[GreenKeys] M28 features for RTTY operation today?

[Russ Miller]

Nick,

I did a quick check with MMTTY - which is one of the most popular freeware
applications for sending and receiving RTTY using a computer.

MMTTY send CR LF when the "enter" key is pressed.

Hope that this helps!  See you on-the-air  73

Russ WA3FRP


On Sat, Feb 23, 2019 at 4:51 PM Ralph Irish <w8roi at wowway.com> wrote:

> *What a lot of 'Irv's enemies' didn't know was that after a few paper run
> outs, Irv came up*
> *with a stunt box fix that would not allow multiple LFs to take place
> unless some number of*
> *printing characters had been sent.  So, some clown would sit there and
> type endless LFs,*
> *laughing all the time, not knowing that in most cases, Irv was sitting on
> his end, laughing*
>
> *even harder as the machine cycled and only one or two line feeds were
> accomplished.*
>
>
> *-   -   -   -*
>
>
> *Not certain of the timeframe, but sometime later, Irv got to borrow some
> kind of 'mini-computer'*
>
> *(Data General comes to mind) and wrote routines to circumvent any such
> nonsense.  All data *
>
> *from the TU had to pass through the 'Mini'  thence to the Model 28's
> Selector Magnet Driver. *
>
>
> *He even wrote routines to make his 'output' have  7.5, 8, 9 and 10 unit
> code, with all of the excess*
>
> *being put into the STOP pulse.  This made for some most interesting
> 'sounding' mechanical action*
>
> *from the Teletype, whether it was a Model 28 or 15, etc.  Throughput was
> still very close to what*
>
> *it would have been with 7.41 or whatever.   I'm certain that the
> mathematicians among G/K can*
>
> *do some number crunching and convert to OPM and come up with some exact
> number of WPM.*
>
>
> *Irv was a nice guy, and he was misunderstood by many.  I was not 'one of
> his biggest fans', but*
>
> *you have to put credit where it belongs.  Without his efforts, those 100
> and some Model 28s would*
>
> *have been sold by Pacific Bell (or whomever) and never seen by any hams.
> You might say that he*
>
> *was 'ego driven' as are many creative people.  His original Mainline TT/L
> from the early-mid 60s*
>
> *was almost a 'giant step' past the W2JAV units very commonly used by
> many, back in the 50s*
> *through the early 60s.  Petersen's 1967 'revamp' called the TT/L-2 TU was
> almost as large a 'giant*
>
> *step' past the original TT/L, and that device won over many hams as far
> as striving for near perfect*
>
> *copy under varying band conditions.  There were PC Boards made for most
> of the circuitry, and*
>
> *other PC boards for specific sets of bandpass filters and Mark/Space
> channel filters.  A fellow in*
>
> *Texas whose name/nickname was "Curly" made some of these boards, and sold
> them for little*
>
> *profit.  He provided manufacturer's part numbers for tube sockets and
> terminal strips and other*
>
> *items for those who wanted a great looking and performing TU.  *
>
>
> *Over time, Petersen, with help from some Detroit area 'locals' came up
> with part value mods for*
>
> *the TT/L-2 and those who took the time to make the changes found the
> 'error rates' dropping a*
>
> *bit.*
>
> *At that time, Truman Boerkel, K8JUG (later K9JUG), worked for a "parts
> house" in the Chicago *
> *area and put together kits of parts for those who wished to have a
> finished unit work as Petersen*
>
> *wanted it to work.   I suspect that there are still many of those 'kit
> sourced' TT/L-2 units working*
>
> *quite well, if they were not allowed to 'sit idle' for decades.  (Nothing
> lasts forever!!)*
>
>
> *Petersen specified some special switches for the unit, and using another
> could have caused some*
> *'mode-switching glitches' and less than ideal print.  Truman made sure
> that the 'house' had the*
> *correct spec-ed switches for these kits.  (Not talking about rotary
> switches, but two and three*
>
> *position toggle switches.)  *
>
>
> *I have very find memories of those days.  I was fortunate to find a TT/L
> built with all 'point-to-*
>
> *point' wiring, on a 3" x 17" x 15" chassis, good 19" rack mount front
> panel and decent labeling*
>
> *on the panel.  It served me for years.  I had it on the summer "East
> Coast Autostart" channel,*
>
> *3637.5 KHz.  My receiver was a TMC with crystal positions with 'hz-shift'
> of the crystal circuit*
>
> *for near exact freq setting.  It also had a crystal socket for the BFO,
> for even better 'on the *
