Re: Gov't Wide Band Circuits/STU's
- --- In email@example.com, "OZOB99" <ozob99@...> wrote:
>Here are the pages I had saved on COMSEC; some may be familiar like Jerry Proc's site & NSA site.
> --- In firstname.lastname@example.org, David <wb8foz@> wrote:
> > On 7/8/11 9:59 PM, OZOB99 wrote:
> > > From what I've seen on related documents, the STU family ran 2400bps
> > > streams so most any 4 wire voice grade line would suffice; at 4800 "C"
> > > conditioning(envelope& amplitude delay equalization) might be needed.
> > > The older 50kb analog wideband was typically transported inter-city on a
> > > L multiplex group slot with LWM wideband modems and terminating in a
> > > KY-3 terminal at the customer's location.
> > I'm confused to some extent. I was sure most STII/KY71's used leased lines;
> > but I am equally sure they were also deployed overseas, so there must have
> > been some inverse mux scheme & voice-grade circuit, plural.
> There were Autosevocom lines overseas & Canada so ST2 could have used to some extent but I don't know the milage limit.Autosevocom lines had "C3 conditioning", which was supposed to allow several voice grade encryption schemes to work.The STU-3 was supposed to work on 2 wire dial up lines also, but I understand it was problematic.
> Most if not all the primary secure phone lines from the NMCC/ANMCC & other locations to unified & selected commands were 50kb analog wideband in the pre digital days, some up until the 1990's.
> Some of the JSCAN/COPAN (voice grade) circuits had C conditioning to allow secure voice, but I've heard from reliable sources it was rarely,if ever used on these networks;but they paid the bill(big$) well into the 1980's.
Searching on KY-3 & KY-9 within these pages will yield history,details & photo's:
This page has many recollections of the gear by users/techs: