[R-390] R-391/URR (MOD) - Direction Finder Set AN/FRA-44 --- Receiving Set AN/FLR-7
Clay Curtiss WA7KBR
[email protected]
Wed, 28 Jan 2004 23:13:43 -0800
Thanks! That would be great.
Clay
----- Original Message -----
From: "Ed Zeranski" <[email protected]>
To: "Clay Curtiss WA7KBR" <[email protected]>
Sent: Wednesday, January 28, 2004 4:20 PM
Subject: Re: [R-390] R-391/URR (MOD) - Direction Finder Set AN/FRA-44 ---
Receiving Set AN/FLR-7
> Will look, I can probably get it and by now it and it is probanly un
> classified.
>
> EdZ
> ----- Original Message -----
> From: "Clay Curtiss WA7KBR" <[email protected]>
> To: <[email protected]>
> Sent: Wednesday, January 28, 2004 3:05 PM
> Subject: Re: [R-390] R-391/URR (MOD) - Direction Finder Set AN/FRA-44 ---
> Receiving Set AN/FLR-7
>
>
> > Hi Bob,
> > I know very little of it's history. I acquired it from another ham
15-20
> > years ago. He was in the military and being transferred, so he didn't
> want
> > to haul it with him. I checked and his license is still current and
he's
> > living in my area again, so I might contact him and see what he
remembers,
> > if
> > anything, about the unit.
> >
> > I have discovered a little more about the receiver itself. It was part
of
> a
> > NRL project called Project Boresight. It received an NRL Innovation
Award
> > in 1998 (http://www.nrl.navy.mil/NewsRoom/images/75awards.pdf). Here's
> > part of the text:
> >
> > During the 1950s and 1960s, NRL demonstrated technology that
permitted
> > a radical improvement in the performance of high-frequency direction
> > finding (HFDF) networks and oversaw the deployment of this
technology
> > in Project Boresight and Project Bulls Eye.
> >
> > The first of three innovations that underlay this work was
> retrospective
> > direction finding. Previously, all stations in an HFDF network were
> > required to measure characteristics of the same signal while
> > transmission
> > was still occurring; after-the-fact easurements were needed.
> Previous
> > attempts at NRL1 and elsewhere were limited by storage bandwidth and
> > recorder instabilities. Recording significant fractions of the
HF
> > spectrum and using a digital method for overcoming recorder
> > instabilities
> > enabled retrospective DF. This was the basis of the 1960
> quick-reaction
> > Project Boresight that deployed the AN/FLR-7 and AN/FRA-44
> > worldwide.
> >
> > Project Boresight's crucial contribution to national defense was
> > recognized by the awarding of the Distinguished Civilian Service
> > Award to NRL's R.D. Misner and M.J. Sheets.
> >
> > A reference is also made to the following:
> >
> > Gleason, R.F. and Greene, R.M., "A Wide-Aperture HF
Direction-Finder,"
> > NRL Memorandum Report 746, October 1957.
> >
> > If anyone has a copy of this report, please let me know.
> >
> > Thanks,
> > Clay WA7KBR
> >
> >
> >
> > ----- Original Message -----
> > From: "robert J. wagner" <[email protected]>
> > To: "'Clay Curtiss WA7KBR'" <[email protected]>
> > Sent: Wednesday, January 28, 2004 9:06 AM
> > Subject: RE: [R-390] R-391/URR (MOD) - Direction Finder Set
AN/FRA-44 ---
> > Receiving Set AN/FLR-7
> >
> >
> > > Hi Clay - Sounds interesting - do you know any of the history
> > > of the radio (i.e. where did it come from, how did you acquire
> > > it etc). The FRA-44 dates to the early 60s and was unique to
> > > the Navy. BobW
> > >
> > > -----Original Message-----
> > > From: Clay Curtiss WA7KBR [SMTP:[email protected]]
> > > Sent: Wednesday, January 28, 2004 12:27 PM
> > > To: [email protected]
> > > Subject: [R-390] R-391/URR (MOD) - Direction Finder Set AN/FRA-44 ---
> > Receiving Set AN/FLR-7
> > >
> > > Hi,
> > > I'm new to the list and looking for some advice on an R-391 (S/N 145)
> that
> > I
> > > have. It was an original 1951 Collins unit (contract 14214-PH-51-93)
> and
> > > was modifed by RCA for the Navy and has an additional 3"x2"metal tag
on
> > the
> > > front panel below the function switch. It reads as follows:
> > >
> > > R-391/URR (MOD)
> > > RECEIVER, RADIO
> >
>
> -------------------------------------------------------------------------
> > > A UNIT OF DIRECTION FINDER SET AN/FRA-44 (XN-1)
> > > COUNTER MEASURES RECEIVING SET AN/FLR-7 (XN-1)
> >
>
> -------------------------------------------------------------------------
> > > MODIFIED FOR
> > > NAVY DEPARTMENT - BUREAU OF SHIPS
> > > BY CONTRACTOR
> > > RADIO CORPORATION OF AMERICA
> > > CAMDEN, NJ
> > > CONTRACT NObsr 81315
> > > US
> > >
> > > I've searched this list's archives, but find no mention of it. I
tried
> > > google and came up with a reference to Antenna AN/FLR-7 on
> www.r-390a.net
> > in
> > > the FAQ as follows:
> > >
> > > This Wullenweber antenna, also known as a Circularly Disposed Antenna
> > Array
> > > (CDAA), consisted of a large number of 200 foot towers arranged into a
> > ring
> > > more
> > > than 1300 feet in diameter. An inner ring of shorter towers competed
> the
> > > array.
> > > The antenna reportedly operated from VLF well into the VHF frequency
> > range.
> > > It
> > > provided direction finding accuracy to within two or three degrees,
> > > according to
> > > some reports.
> > >
> > > When I first got it, it worked but always had ringing in the audio. I
> > > suppose it could have been modified to have a very narrow IF bandpass.
> > >
> > > Does anyone have any info on how this R-391 was modified by RCA? I
> > suspect
> > > that there weren't very many of these made, and I don't know if it is
> rare
> > > enough or interesting enough for anyone to care about. Would it be
best
> > to
> > > leave a unit like this in it's current configuration, or to try to
> convert
> > > it back to a stock R-391 again?
> > >
> > >
> > > Thanks for any and all help.
> > >
> > > Clay
> > > WA7KBR
> > >
> > > _______________________________________________
> > > R-390 mailing list
> > > [email protected]
> > > http://mailman.qth.net/mailman/listinfo/r-390
> > >
> >
> > _______________________________________________
> > R-390 mailing list
> > [email protected]
> > http://mailman.qth.net/mailman/listinfo/r-390
> >
>