[R-1051] R-1051 Speakers

[paul swed]

David a great write up and it follows my experience with the services..
I decoded AP and UPI on HF then C band satellites. But as they went digital
I essentially had no way or any details to homebrew a solution. That was
the end of that.
I really enjoyed the raw barely edited news feeds straight from the field.
Use 2 X model 28 teletypes and lots of paper. Though not every day that
would have been quite expensive even back then.
The demods I would swear were 85 Hz but maybe they were 120. Its been a
long time ago.
I recall going to a UPI place in CT. and a fellow actually gave me several
narrow band demods.
They were a square box about 4 X 4 by 6 deep. Easily sat under a desk and
had the current loop supply and all. The filter slipped in and out so you
could use other channels.
Longgggg time ago but certainly enjoyed the pre-internet news.
Interestingly at that time there were no pop out adds in those feeds! It
was just raw well written news.

Regards
Paul

On Thu, Dec 12, 2019 at 2:13 AM David I. Emery <die at dieconsulting.com>
wrote:

> On Thu, Nov 21, 2019 at 10:17:52AM -0500, paul swed wrote:
> > UCC1 another memory from the past. I do have a operational ura17. That
> was
> > a cadillac when at home I used home brew demodulators as a young ham. The
> > UCC1 also taught me how to home brew narrow band demods for the AP and
> UPI
> > wire services in the early 80s through 1990. They were muxed at that
> time.
>
>         The 120 Hz spaced VFT mux FSK wire line signals used to
> distribute the low speed TTY AP and UPI wires directly to customers were
> put in service in the mid to later 60s FWIW... around 68 in upper NY
> state IIRC.   They replaced DC telegraph loops on copper pairs (with
> polar relays to key the magnets in the TTY machines) with a transistorized
> FSK demod and solid state loop keyer that sat on the table under the
> machine and was fed the VFT mux audio off a leased (and conditioned)
> telephone private line voice grade data circuit (also on a copper pair).
>
>         The channel (eg wire) that these demods tuned was typically set
> by plug in filters and discriminator modules.. though some later
> hardware used a superhetrodyne architecture and a PLL locked LO to allow
> channel changes with DIP switches.
>
>         FWIW it is also notable that - internally in telco plant -
> similar carrier telegraph circuits on voice grade channels were used as
> long ago as the 1930s though some of these were AM (OOK) rather than
> FSK.  And before that WU and other telegraph companies used various
> similar audio FDM multiplexing as well as the more common TDM on
> various telegraph lines.
>
>         There was an era when some of these wire service wireline VFT
> mux signals were uplinked as audio (itself muxed) on various satellites
> carrying  AP and UPI and other wire services ... these days there are
> actually still some AP text news streams on the AP TV MCPC carriers on
> various world wide C band birds, but of course as streams on a digital
> PID in an IP oriented format.
>
>         And in a few places there was some experimentation in the 70s
> with distribution of wire service VFT mux on FM SCA subcarriers...
> which died out as more folks got access through various satellite paths.
>
> --
>   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."
>
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