Posted in Army Security Agency, military history, NSA, Shortwave, SIGINT, Signal Corps

Hammarlund R-1511/GR Receiver

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Found this interesting receiver at the most recent Meriden, CT Hamfest last October, and since the price was right hauled it home with me.  Why did it catch my eye? For starters, the construction is a dead giveaway that it is a commercial/mil-spec receiver of 1960s or so vintage. Second, the radio had no identifying markings, and no apparent evidence at first glance of being debadged. That is sometimes an identifier of equipment that saw clandestine service in its past life. Third, there was some circuit modules marked as “video converter” which had piqued my curiosity. Finally, if I was a little more awake that morning, I might have recognized the front panel as that of some variant of the Hammarlund SP600 which did see extensive government service. Regardless, it was a mil-spec HF receiver, probably a Black Radio, the price was right, and it was something you normally don’t see at a local hamfest. Once I got home, a Google image search found identical units, and identified it as being an NSA-issue R-1511/GR. Further Google searching discovered that a fellow hobbyist had scanned and uploaded the manual.

From what I discovered online, the R-1511/GR was developed for the National Security Agency in 1968, and was based on the Hammarlund SP600. It saw service until at least the mid 1980s, and based on my research appeared to be part of the AN/GSR-4 Store and Forward Environmental Collection System. With this system, wideband RF spectrum was recorded to magnetic tape for later analysis. While this is an easy task these days for any hobbyist with a PC, free software, and an SDR such as the Lime or HackRF One, the NSA was doing this in the 1960s.

Like a lot of gear at hamfests these days, this receiver was from a silent key’s estate, and its specific history, and that of the silent key, is uncertain. He was possibly in the ASA, NAVSECGRU, or maybe even USAFSS as they would have been the service members familiar with this system.  Did this piece of gear listen to the Soviets, the Chinese, or someplace in Central or South America before retiring to civilian life in some former veteran’s ham shack? We’ll never know, but we can safely guess that it was interesting in a “behind the curtain” manner.

The frequency coverage of this radio goes up to the 6 Meter ham band (50-54 MHz.), and the SP600  is still a good performing receiver by today’s standards. This unit, when not being used for displays, is going to be parked on the center of the 6m beacon subband to monitor and record VHF propagation conditions.

Manual:
http://www.nj7p.org/Manuals/PDFs/Military/TEM-0541-01-0A%201-Jun-68%20NJ7P.pdf

Posted in military history, New York, Signal Corps

Military History Display – 2019 Veterans Chow Down – Mahopac, NY

Last Month, a few fellow historians and I from the American Veteran’s Historical Museum did a display for the Veterans’ Chow Down held by the  PFC Joseph P. Dwyer Vet 2 Vet Program of Putnam County.

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Fellow historian Joe S. with his display of uniforms, headgear, and ephemera from the Vietnam War to the present.

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Fellow historian Paul M.’s World War II home front and USO display.

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My display of Cold War era radio gear.

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AN/PRC-25

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AN/URC-92

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R-1511/GR

Posted in amateur radio, living history, military history, Shortwave

World War II Hallicrafters

One of the visitors to my display at last Memorial Day’s FDR event was a lady who was happy to see the Signal Corps. represented there. In conversation, she told me that her father had served in the Signal Corps with the Ghost Army during World War II. We chatted a bit, and she went to go see the rest of the event. This was a common occurrence that weekend, veterans and their families stopping by to thank us for honoring those who had served, and to share stories. You cannot have history, after all, without the story.

The next day, I left my display for a bit to go have lunch with Carol, and upon my return, one of my fellow historians told me a lady had stopped by looking for me. Shortly afterwards, my visitor from yesterday stopped by holding a ziplock bag of ephemera which belonged to her father from his time in the Signal Corps, and that she wished to donate to the museum. I thanked her, and took down her information so she could be properly credited when it appears in a future display.

Upon examination, the bag held some 1950s Signal Corps documents telling me her father served past the war, two pieces of insignia, and two pictures dated 1941 on the back. One was a picture of the squad room our soldier was billeted on, and the other was a radio he owned while there. Intrigued, I set out to identify what model it was.

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As a ham radio operator with some boatanchor experience, I recognized the radio as a Hallicrafters. Hallicrafters was one of the first boatanchors I was exposed to, courtesy of a 1983 or 1984 article in CQ Magazine featuring Chuck Dachis, who is the hobby’s expert on them.

The date on the back of the picture was 1941, so I knew the radio was made before then. Consulting the pictures and dates in Radios By Hallicrafters, identification was narrowed down to either an SX-24 Skyrider Defiant or SX-25 Super Defiant. Both radios are very similar in appearance, but the most notable difference to me is that the earlier SX-24 has control settings sikscreened directly on the case for the two controls directly below and to the right of the frequency display, whereas the newer SX-25 only has a single line at 12:00 with the settings on the knobs themselves. Examination of the above picture shows the latter, which makes this unit an SX-25.

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I don’t know if the SX-25 was actually used in military service. The next model Hallicrafters made, the SX-28, did see use as the AN/FRR-2.  Available online documentation does not show any indication it was, and I’m guessing that the SX-25 in the picture was the soldier’s personal radio.

In 1941, just before our entry into World War II, the SX-25 was Hallicrafters’ newest model.  When war was declared, the US Army pressed into service all sorts of radio gear, so maybe a few SX-25s did make it into inventory.  Either way, this soldier thought enough of the SX-25 to buy one once he was at his duty station, or bring it from home. If anyone reading this has documentation or other evidence showing that the SX-25 was used as an issue radio, please send me an email.

Just recently, I was at a local Old-School Army/Navy store in Newington, CT called Military Specialties. I was introduced to them by a friend in the early 1990s after having moved to Connecticut for my first electronics job after having come off active duty.  On the shelf in the back among the other collectibles was a very clean looking Hallicrafters SX-25, among a few other vintage shortwave receivers.  Inquiring about it, I learned that Bill, one of the owners, was a shortwave aficionado, and that we both served in the same National Guard unit, albeit 40 years apart.  I bought the SX-25, but there are still some other clean-looking vintage shortwave receivers there for anyone looking.  They’ll probably need a little servicing and aligning, but afterwards they’d be a nice addition to someone’s radio collection.

NEAR-Fest and the Nutmeg Hamfest are this weekend. I’m thinking both would be a good venue to look for the PM-23 speaker that’s in the picture with the radio.