shipboard Antennas" by Preston E. Law - link
- Range info
- Model building info
- Excellent magazine
article
Popular Mechanics April 1959
Antenna detail on CG-10 model
Antenna detail on CG-10 model
Typical Ship Antenna Arrangement
ANTENNA
& MULTICOUPLER
SYSTEM ON THE DL-2 (1952)
The multicoupling system to be installed on a new vessel, the Destroyer Leader DL-2 is shown in Figure 3- 30. The communications system on this ship uses a minimum number of antennas and is designed for maximum flexibility.
There are six antennas used with the multicoupling system: two 35 -foot whips and one wire antenna for receiving, and two 35-foot whips and one flat -top antenna for transmitting. The receiving antennas are located forward and the transmitting antennas are located aft so as to provide the best possible isolation between the two types. Provision is made to use any equipment with any of the antennas (except the flat-top) in the event of failure or damage to certain portions of the ship.
This ship uses three AN/SRA-9 receiving filter assemblies. Two located at the central Receiving Distribution Unit and one at the Auxiliary Distribution Unit.
Three transmitting filter assemblies are located at the Central Transmitting Distribution Unit. One of the filter assemblies, F-159/SRT has a crossover frequency of 375 kc with switching provisions for shifting the crossover frequency to 425 kc; another filter assembly, F-160/SRT has a crossover frequency of 1750 kc; the third filter assembly, F-161/SRT, has a crossover frequency of 3250 kc with provisions for shifting the crossover frequency to 3750 kc.
The three transmitting filter assemblies are stack-mounted. A four-pole, three-gang, Filter Selector Switch is mounted on the rear of the cabinets. The purpose of this switch is to allow both transmitters to be connected to any one of the three filter assemblies or to allow one of the transmitters to be connected directly to the antenna. This permits more versatile use of the transmitting equipments .
Discone-cage Antenna
(USS Wright CC-2)
Bow Discone-Cage Antenna
(USS Los Angeles CA-135)
- Article on discage design
- Good photo of Bow Discage on USS Canopus AS-34
- Discage & Whips aboard USS Hornet
The discone-cage antenna is actually two antennas combined into one structure, each antenna having a separate feedpoint. The highband antenna is of the discone type, utilizing an array of radial elements in a horizontal plane at the top of the cage as the disc and the upper section of the cage as the cone. The antenna is fed at the gap between the disc and the apex of the cone. The midband antenna consists of the entire cage section. The lower ends of the wires which form the cage are terminated on a collector ring which is insulated from the grounded supporting structure and used as the feedpoint. Feedpoint impedance-matching networks are required for both sections. A shorted coaxial stub is built into the upper section of the supporting mast for matching the upperband discone antennas to 50-ohm coax. It is occasionally necessary to add a series capacitor in the feedline, depending on antenna configuration details and the influence of antenna siting parameters. The matching network for the cage section is located in a deck-mounted enclosure at the feedpoint.
The discone-cage antenna must be located in a clear area. Adjacent structure will alter its radiation pattern characteristics and feedpoint impedances. One of the most successful locations has been on the bow of ships other than carriers. To avoid interference with anchor-handling requirements, the discage has been successfully installed on a bridge structure erected over the anchor machinery area. In other installations the antenna has been mounted on a pedestal, approximately 7 feet high, to reduce the electrical shock hazard to personnel.
Well, that discone has been deteriorating over the years, especially its foundation, that the USS Missouri Memorial Association is seriously considering removing it. That would leave KH6BB with only a couple verticals with which to make contacts. Considering how much better the discone works this would cause a serious decrease in the ability to contact KH6BB.
The members of KH6BB have made arrangements with the memorial association to try and raise funds to restore the discone antenna. The estimate for repairs is $45K along with our time and talent efforts. We are looking for any amounts large or small to keep our signal on the air. More details are available at http://www.ussmissouri.org/
Shipboard Sleeve Antennas
Another broadband antenna used extensively is the conical monopole shown in figure 3-36. Like the sleeve antenna, it is used both ashore and aboard ship. When operating at frequencies near the lower limit of the high-frequency band, the conical radiates in much the same manner as a regular vertical antenna (omnidirectional on the horizontal plane). At the higher frequencies the lower cone section radiates, and the effect of the top section is to push the signal out at a low angle. The low angle of radiation causes the skywave to return to the earth at great distances from the antenna. Hence, the conical monopole antenna is well suited for long distance communication in the high-frequency range.
Wire Antennas
See wire antenna hardware
Shipboard Wire Antennas
Blueprints of USS North Carolina BB-55 Wire Antennas
The twin-wire rope fan antenna is used to induce RF currents on a portion of the superstructure so that the superstructure in effect becomes part of the radiating system. Consequently, the configuration of the superstructure has direct impact on the performance of the twin-fan antenna. Shipboard experience and model measurements have served to identify certain relationships between topside configuration and the performance of fan antennas, but there are, as yet, no rigorous methodologies for designing fan antennas. The present twin-fan antenna has an open-wire feed system which is the most performance-sensitive portion of the installation.
Whip antennas
NT-66047 5 section, 35'
NT-66046 4 section, 28'
non-telescoping aluminum whip
more info
here
NT-66047 35' whips aboard USS Midway
Mounting insulator for NT-66047 is
NT-61335 or NT-61350
(IL-18/U or IL-19/U)
(NL222B31-203 or NL222B32-240)
Whip mount atop insulator
NT-66053 is a general purpose 25' non-telescoping whip antenna
weighing 30 lbs. It consists of three sections of stainless steel
tubing which screw together. In shipboard installations, the whip
mounts on Base Insulator NT-61428. In submarines Insulator Type
NT-61664B is used.
fiberglass 35 ft. whip antenna
NT-66047 was replaced by a 2-section 35' fiberglass whip AS-2537/SR
(see photos at right & below)
The AS-2537 is made in two fiber-glass sections bolted together with an integral mounting base of steel included in the lower section. The radiating portion of the antenna consists of six beryllium-copper strips laminated in fiber glass. In the AS-2537A, the two whip sections screw together and the insulator portion is also fiber glass.
USS Midway -
near whips NT-66047
far whips AS-2537/SR
(AS-2807 is the untrussed version)
This antenna consists of two AS-2537/SR whips mounted approximately 10 feet apart, tied together at or near their feedpoints, and fed with a single coaxial feedline. The impedance characteristics in a 50-ohm system are greatly improved over those of a single whip. A matching network is required when the antenna is used for transmitting but is optional for receiving. The twin-whip antenna is normally located on top of the pilot house, sometimes tilted 45 degrees towards the bow. The best location is on the centerline.
NAVSHIPS 91292
AN/SRA-17 LF/VLF antenna group
Components -
C-2536B/SRA-17 controller
TN-344A/SRA-17A tuner
or TN-418/SRA-17C tuner
AT-924B/SR antenna
or AS-2687/SRA-17D antenna
need more photos
manual NAVSHIPS 92299
C-2536B/SRA-17 controller
AT-924/SR Antenna is 129" long
TN-334 or TN-418 tuner
130.25" overall
AS-1857/SRA-43 Whip (5')
TN-438/SRA-43 Tuner
C-6828/SRA-43 Control
