[GreenKeys] Handset for teletype model 28

Thu Jun 4 01:07:25 EDT 2026

I trimmed this string – it was getting ‘verbose’…  ;}

I read the Wiki article – I don’t know what the actual frequencies of the TDD tones were – I’m hoping someone can supply that knowledge.
But, however, comma:  If the mark/space tones are 2150/2295, then you could find a standard telephone handset, wire into the earpiece, and try hooking that up to the output of the computer and inserting it in the coupler. Maybe an amplifier would be needed, dunno.

If all these “ifs” are satisfied, then you should be able to print ITTY on your acoustic coupler….

Cheerz
John

From: Gavin Wuchter <gavinwuchter at gmail.com>
Sent: Wednesday, June 3, 2026 9:58 PM
To: John Lawson <john at tubetestingpros.com>
Subject: Re: [GreenKeys] Handset for teletype model 28

After looking at some Wikipedia articles, I am holding out some hope for the coupler, since the article under history talks  about the 5 bit APCOM acoustic coupler which is who made the phonetype,  It was meant to be used by other TTY machines and language, so in theory in may work?

Here is the wiki:
https://en.wikipedia.org/wiki/Telecommunications_device_for_the_deaf<https://urldefense.proofpoint.com/v2/url?u=https-3A__en.wikipedia.org_wiki_Telecommunications-5Fdevice-5Ffor-5Fthe-5Fdeaf&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=MpuCMgbTcBz1ajjHC218bwC610gmsWSSxdIe-VtLTtarGOWwdFyT5MJoVryxRnUp&s=1rZyg94ni8TU2WdZJRn9ll2U9gi-ltl-Qj5KvMI7KlM&e=>

On Wed, Jun 3, 2026 at 11:48 PM Gavin Wuchter <gavinwuchter at gmail.com<mailto:gavinwuchter at gmail.com>> wrote:
Ah, well thank you for your help, what’s interesting is this machine was originally used by someone who was deaf back in the early 70s, and he paired the model 28 with the phonetype coupler to be able to “talk” to other people over the phone line, this model 28 was set up to be turned on when plugged in so the mod 28 would power on immediately when the handset is placed into the coupler because the mod 28 is powered through the coupler. So that is where the hope came from to be able to use it like it use to be used. I have watched curiousmarc in the past, it completely skipped my mind to think about him again. I will look into a TU, I know there are the chords that come out my mod 28 already, one is keyboard and one is magnet, that were at one time meant to plug into the coupler since it has those ports labeled on the back of it, so hopefully down the road that will make it easier, I do know that I was able to get the mod 28 to print some garbage through my system when the handset is in the coupler, but nothing of substance. Thank you for your help and I will look more into a TU.

If it is of interest I do have a scan of the manual-ish for the phonetype

-Gavin

On Wed, Jun 3, 2026 at 11:31 PM John Lawson <john at tubetestingpros.com<mailto:john at tubetestingpros.com>> wrote:
Greetings Gavin!
Thanks for jumping into the deep end of Teletypery!

Ultimately what you will want is a source of Baudot signals and a piece of equipment to decode the tones into pulses to operate the selctor magnets of your machine. You DO NOT WANT a coupler – what David was doing has to do with 70s personal computing – however he has got a Mod 14 and a Mod 15 working.  I alos will point you to ‘curiousmarc’ on YouTube. He has restored (back to nicer-than-factory) several TTY devices.

The source of the signals can come from any one of the several streaming services who convert text into “AFSK” (Audio Frequency Shift Keying” and stream it over the Net.  These are a set of two alternating pitches with the frequency of 2125 and 2295 htz. These alternate according to whether the bit making up a specific letter or character are ‘1s’ or ‘0s’ (called ‘mark’ and ‘space’ in the TTY world)

You will want some form of what is known as a “TU”, or Terminal Unit – basically a modem that takes the encoded audio and makes pulses out of it. These pulses are then used with a relay to make and break your “Local Loop Supply” which is connected to the Selector Magnets in your Machine.

When the Selector Magnets vibrate according to the pulses being decoded, it causes the machine to print whatever is being sent.

So you’ll want to scrounge up a suitable Terminal Unit. Since your Model 28 is currently typing according to it’s keyboard, you already have a Loop Supply. You will want to interpose a relay (mechanical or solid state) into the line that goes from the power supply, thru the keyboard, into the typing unit selector magnets and back (the “Local Loop”). Typing from the keyboard directly to the printer is called “Local Mode”.

Ask The Group if anyone has a spare TU of some kind that they would be willing to part with (I do not at this time…)

Then stream ITTY (or similar), apply the audio from your computer to the input of the TU, and use the TU’s “keying” output to drive your Mod 28.

It’s pretty easy – it will be difficult finding the right wire terminal to attach to, but plenty of Greenkeyers have Model 28s in daily use with ITTY, so tey will know exactly.

I have a Model 15 and I use a Dovetron TU from the late 70s.  But there are many many TUs extant.

