[Milsurplus] Higgins PT Boat Whip Antenna?

[Laura and Jim]

The photos I've seen involve a round ceramic dome atop the cable trunk w/the whip coming out of it - no spring.

Photo shows "PT-557" on the conn(?), but I don't recall the source

There's a long shot of one here in the gallery, 4th row down:

http://www.usni.org/heritage/slideshows/leyte-gulf

I can send the close-up photo as needed.

73 DE JIM K6FWT