[WriteLog] MMTTY/2Tone (now Hardware generated FSK with microKEYER)

[Joe Subich, W4TV]

> The short answer is that you must go into the microHAM Router and
> check "Strict BPS" when you use Rttyrite's Hardware generated FSK.
> This may slow the data rate a bit, though Joe mentioned it was not
> as bad as he previously thought.

Ed is correct ...

When "C: Limiting Speed" is selected in MMTTY's "USB Port" dialog, MMTTY 
paces its FSK output - that is it sends one character to the
serial port every 165 ms.  This allows MMTTY to know what has been
sent (more importantly if there is still data to be sent) so it knows
when to drop PTT.  This is necessary because the system level drivers
for USB hardware have very large buffers that can not be disabled.
Software that does not use some form of pacing gets confused and either
sends too many diddles or drop PTT early (or both).

The equivalent to "limiting speed" in the Eltima VSPAX used in microHAM
Router is "strict BPS" which only sends a single character at a time to
Router.  Unfortunately, because the VSPAX is dealing with 8 bit data
instead of 5 bit (7.5 bit with start/stop bits) data, it calculates the
character rate at 176 (22 x 8) ms instead of 165 msec which results in
a slightly "slow" data (equivalent to 5N2 instead of 5N1.5).

When using "Hardware generated FSK" in WriteLog one must use "strict
BPS" in Router.  With MMTTY the alternative is to set no FSK port in
RTTYrite and configure MMTTY to generate the FSK.

Now that I have returned from my trip to Ohio for my mother's 90th
birthday, I will update the WriteLog examples for all of the microHAM
"Keyer" interfaces to document the new MMTTY interface and the option
of "Hardware generated FSK" with "Strict BPS" or MMTTY with "C:
Limiting Speed".  I had not expected a release while I was gone!

73,

    ... Joe, W4TV


On 4/1/2013 7:03 AM, Ed Muns wrote:
> This is similar to Jim N7US's experience he posted yesterday and its taken
> me this long to register what the issue might be.  I saw the same symptoms
> on a friend's system that used the original microKEYER, but the problem may
> be the same.
>
> The short answer is that you must go into the microHAM Router and check
> "Strict BPS" when you use Rttyrite's Hardware generated FSK.  This may slow
> the data rate a bit, though Joe mentioned it was not as bad as he previously
> thought.
>
> The long answer ...
>
> I forget why this isn't a problem with the MMTTY Plug-in.  Perhaps the
> Plug-in gets the COM port number from Rttyrite's Port menu but still uses
> MMTTY's FSK facility.  But, then I can't explain why this avoids the USB
> buffering problem in the Router that Strict BPS gets around. Perhaps some
> detail that differs between Rttyrite's hardware FSK and MMTTY's.  Joe will
> know.
>
> An alternative, if you use MMTTY as your main decoder/encoder, is to select
> "None" in the Rttyrite Port menu and use the MMTTY FSK feature, setting the
> COM port number on the TX tab of the MMTTY Options window.
>
> If using 2Tone for the main decoder, you must use Rttyrite's FSK facility
> since there is not true FSK capability.  If you use Hardware generated FSK,
> set "Strict BPS" in the Router.  If you use Software generated FSK, it only
> works with 45.45 Baud (60 wpm) RTTY.
>
> And, finally, there is the option of using 2Tone's "Pseudo FSK" mode but
> this requires a special hardware interface.  It is described in the 2Tone
> PDF:
>
> "TX FSK: The Pseudo FSK setting outputs a 5KHz tone on both left and right
> channels of the selected
> sound card. Tone is on for space and off for mark. A suitable detector
> circuit can be found at
> http://www.w1hkj.com/FldigiHelp-3.20/PseudoFSK.html but use 0.1uF in place
> of 0.5uF. The output
> connects to the FSK input of the rig. Search & Pounce: as the transmit
> frequency does not change
> with AFC, tune the rig so the small vertical AFC lines are co-incident with
> or very close to the long
> vertical lines. Not doing this will result in off frequency transmission."
>
> When Joe resurfaces, he may have further comment.  Let me know if this
> helps.
>
> Ed W0YK
>
> Gary AL9A wrote:
>> I seem to have hit a bit of a stumbling block...
>>
>> Downloaded WL V11.10G and installed the new update.  I
>> already had XMMT.ocx registered on my Vista machine because
>> of an earlier install of N1MM a couple of years ago. Cleared
>> out my RttyRite section in the ini file and then followed
>> Don's directions on his web page.  I can get both MMTTY and
>> 2Tone to run using the ocx option on the TU Type menu, but
>> there is something not right in both instances.  When sending
>> a macro the text appears to jump instantly onto the RttyRite
>> screen, but the transmission is a problem.  Either the TX
>> drops out right away after just a few characters are sent or
>> it sends a part of the string then hangs up for a couple of
>> seconds and sends more of the macro then hangs up again.
>> Sometimes it takes several seconds to TX to turn off despite
>> having %E at the end of the macro.  This happens with both
>> 2Tone and MMTTY under ocx control.  It sounds like those K3
>> ops who are using a CW paddle to key their RTTY transmissions.
>>
>> When I switch back to the MMTTY plug in choice in the TU Type
>> menu it transmits normally again.  The only thing I notice
>> that is different is that with the ocx option selected in the
>> Ports drop down list there are three FSK keying options.  The
>> last one in the list is checked - Hardware FSK.  I have the
>> microHAM Router software running and use the MK II for FSK.
>> Is there a setting somewhere I'm missing in RttyRite, MMTTY,
>> 2Tone or Router?  Not sure where to go or what to try next.
>
> _______________________________________________
> WriteLog mailing list
> WriteLog at contesting.com
> http://lists.contesting.com/mailman/listinfo/writelog
> WriteLog on the web:  http://www.writelog.com/
>