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Re: [coldwarcomms] Re: VHF COTS DES radios, manuals , was: Cold War HF comms in the news

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  • David Lesher
    ... I ll ask my friend again. But this was how I recalled his telling me it. ... Sorry; I was unclear. It s the GE encryption that he s seeking the fine
    Message 1 of 21 , Nov 24, 2002
      Unnamed Administration sources reported that etaoin_shrdlu_00 said:
      >
      > --- In coldwarcomms@y..., David Lesher <wb8foz@n...> wrote:
      >
      > > But at some point, they had DVP and GE had nothing (yet). So
      > > the Feebes bought in. It used non-standard deviation, and this
      > > decimated the range.
      >
      > Deviation of DVP and DES is standard so it fits in a normal
      > channel allocation. The radios are still type-accepted and can be
      > used legally if you specify 20K0F1E as an additional modulation
      > type on your public safety or industrial/business license. I think
      > that the reduction in range was just due to needing a higher than
      > normal signal to noise ratio for the data recovery circuit to work.

      I'll ask my friend again. But this was how I recalled his telling
      me it.

      > > A friend has several DES's radios and keyloader; he'd love to
      > > find The Fine Manuals for same but they were limited circulation
      > > and are now obsolete.
      >
      > Not quite. Many of them are still available from Motorola,

      Sorry; I was unclear. It's the GE encryption that he's seeking the
      fine manuals for. He won't touch Galvin hardware. And GE-Lynchburg
      is no longer GE, it's someone overseas...

      Another story of his; he bought a GE handheld from a local area
      police auction. Got a bill of sale etc. Wrote for Fine Manuals.
      Turned out to be on NIS (Naval Intel Service) freq.

      NIS tried to hassle him into giving it back to them as it was
      ""stolen"" property. Trouble was, the loser [literal] had never
      reported it gone (hence the police got no traceback..) and was
      in fact still showing it on inventory; trying to cover up the
      loss. (Seems 'loser' left it somewhere...)

      Then they figured out my friend was a USG employee and tried
      to make trouble with his Procedural Security folks/re: his
      TS clearance. He responded to the Inspector General of the Navy,
      his Congresscritter, and his folks. Excrement everywhere.

      He offered to sell it back for what he'd paid, provided he got a
      USG check/receipt. ("How can I be sure I am actually returning
      it to the Navy if someone wants to give me $25 in cash?" he
      asked.) The file kept getting thicker.

      ISTM they finally paid him with a money order but had to sign
      a bill of sale he wrote, and he photographed them doing so.



      --
      A host is a host from coast to coast.................wb8foz@...
      & no one will talk to a host that's close........[v].(301) 56-LINUX
      Unless the host (that isn't close).........................pob 1433
      is busy, hung or dead....................................20915-1433
    • David Lesher
      ... Obviously, he could be wrong; his forte was always Generous Electric. -- A host is a host from coast to coast.................wb8foz@nrk.com & no one will
      Message 2 of 21 , Nov 24, 2002
        Unnamed Administration sources reported that etaoin_shrdlu_00 said:
        >
        >
        > Deviation of DVP and DES is standard so it fits in a normal
        > channel allocation. The radios are still type-accepted and can be
        > used legally if you specify 20K0F1E as an additional modulation
        > type on your public safety or industrial/business license. I think
        > that the reduction in range was just due to needing a higher than
        > normal signal to noise ratio for the data recovery circuit to work.


        I asked him &:

        |As I recall, they used the first generation (the only one available then)
        |of Motorola DVP (digital voice privacy) in the DES version (as opposed to
        |the Motorola proprietary version). The problem was that to get reasonable
        |speaker recognition, the digital data stream was sent at 13 kb/s, which, in
        |a radio system designed with a maximum deviation of 5 kHz., caused
        |problems. The result was that in order to make the DVP work, the deviation
        |was increased to about 8 kHz. and they had to increase the receiver IF
        |bandwith to accomodate the wider modulation envelope. Since FM transmitter
        |power output is constant, a wider bandwith is less energy per hz. (and a
        |wider receiver at the other end is more noise thorugh wider filters) the
        |overall result is a loss of about 50 % in range compared to normal FM voice
        |at 5 kHz. deviation.


        Obviously, he could be wrong; his forte was always Generous Electric.



        --
        A host is a host from coast to coast.................wb8foz@...
        & no one will talk to a host that's close........[v].(301) 56-LINUX
        Unless the host (that isn't close).........................pob 1433
        is busy, hung or dead....................................20915-1433
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