Thanks for the article! I had heard of "Twinplex", but never seen
a good description of it like was in this article.
I worked on the AN/FRA-86 (aka ASAV-133) DFSK demodulators that
must have been for Twinplex, but couldn't find any Twinplex
signals to copy, so never used them other than for normal FSK.
On Sat, Nov 8, 2025 at
5:42 PM Duncan Brown <[email protected]>
wrote:
Nick,
I've never seen the term "dot cycles per second" in
military TTY manuals before. In the introduction of TM
11-2241, it says that the CV-116 will operate at "speeds
as high as 100 dot cycles per second."
Your definition of "dot cycles" seems logical, but that
implies that the CV-116 could do 200 baud. In 1955, 75
baud equipment was just becoming available. I don't
think there was anything else faster. TM 11-2241 uses
the M15 (TG-7-B) as the example equipment.
Maybe the CV-116 really could do 200 baud, but the [LOW]
switch position was to optimize it for the present day
(1955) equipment speeds (45-75 baud). TM 11-2241, p 15,
para 20h of "Preliminary Starting Procedure", says to
"Set SPEED switch at the LOW position" without regard
to TTY equipment being used.
73,
Duncan
K2OEQ
On 11/8/2025 4:58 PM, Nick England via GreenKeys
wrote:
I am reading the CV-116 manual which
says select LOW for keying speeds up to 38 dot cycles
per second.
I *think* this is equivalent to 76 baud
because a “dot cycle” consists of a mark plus a space
element. Is this correct?
Note. The one thing AI apps are good at
is giving an answer that sounds good, whether actually
correct or not.