[GreenKeys] Survey

[Bob Camp]

Hi

Each character has both start and stop. In normal code the stop bit is  
stretched a bit. It's perfectly possible to start up in the "middle"  
of a character. This can happen if you get a bit of interference in  
the middle of a line of print. When you start up like that, depending  
on the characters in the line, you may stay out of sync of a while.  
Any "high" followed by a "low" will count as a start / stop  
combination. That's true weather you have a mechanical gizmo watching  
the bits, or a computer.

The LTRS is all "high" for the data. It's a start bit followed by one  
enormous stop bit. If you are running along copying junk, it will get  
you back running right. In rare occurrences it will take two of them.

Bob


On Nov 3, 2007, at 9:03 PM, Ralph Mowery wrote:

>
> ----- Original Message ----- From: "Bob Camp" <ham at cq.nu>
> To: "Ralph Mowery" <rmowery28146 at earthlink.net>
> Cc: "Greenkeys List" <greenkeys at mailman.qth.net>
> Sent: Saturday, November 03, 2007 6:50 PM
> Subject: Re: [GreenKeys] Survey
>
>
>> Hi
>>
>> The "double LTRS" thing assumes that at some point in the previous   
>> line you got garbage and are now printing junk. The LTRS character   
>> will get you back "in sync" quickly. Doing it before the CR/LF  
>> makes  sure you get the CR/LF. Of course it may not give you enough  
>> time for  the CR on a Creed machine ....
>>
>> Bob
>>
>
> Bob how does the LTRS get you back "in sync" ?  Each character has a  
> stop bit at the end of it and each new character has a start bit.
>
> When sending at machine speed and with some demodulators with  
> Automatic threshhold correction it may help to send nonprinting  
> characters between the printing characters.  That is if you use a  
> computer to send with (maybe some fancy tape system) and type at  
> less than the machine speed, it may help with the demodulation.
>
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