And PS: I’m also a musician – keyboards – as a child I trained for the concert stage (I wanted very badly to be Van Cliburn) but I’m more of a composer – I don’t have “reproducer Genes” although I can get around fairly well on Things With Keys. [except damn accordions! “Use an Accordion, go to Prison!]

Cheers
John Lawson
KB6SCO
Carson City NV

From: greenkeys-bounces at mailman.qth.net<mailto:greenkeys-bounces at mailman.qth.net> <greenkeys-bounces at mailman.qth.net<mailto:greenkeys-bounces at mailman.qth.net>> On Behalf Of Gavin Wuchter via GreenKeys
Sent: Wednesday, June 3, 2026 8:56 PM
To: hwhall at aol.com<mailto:hwhall at aol.com> <hwhall at compuserve.com<mailto:hwhall at compuserve.com>>
Cc: greenkeys at mailman.qth.net<mailto:greenkeys at mailman.qth.net>
Subject: Re: [GreenKeys] Handset for teletype model 28

Ok, I will look into that as well, thank you!

On Wed, Jun 3, 2026 at 10:53 PM hwhall at aol.com<mailto:hwhall at aol.com> <hwhall at compuserve.com<mailto:hwhall at compuserve.com>> wrote:
Other than the tones, there's the sending speed that must match. You may want to verify the coupler's loop keying circuit is 100% okay, too.

Wayne

On Wednesday, June 3, 2026 at 09:48:42 PM MDT, Gavin Wuchter via GreenKeys <greenkeys at mailman.qth.net<mailto:greenkeys at mailman.qth.net>> wrote:

That was the goal, but I am new to this (I am a musician, this is the hobby to keep me sane) I did see a video by Usagi Electric that a coupler was used and the ITTY tones into a coupler to print on a model 15, unless I missed something which is totally possible,

Here is the video:
https://youtu.be/sSiVYgot9SI?si=igRFAfj7NvoKzAPB<https://urldefense.proofpoint.com/v2/url?u=https-3A__youtu.be_sSiVYgot9SI-3Fsi-3DigRFAfj7NvoKzAPB&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=_gD2tevewb25DQRWEsFwZPmHk6DV7FieR8zhKq3pyTI&e=>
Thank you!

On Wed, Jun 3, 2026 at 10:43 PM hwhall at aol.com<mailto:hwhall at aol.com> <hwhall at compuserve.com<mailto:hwhall at compuserve.com>> wrote:
> It's not clear to me... are you hoping to feed ITTY tones into the phone coupler & the coupler to drive the teletype? Are you sure ITTY is sending out tones that are compatible with the phone coupler? (I haven't used ITTY yet.) IIRC, the phone line teletype operations used different tones than are commonly used in on-the-air AFSK RTTY. There may be a tone mismatch that's causing the poor copy.
>
> Wayne
> WB4OGM
>
> On Wednesday, June 3, 2026 at 09:18:53 PM MDT, Gavin Wuchter via GreenKeys <greenkeys at mailman.qth.net<mailto:greenkeys at mailman.qth.net>> wrote:
>
> hello again!
>
> I am having some success with my teletype model 28 ASR, I got it power on and typing! Very exciting, now I would love to get it to print information, like the ITTY broadcast. I currently have a phonetype coupler with it that I put together with a cell to Jack since that is the only thing I have on hand at the moment, but it being a cheap Bluetooth converter the quality isn’t near enough for the teletype to decode. but the cell to Jack also doesn’t natively play audio through its speaker, but with what I was able to put through it my model 28 was only able to get a few characters at most. So I am trying to find a way to if possible play the audio through a handset to get it to print information.
>
> Here is one option I have seen:
> https://payphone.com/handset-with-3.5mm-trs-audio-jack-hs-trrs-1.html<https://urldefense.proofpoint.com/v2/url?u=https-3A__payphone.com_handset-2Dwith-2D3.5mm-2Dtrs-2Daudio-2Djack-2Dhs-2Dtrrs-2D1.html&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=_k5mkpNpbGUDWgmuzB9K0MLL7X65isBrfO8BLZ8cdHY&e=>
>
>
> I don’t know what other options are out there for me and this machine,
> I have owned other model 28s and also 15s and 33s. But this is the first time I am really trying to do something cool with a teletype.
>
> For the handset I listed above I would plan to plug it into a laptop to get the signal through it,
>
> But let me know what other people have tried and done before.
>
> Thank you all in advance!
>
> Sincerely,
> Gavin Wuchter
>
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys<https://urldefense.proofpoint.com/v2/url?u=http-3A__mailman.qth.net_mailman_listinfo_greenkeys&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=0_gCmC_-eJ0ySJhvhXCCdHIDiffHEcIz26KUqHN1zQA&e=>
> Help: http://mailman.qth.net/mmfaq.htm<https://urldefense.proofpoint.com/v2/url?u=http-3A__mailman.qth.net_mmfaq.htm&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=7j4c_cRusr1sr2PMvn1V6ZLoT2XgVAWcllDKVbSrEtE&e=>
> Post: mailto:GreenKeys at mailman.qth.net<mailto:GreenKeys at mailman.qth.net>
>
>>>> Jordan Spencer Cunningham's GreenKeys Search Tool: https://teletype.net/gksearch<https://urldefense.proofpoint.com/v2/url?u=https-3A__teletype.net_gksearch&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=YsfmnYwKSCwpS5ngoZlD8XtT_3k79OrhWQ17l0ZZIEs&e=>
>>>> 2002-to-present greenkeys archive: http://mailman.qth.net/pipermail/greenkeys/<https://urldefense.proofpoint.com/v2/url?u=http-3A__mailman.qth.net_pipermail_greenkeys_&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=MLg0xsQ5PDmpXi6BzWOl3dq3Q-LNtQupxVMGeIttT6g&e=>
>>>> 1998-to-2001 greenkeys archive: http://mailman.qth.net/archive/greenkeys/greenkeys.html<https://urldefense.proofpoint.com/v2/url?u=http-3A__mailman.qth.net_archive_greenkeys_greenkeys.html&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=KDBtFAT0QhJ0TGyNweclw2O1Bpf-Vl8-dO6Dj6iX01M&e=>
>>>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool: http://comcents.com/tty/greenkeyssearch.html<https://urldefense.proofpoint.com/v2/url?u=http-3A__comcents.com_tty_greenkeyssearch.html&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=CeoCChZrf2Bssw39Mfs-JduKw3L2snsYdDhXxua8WC4&e=>
>
> This list hosted by: http://www.qsl.net<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.qsl.net&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=mkpgwDNnvmP6efM17Fk3EAYLxnImB1WuiWYezzkNHFo&e=>
> Please help support this email list: http://www.qsl.net/donate.html<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.qsl.net_donate.html&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=Zd9cV330VbPvWA7GeDd8pUZRfaoV4nIrb2KGlP4oZ2k&e=>
> Message delivered to hwhall at compuserve.com<mailto:hwhall at compuserve.com>
>