>
> *cycle' setting of the audio coming out of the receiver to the TU.  My 80M
> inverted "VEE" was*
>
> *about 30 feet at the feedpoint and I had favorably located trees for the
> ends.  One of the best*
>
> *time of my 'ham radio life' was that time period.  I built (and still
> have) a simple small chassis*
> *crystal oscillator circuit with a piston trimmer that I plugged into my
> Heath DX-35 transmitter's*
> *crystal socket.  By 'zeroing' stations on the air who were known for
> their precision, I stayed on*
>
> *freq, and had only one person ever question my signal frequency.  (We
> were both off a little bit!)*
>
>
> *Those were the days!!*
>
>
> *73,*
>
>
> *Ralph - W8ROI*
>
>
> *-   -   -   -*
>
>
> *Irv Hoff:             K8DKC,  Ann Arbor, MI   later W6FFC in California;
>   Military pilot, later airline pilot*
>
> *Keith Petersen: W8SDZ, Ohio, later Michigan resident.  Lived elsewhere at
> the time of his passing.*
>
> *                            Broadcast Engineer in Toledo, Detroit, and
> other employment situations including*
>
> *                            Chief Engineer of some TV stations in the
> south.  (Forgot details.)*
>
> ------------------------------
> *From: *"Russ Miller" <wa3frp at gmail.com>
> *To: *"Jim Haynes" <jhhaynes at earthlink.net>
> *Cc: *"Greenkeys" <greenkeys at mailman.qth.net>, "Nick England" <
> navy.radio at gmail.com>
> *Sent: *Saturday, February 23, 2019 2:59:36 PM
> *Subject: *Re: [GreenKeys] M28 features for RTTY operation today?
>
>
>    1. Non-Overline for the Teletype Model 28
>
>
>
> On a normal Teletype machine, when someone hits CR, the carriage will
> automatically come back but will not turn up a new line.  This is a nice
> feature for RTTY Art but a real problem if you are trying to copy a weak
> signal and you are already receiving partially garbled text.
>
>
>
> Fortunately, the Model 28 machines can be easily converted to avoid
> overlining. This change requires no new parts and can easily converted back
> to factory stock in a few minutes.
>
>
>
> Here are the steps to make the change:
>
>
>
>    1. Remove the roll of paper
>       2. With the motor running, look at the top of the stunt box.
>       3. Hit the CR key and some slot will show activity.  This should be
>       slot 5, counting from right to left as you stand in front of the machine.
>       4. Hit the LF key and two slots should show activity.  These should
>       be slots 38 and 40, counting from right to left as you stand in front of
>       the machine.
>       5. Leave slot 40 alone.
>       6. Remove the LP and take out the stunt box (after disabling all
>       power).
>       7. Swap the universal code bars in slots 5 and 38 and reassemble
>       the machine.
>
>
>
> Now, when the CR key is pressed, nothing happens.  When the LF key is
> pressed, both CR and LF occur at the same time.
>
>
>
> You will still have to hit the CR key when you are transmitting.  The CR
> character still needs to be sent to the distant machine.  It may seem
> awkward to type the CR key and have nothing happen. But, the simplicity of
> this change, the fact that no additional parts are needed and that it works
> so well are huge benefits.
>
>
>
> I hope that this helps!
>
>
> Russ WA3FRP
>
> On Sat, Feb 23, 2019 at 12:36 PM Jim Haynes <jhhaynes at earthlink.net>
> wrote:
>
>> I've forgotten the details, but one of the changes was because some
>> of Irv's enemies were starting up his machine on autostart and sending
>> continuous LFs to run all the paper out on to the floor.  Auto-CR-LF is
>> obviously good for radio because if you miss a CR or a LF you lose a
>> line of print.  And if you get a CR without a LF you lose a line of
>> print.  (Altho there were some TTY pictures where being able to overstrike
>> was essential)
>>
>> If people using computer-emulated TTY are failing to send proper end of
>> line characters then you aren't required to be able to receive from them.
>>
>> An electronic regenerative repeater is always good with a mechanical
>> Teletype because of the problem of false starts and missing stops that
>> result in several errored characters.
>>
>>         ---
>>
>>         "Ya can argue all ya wanna, but it's dif'rent than it was."
>>         "No it ain't! No it ain't!  But ya gotta know the territory."
>>                 Meredith Willson, The Music Man
>>
>>
>>
>
>
>
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