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220301986 and 1991 Perseus files

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  • MarkWA1ION
    Mar 1, 2014
    • 0 Attachment
      The following Perseus format files dubbed from videotape RF captures are now available:

      1 MAY 1986, 0759-0801 UTC, 410-2010 kHz (Craig Healy - metro-Providence, RI, USA)
      http://chowdanet.com/markc/rf/19860501_0759-0801z_410-2010.wav

      2 APR 1991, 0759-0801 UTC, 810-1610 kHz (Mark Connelly - metro-Boston, MA, USA)
      http://chowdanet.com/markc/rf/19910402_0759-0801z_810-1610.wav

      These were reduced to 2 minutes each from longer files by use of the Chuck Hutton 'WavChopper' program.

      Earlier information on the topic appears below.

      Mark Connelly, WA1ION
      South Yarmouth, MA, USA

      <<
      I am fascinated by the conversion of a broadband vhs tape recording to a 
      Perseus file.  Well done......

      So aligned freq for both, set PC date back, and played into perseus 
      aerial socket and press record?? Is that how it was done???

      And it worked????

      Any chance of posting a 5m or so toth Perseus file somewhere???

      For 1986 and 1991....??? Night time files would be of interest as well...

      Ken, Scotland
      >>

      <<
      I have converted the two best spectrum capture videotapes (1986, 1991) 
      to Perseus files and then dubbed off a few ID's with Total Recorder.  
      This is what I have so far:

      http://chowdanet.com/markc/dx_audio/id1_19860501_0500e.mp3

      ID's 5 a.m. EDT / 0900 UTC, 1 MAY 1986 from metro-Providence, RI (Craig 
      Healy VCR DX spectrum capture tape): WWKB-1520 NY, WTOP-1500 DC, 
      WPTR-1540 NY, WQXR-1560 NY, WCAU-1210 PA, WRCP-1290 RI, WHIM-1110 RI, 
      WHJJ-920 RI, WHN-1050 NY, WINS-1010 NY.

      ===

      http://chowdanet.com/markc/dx_audio/id1_19910402_0500e.mp3

      ID's 5 a.m. EST / 1000 UTC, 2 APR 1991 from Billerica, MA (Mark 
      Connelly VCR DX spectrum capture tape): WHDH-850 MA, WCAP-980 MA, 
      WBZ-1030 MA, WADN-1120 MA, WNEW-1130 NY, WMJX-1150 MA (ID for FM), 
      WKOX-1200 MA, WEZE-1260 MA, WJDA-1300 MA, WRCA-1330 MA, WFEA-1370 NH, 
      WLLH-1400 MA, WXKS-1430 MA, WTOP-1500 DC, WSSH-1510 MA, WQXR-1560 NY.

      ===

      Mark Connelly, WA1ION
      South Yarmouth, MA
      >>

      <<
      That's basically it Bill, though I think that 2 MHz would be about the 
      top of the baseband range.  Storing higher frequency blocks would 
      require a downconverter stage.  That, as far as I know, was the
      intelligence agencies' method employed at places like Menwith Hill (UK),
      Resolute Bay (Canada), Thule (Greenland), Incirlik (Turkey), the
      Aleutian Islands, and numerous other monitoring outposts in the '60s
      to snoop on the Russian bear (and probably the ChiCom's too).

      Regarding Craig's comment, I have identified that his recording starts 
      at 0859 UTC on 1 MAY 1986.  Lots of news about the Chernobyl nuclear 
      reactor accident a few days earlier.  Fun to hear 1560 WQXR doing 
      classical, as well as hearing contemporary hit music and oldies on 
      numerous other stations that are now boring talk ... aah the good old 
      days!  No TA's or Latin Americans, but what do you want with only about 
      40 dB of dynamic range?

      So, besides my 1991 stuff, now we have Perseus files from 1986!

