On Wed, Feb 15, 2017 at 11:29 PM, Tony Duell <ard.p850ug1 at gmail.com> wrote:
I think at one time radio amateurs (at least over
here) had to use 5 bit
ITA2
machines for RTTY.
Same here.
It may even be to this day that RTTY implies that,
and
that ASCII is classed as 'data'.
The FCC order authorizing Amateur Radio use of ASCII went into effect in
March of 1980, but at the moment I can't track down a copy of the actual
order. The current FCC regs (?97.309) are more recent, and lump RTTY and
"data emission" together, allowing ITA2, AMTOR, or ASCII, or, with
additional limitations, "an unspecified digital code". I suppose I could
use EBCDIC, FIELDATA, or the IBM Stretch character code, as long as I
didn't use it for the purpose of obscuring the meaning of the
communications, or to communicate with a station in a country with which
the US doesn't have an agreement allowing those codes to be used.
But the 5 level machines that were used over
here tend to be Creeds (Creed 7s, 75s and 444s
mostly).
I'm told that Teletype models 15, 19, and 28 were very common here. I've
mostly seen models 15 and 28. I've only once seen a mdoel 32 (ITA2
five-level version of model 33).
I've seen some Kleinschmidt teleprinters, but I've never seen a Creed.