[WriteLog] Hardware Generated FSK

Joe Subich, W4TV lists at subich.com
Mon Apr 1 15:42:53 EDT 2013


On 4/1/2013 2:31 PM, Ed Muns wrote:
> Joe will have to address this.  The problem is between Rttyrite Hardware
> generated FSK and microHAM Router.  There is no speed issue with direct COM
> port FSK/PTT keying.

There is *no problem* between RTTYrite's Hardware Generated FSK and
microHAM Router if they are configured correctly.  I spent dozens of
hours checking all the permutations of Hardware Generated FSK, Software
generated FSK (TxD), and MMTTY Generated FSK during the beta process.
All versions work as expected - and display the expected limitations -
with Hardware Generated FSK creating 5N8 vs. 5N7.5 due to the 8 bit
calculation in the Eltima VSPAX.

I have measured the character rate for 5N7.5 (MMTTY) and 5N8 (Hardware
generated FSK with "Strict BPS") on long messages.  The difference is
less than 5% (1/16) as expected.  The difference is less that one would
find between 8N1 and 8N2 ASCII and has *no impact* on performance in an
asynchronous environment like RTTY.

Again, for those who are concerned by the long stop bit - allow MMTTY
(the OCX version) to generate FSK with the USB Port pacing enabled.
Check Port=NONE in RTTYrite (Hardware generated FSK will be checked but
grayed out) and select the FSK port in MMTTY (Options -> Setup MMTTY ->
Select the TX tab and set PTT & FSK to the desired port).

73,

    ... Joe Subich, W4TV
        microHAM America, LLC.
        http://www.microHAM-USA.com
        http://groups.yahoo.com/group/microHAM



More information about the WriteLog mailing list