______________________________________________________________
GreenKeys mailing list
Home: http://mailman.qth.net/mailman/listinfo/greenkeys<https://urldefense.proofpoint.com/v2/url?u=http-3A__mailman.qth.net_mailman_listinfo_greenkeys&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=0_gCmC_-eJ0ySJhvhXCCdHIDiffHEcIz26KUqHN1zQA&e=>
Help: http://mailman.qth.net/mmfaq.htm<https://urldefense.proofpoint.com/v2/url?u=http-3A__mailman.qth.net_mmfaq.htm&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=7j4c_cRusr1sr2PMvn1V6ZLoT2XgVAWcllDKVbSrEtE&e=>
Post: mailto:GreenKeys at mailman.qth.net<mailto:GreenKeys at mailman.qth.net>

>>> Jordan Spencer Cunningham's GreenKeys Search Tool: https://teletype.net/gksearch<https://urldefense.proofpoint.com/v2/url?u=https-3A__teletype.net_gksearch&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=YsfmnYwKSCwpS5ngoZlD8XtT_3k79OrhWQ17l0ZZIEs&e=>
>>> 2002-to-present greenkeys archive: http://mailman.qth.net/pipermail/greenkeys/<https://urldefense.proofpoint.com/v2/url?u=http-3A__mailman.qth.net_pipermail_greenkeys_&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=MLg0xsQ5PDmpXi6BzWOl3dq3Q-LNtQupxVMGeIttT6g&e=>
>>> 1998-to-2001 greenkeys archive: http://mailman.qth.net/archive/greenkeys/greenkeys.html<https://urldefense.proofpoint.com/v2/url?u=http-3A__mailman.qth.net_archive_greenkeys_greenkeys.html&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=KDBtFAT0QhJ0TGyNweclw2O1Bpf-Vl8-dO6Dj6iX01M&e=>
>>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool: http://comcents.com/tty/greenkeyssearch.html<https://urldefense.proofpoint.com/v2/url?u=http-3A__comcents.com_tty_greenkeyssearch.html&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=CeoCChZrf2Bssw39Mfs-JduKw3L2snsYdDhXxua8WC4&e=>

This list hosted by: http://www.qsl.net<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.qsl.net&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=mkpgwDNnvmP6efM17Fk3EAYLxnImB1WuiWYezzkNHFo&e=>
Please help support this email list: http://www.qsl.net/donate.html<https://urldefense.proofpoint.com/v2/url?u=http-3A__www.qsl.net_donate.html&d=DwMFaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=p4uj4qZVe0q2KIXBEwvZA3BicRkyIOf6Xcp1t9RPVQ0&m=wBfRjImlj-Il86nHPFQmze8hFNiKQZQg-ak-SioLzWJZiIwUgnELV_BHSZ6Dp-vL&s=Zd9cV330VbPvWA7GeDd8pUZRfaoV4nIrb2KGlP4oZ2k&e=>
Message delivered to hwhall at compuserve.com<mailto:hwhall at compuserve.com>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/greenkeys/attachments/20260604/9b7835b0/attachment.html>