[Milsurplus] Mystery Antenna

[Doug Hensley]

Nick, I saw a similar structure when I did some training on the USS Enterprise, CVS-12, TDY from my tin-can.  On a hunch I forwarded the picture to George Fredericks, a retired Navy Radio Technician.  See below.  Harbor Control circuits as well as NAVCOMSTA's always maintained watches on HF even after going UHF.
Doug


Date: Tue, 27 Jan 2015 09:42:55 -0800
Subject: Re: Mystery Antenna
From: gefred08 at gmail.com
To: w5jv at hotmail.com

Yes, I am sure that is correct. The Navy needed a half dozen if not more HF whips on carriers. Due to flight ops and entering ports with low bridges they ended up defaulting to deck edge locations, at much better spacings, with a very simple counter balanced tilt over mechanism.  When tilted over they were 90 degrees from vertical, and still somewhat usable. And much-much easier to service when tilted towards the flight deck. Washing insulators became a breeze also.  This photo depicts an attempt to have your cake and eat it too design.  Objective was to never remove any of the whips from service especially off the coast of Vietnam, where flight ops reached rediculous levels by the late 60's. So they perched them all up on that post & platform arrangement. It did not work well in practice though. The view in the background is Victoria Peak and HK harbor BTW.  And the faint vertical lines under the platform have to be damage to the photo is my guess. Anyway, this must approach must have cost the radiomen & ET' s a lot of casualties. Transmitting out one antenna at high power could literally fry the adjacient transmitters' output circuits, let alone blow away any receivers in use (think transceivers like URC-32...).  Most importantly this cluster approach would be a tremendous generator of wideband EMI that had to drive both the radio and ECM folks nuts.  So, not a very good approach, even with brute force filter banks to cope, etc.  The shipboard Navy finally designed & successfully fielded a single broadbanded antenna & tuned filter technology that greatly improved the situation. And they usually placed it just behind the mack, which held the bridge etc.  But even with deck edge whips & broadbanded antennas, calming down HF receiver issues still rankled them until the SATCOM receiver hit the fleet. That UHF  receiver had up to 15 data channels, all 75 baud and directly usable on all ships with existing terminal gear, patching, crypto & tty in particular. I know because I was on the big team that made that happen fleetwide in less than five years. It was a blast to go all over and solve these problems, especially after living them literally 24/7 on USS CAMP for years on end....


On Jan 27, 2015 7:15 AM, "Doug Hensley" <w5jv at hotmail.com> wrote:



George,
Take a look at the attached picture.  Is that antenna structure to the left an HF array of whips or what do you think?
Doug