[GreenKeys] Model 15-A?

[Derek Cohn/WB0TUA]

Hi Bob,

Thank you very much for your good advice.  Let me first start by getting the 
equipment and inventorying what's there.  I'll follow up with photos, etc. 
and would love your continued assistance in getting this beast working 
again!

73,

Derek Cohn
Morse Telegraph Club - Alton Chapter
Office UD, Sine DJ
Amateur Radio Station - WB0TUA
1969 Brunswick M274A5 Mechanical Mule
----- Original Message ----- 
From: "Bob Camp" <ham at cq.nu>
To: "Derek Cohn/WB0TUA" <vibroplex at mindspring.com>; "Greenkeys ((E-mail))" 
<greenkeys at mailman.qth.net>
Sent: Thursday, February 10, 2005 5:07 PM
Subject: Re: [GreenKeys] Model 15-A?


> Hi
>
> I guess I'll jump in here and get a few of the basics covered. I'm going 
> to *assume* we are talking about a model 15 teletype and not something 
> else.
>
> A model 15 has been one of the staple items on the used Teletype market 
> since WW2. A fairly typical land line hookup would consist of a printer, a 
> keyboard, a local loop supply (say 125VDC at 60 ma) and a polar relay. The 
> polar relay would hook to the wire line and convert the polar "telegraph" 
> signals to the on/off pulses that the Teletype understands.
>
> Physically the 15 has three basic pieces. There's the printer / keyboard, 
> the table (usually metal) and the loop supply box. Whole thing is maybe 
> four feet tall by two feet by two feet. Black is a common color as is 
> green.
>
> Now for the fun part. The machines don't always run at the same speed. 
> They pretty much use the same code(s) but they run at different words per 
> minute. In order to get them to talk to each other you need both of them 
> to be running at the same speed. The second thing is that the RS-232 
> output of your 300 baud modem isn't quite up to driving a 125 volt / 60 ma 
> local loop. That part is easy to fix with a simple keyer board.
>
> What you are suggesting is fairly straightforward to do. The equipment is 
> available and hooking it up is not a "rocket science" sort of thing. If 
> you need more equipment the main issue is that it's big and heavy. Packing 
> it for shipment is a pain ....
>
> Take Care!
>
> Bob Camp
> KB8TQ
>
>
> On Feb 9, 2005, at 11:47 PM, Derek Cohn/WB0TUA wrote:
>
>> Dear Friends,
>>
>> I am a non-tty guy who is thinking about taking the plunge.  I was 
>> recently offered a teletype with a cryptic description "15-A".  Is that a 
>> standard Model 15 or possibly something else?  Apparently there are 
>> several items that come in the package (perhaps loop supply, terminal 
>> unit, etc.).
>>
>> Anyway, my primary interest is in landline Morse (railroad Morse) and I 
>> am active on the Morse Telegraph Club's dial-up telegraph circuit.  We 
>> use old 300 baud modems to FSK into a "hub" where up to 6 operators can 
>> telegraph.  We transmit a "mark" and "space" over the phone lines and a 
>> converter to generate a voltage to operate our telegraph instruments at 
>> each end.
>>
>> When I was discussing the teletype this evening on our virtual telegraph 
>> wire, I discovered that one of our group members, a retired AT&T 
>> technician, has a teletype that he would like to put on our telegraph 
>> wire if he can find another person who would be interested.  It stands to 
>> reason that we can subsitute the teletype for our hand keys or bugs and 
>> use the teletype to key our circuit.
>>
>> I'm curious if anyone has ever done something like this before.  Looking 
>> forward to hearing from you guys!  Also...is there anyone in the St. 
>> Louis, MO area who is familiar with mechanical teletypes that could serve 
>> as an Elmer as I try to get this project going?
>>
>> Thanks,
>>
>> Derek Cohn
>> Morse Telegraph Club - Alton Chapter
>> Office UD, Sine DJ
>> Amateur Radio Station - WB0TUA
>> 1969 Brunswick M274A5 Mechanical Mule
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>