Once you convert from Bell to English things make a bit more sense. One has to have a understanding of analog engineering terms but this oldie pretty much works the same as any Hayes etc modems.
The Modulator takes digital 1/0 levels and converts to one of two sine wave frequencies. The Limiter, Discriminator take from the sender the analog waveform (pretty much sine wave) and limits the amplitude and the discriminator decides if the frequency is a 1 or 0. The hybrid does impedance matching, echo cancellation etc. Many of the terminal block connections are for setting signal levels, later this was done with circuitry, but was too complex for doing in individual transistors, or at least in the space available. The Restrainer is filter looking for a particular frequency and when one comes down the line from the CO, it basically is a slow down signal. Timer - timing Send Break timer - think Signetics 555. I've not seen a clear breakdown of the relays AN (AK?) - Answer CON - Connected M - Momentarily hold OR - Originate vs Receive (controls the frequencies etc) S RU CY RB RS On Tue, May 9, 2017 at 9:06 AM, Chuck Guzis via cctalk < [email protected]> wrote: > Looking at this documents: > > http://www.samhallas.co.uk/repository/telegraph/data_set_101c.pdf > > I sill can't figure out what a lot of the stuff inside is for. > > --Chuck > > >
