[RTTY] 300 baud RTTY

[Robert Chudek - K0RC]

Hello Mike,

Yes, you are correct that EXTFSK is hard coded to 45.45 baud. It would 
be great if that restriction could be removed but it doesn't appear that 
will happen.

No, the 110 baud and above test I did was not using EXTFSK. I had two 
computer systems 'tied together' and I was using the AFSK mode of the 
MMTTY software. It 'appeared' that the receive decoder in MMTTY was 
limited to 110 baud or lower. When feeding a higher rate to the receive 
decoder, the software spit garbage across the screen, like when you 
mismatch 45 & 75 baud RX & TX baud rates.

The MMTTY software is excellent, especially when you realize it was 
created 10+ years ago! The design criteria probably fell into the realm 
of "Nobody will ever need more than 640-Mb of memory" situation. :-) 
Right long with those huge 1-Gb disk drives I was installing in file 
servers. Now-a-days you can carry 32-Gb of storage (flash drive) on your 
key chain in your pocket!

73 de Bob - KØRC in MN

------------------------------------------------------------------------

On 6/6/2011 1:20 PM, Michael Haack wrote:
>    Not sure if you are having this same problem, but....I found the
> problem I was having in an old post.
>
> I'm running MMTTY with EXTFSK, and while I could set the software to
> 75baud, It would decode, but not send.
>
> It appears in an old post that , When running MMTTY with EXTFSK, you are
> Software limited to 45.45 in EXTFSK.
> Not sure if anyone ever found a work around.
>
> Back to the HAL cards I went.
> 73, Mike WB9B
>
>
>
>
>
> On 06/06/2011 12:26 PM, Robert Chudek - K0RC wrote:
>> You said: "...and could not print my own transmission properly on my
>> computer screen above 110 baud."
>>
>> Now that you mention this, I recall having the same problem with my
>> setup. But that was a few years ago when I tried this and I don't recall
>> the 'solution.' I am thinking (don't hold me to this) that there was a
>> limitation in MMTTY when going above that speed. It was not specifically
>> a problem with the computer itself.
>>
>> 73 de Bob - KØRC in MN
>>
>> ------------------------------------------------------------------------
>>
>> On 6/6/2011 10:13 AM, Ktfrog007 at aol.com wrote:
>>> Hi Bill,
>>>
>>> Well, I experimented with various settings (baud rates, marks and shifts)
>>> and could not print my own transmission properly on my computer screen
>>> above 110 baud, so I doubt I could copy anything intelligibly at 300 baud.  This
>>> is my computer limitation, I guess.  It can't keep up with  itself.  The
>>> rig was not transmitting.
>>>
>>> I suggest you find someone locally you can easily work with to run your
>>> tests.  I'm too far away and do not have enough power or a good  enough
>>> antenna system to make reliable skeds from sea to shining sea.
>>>
>>> Good luck and let me know how things go.
>>>
>>> 73,
>>> Kermit, AB1J
>>>
>>>
>>> In a message dated 6/6/2011 7:09:33 A.M. GMT Standard Time,
>>> dezrat1242 at yahoo.com writes:
>>>
>>> ORIGINAL  MESSAGE:
>>>
>>> On Sun, 5 Jun 2011 22:28:41 -0400 (EDT), Ktfrog007 at aol.com  wrote:
>>>
>>>> I'd like to try a  QSO with you, but doubt if I'd see  anything but
>>>> garbage.
>>> REPLY:
>>>
>>> What time and freq? I'm  retired so most any time at all is good, Can do all
>>> bands from 160 to 10  (except 60, where RTTY is illegal anyway).
>>>
>>> If we only hear garbage at  first, lets drop back to 45 baud and then try
>>> higher
>>> rates one at a time.  Ok? Everybody is welcome to join in.
>>>
>>> 73, Bill  W6WRT
>>> ______________________________________________