[time-nuts] More pictures of the mystery Collins Ru

[David I. Emery]

On Sun, Jul 28, 2013 at 07:54:47PM -0400, Bob Camp wrote:
> Hi
> 
> ….
> 
> There was a suitcase Rb that was used to sync up Have Quick's on the ground. It was a Magnavox product rather than Collins. The idea was to get the radios netted up without *anything* going over the air. Since the radios used TCXO's, sync was fairly loose. I suspect that tightened up as they went through the various versions ...
> 
> Bob
> 
> On Jul 28, 2013, at 6:58 PM, Brooke Clarke <brooke at pacific.net> wrote:
> 
> > Hi:
> > 
> > The military UHF voice radio scrambling depends on accurate time, hence the Have Quick (and follow on programs) time transfer standard.
> > Rb standards were used to maintain that time in the early days.

	A minor quibble - HAVE QUICK is really not meant as a voice
"scrambling system" but an anti-jam ECCM technology.   If you hop around
every so often to a frequency that is unpredicatable (chosen by a
cryptographic random sequence) your opponent has to find and follow you
to jam you and do this fast enough to actually cause you problems.
Otherwise he is stuck with barrage jamming the entire band.

	Hopping like this does require synchronized clocks... thus
the Rb... in order to hop at the right time to the right place.

	There are several current and historic voice encryption systems
that provide strong voice security without hopping - lots of crypto
technology for that. But HAVE QUICK is often used with plain ole in the
clear AM voice and that voice can be reconstructed by having receivers
for each of the hop frequencies that vote on the strongest signal (or
some virtual equivalent of all of this done with FFTs and the like).

	 Most cryptosystems do not depend on precise time of day,
though some antique ones did... 

-- 
  Dave Emery N1PRE/AE, die at dieconsulting.com  DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."