Interesting HF Antennas aboard the USS Iowa Battleship

[Moleculo]

I took my Dad to tour the USS Iowa Battleship on Father's day, which is now permanently moored in San Pedro, California. Here are a few pics of some interesting HF antennas aboard the ship, as well as a good pic of the big 16 inch guns. Enjoy!

HF antenna at the bow:

HF antenna at the stern:

Vertical HF Antenna (there are several of these):

Plaque on the HF Vertical Antenna:

16 Inch guns looking aft from front deck:

16" gun projectile:

 

[Robb]

In Alameda CA (Alameda NAS; about ~45mi N of my QTH), they used to run a 2m repeater net from an aircraft carrier (USS Hornet) moored there. IIRC the repeater belonged to a chief from that ship in its heyday. The same group would also be allowed to conduct a tour through the ship. Don't know if they still run the net meeting there; will have to take a look.

EDIT:
http://www.qsl.net/nb6gc/


BTW - Howabout an analysis about the construction and principles of operations of those IA antennas?

 

[Beetle]

The first two are vertical monopole antennas, and probably for receiving only, since they are pretty easily accessible to anyone who might be strolling the deck. The theory is the same as a cage dipole: a fat antenna has greater bandwidth than just a little weenie wire.

Pictures 3 and 4 are different views of the same antenna. It's a receiving whip (you can tell by the blue base insulator; transmitting antennas of this type are virtually identical except they have red insulators).

Receiving antennas typically connect to the radio spaces directly, get routed through bandpass filters and end up at a patch panel where the radiomen (now 'Information Specialists', I believe) connect jumpers from antenna to receiver.

Transmitting antennas have couplers located very near the antenna itself, keeping the connection as short as possible. The couplers are adjusted by the output circuitry of the transmitter automatically. Transmitter functions are connected with the radio spaces by switch panels.

The Iowa class battleships were retired after Korea but reactivated for a time during Vietnam. The only one I've ever been aboard is the Missouri, which was a big tourist attraction here in Bremerton. Now she's at Pearl Harbor, and sitting at 000° relative, distance just a few hundred yards, is what's left of the Arizona.

 

[Moleculo]

The USS Iowa was active until the late '80's - it was retrofitted with Harpoon and Tomahawk cruise missiles and even a complete Phalanx "gatling gun" defense system.

An interesting thing about the vertical monopole antenna on the bow is that it is fed with two feed lines - one at the top for the upper HF spectrum and one at the bottom for the lower HF spectrum.

Beetle - thanks for the explanation on the RX HF antennas. I believe I counted at least four of those on board, there may have been more.

 

[KingCobra_CDX882]

Very Good Post.....Than
ks

 

[Klondike Mike]

Interesting plaque on the HF Vertical Antenna; Made in Canada.

Brought back some other memories for me; during the mid 90's I worked up and down the west coast teaching Microsoft computer courses. While in Microsoft land I visited Bremerton and the Missouri below. While teaching at the Alameda Coast guard island, I was able to get a private tour of the bridge on the second ship pictured. Wasn't paying any attention to the antenna's at the time.