      Mark Connelly, WA1ION
      South Yarmouth, MA

      -----Original Message-----
      From: Bill Nollman <billct97@...>
      To: CapeDX <CapeDX@yahoogroups.com>; badx <badx@yahoogroups.com>; am 
      <am@...>; irca <irca@...>
      Sent: Fri, Feb 21, 2014 8:32 pm
      Subject: RE: [CapeDX] Perseus captures from 1991

      OK, let me understand this… the idea was to take 0-150MHz add a 60Hz 
      sync signal to keep the VCR happy, store it to tape through the Video 
      IN jack then on output simply remove the 60Hz and you basically have 
      coming out what you put in? So simple its silly! I once used a Hi-Fi 
      VCR to capture 8 hours of FM DX audio. Hardly genius.
       
      From: CapeDX@yahoogroups.com [mailto:CapeDX@yahoogroups.com] On Behalf 
      Of Mark Connelly
      Sent: Friday, February 21, 2014 4:56 PM
      To: badx@yahoogroups.com; am@...; CapeDX@yahoogroups.com; 
      irca@...
      Subject: [CapeDX] Perseus captures from 1991

      I finally got around to going through a box of VHS videotapes from the 
      late '80s / early '90s spectrum capture experiments, as originally 
      developed by Craig Healy (NG1U), and mentioned in this article:

      http://chowdanet.com/markc/webpage/WA1ION/vcrdx.pdf

      There were about 6 tapes in the box.  Two of these, when played into a 
      receiver, had reasonable performance.

      One of these was the tape Craig had originally supplied me.  This was 
      made at his QTH near Providence, RI.  The whole AM band is captured.  
      Sensitivity on the lower half was quite low so it's primarily the local 
      stations such as 630, 790, and 920.  Some skip signals can be heard on 
      the upper half of the dial.  I still have to review the tape to 
      determine the exact date and times of recording.  Items on a news / 
      sports station, possibly with some Google follow-up, will nail down the 
      date.  At some point in the recording there should be a time check on 
      one station or another.  I looked into the lower shortwave spectrum but 
      noted little in the way of "real" (non-birdie) signals, so no CHU or 
      WWV assistance on the time.

      The second tape was one I made at Billerica, MA in April 1991 during 
      the "wee hours" of the morning: 0643-1043 UTC.  Because 50 kW WRKO on 
      680 is only 2.8 miles / 4.5 km from the receiving site, a notch filter 
      for 680 was inserted ahead of the VCR input.  Usable sensitivity for 
      the capture came in starting around 800 kHz and up.

      One thing that must be kept in mind is that this primitive version of 
      spectrum capture had a rather small dynamic range: only about 30 to 40 
      dB from a hashy noise floor up to the level of a strong local on the 
      verge of causing distortion and spurs.  The tapes, obviously, are not 
      going to produce much in the way of weaker signal DX.

      Before the tapes have a chance to deteriorate, I'm porting at least 
      some of the contents over to Perseus files.  This also gives a ready 
      method for sharing the experiment results with others.  I reset the 
      computer date/time so that the Perseus time-stamping is relatively 
      close to the occurrence of the original recordings.

      After I get all this stuff digitized, I'll go over it for any 
      interesting audio clips.

      Though the "VCR DX" method became known to the MW DX world about a 
      quarter century ago, it is widely believed that, as far back as the JFK 
      administration, "spook" agencies such as the NSA were able to store 
      substantial RF bandwidths for later review.  Broadcast studio grade 
      videotape, or something similar but custom-designed, was used.  
      Converters allowed any chunk of spectrum to be heterodyned to the 
      baseband range (0-3 MHz?) the tapes could accommodate.  The late Gordon 
      Nelson (WA1UXQ) seemed aware of it.  Maybe some tapes will show up at a 
      Fort Meade, MD fleamarket / yard sale so we can tune around and hear 
      stuff like Belize 834 and Bermuda 1235 once again, as well as 
      Murray-the-K on WINS proclaiming his status as the Fifth Beatle.

      Mark Connelly, WA1ION
      South Yarmouth, MA
      >>

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