[WT-support] PTT on LPT Port - MMTTY

[Bob Wilson, N6TV]

On Fri, Sep 3, 2010 at 2:07 PM, John Wayman <g4drs at btinternet.com> wrote:

> When I had a play in SCC RTTY last weekend, I was unable to figure out a
> way to have WT key the PTT.
>

In RTTY mode, all PTT work is delegated to MMTTY, because only MMTTY knows
how long it takes to send an RTTY message.


> I am not sure I have understood things correctly, but it seems that MMTTY
> has no means of switching PTT via LPT port pin 16, and that WT does not
> bother with switching PTT when MMTTY is running.
>

Both are correct statements.  I am not an RTTY expert, but this web
page<http://www.g4zfe.com/rtty.html>explains how to use extfsk and
dlportio to do PTT via an LPT port in MMTTY.
Unfortunately it looks like extfsk only gives you the option to use Pins 1-9
(Strobe, D0-D4 and D5-D8) for PTT; Pin 16 is not an option!

Use a different dedicated com port for each radio to switch PTT - not my
> choice because PTT is all cabled up via LPT pin 16, and besides, who has
> that many com ports?
>

An easy hardware fix would be to make a plug or adapter that connects LPT
pin 9 to pin 16 instead of pin 16 to pin 16, and use that for RTTY.

Better yet, the microHAM router supports FSK and PTT via DTR on the same COM
port.  But it sounds like you are using AFSK.

Here's a quote from the MK2R manual (may also apply to your microHAM box,
but you didn't specify what you are using).

"PTT: The virtual port used for FSK can also support PTT (required by
MMTTY). When you use MMTTY,
select the PTT box and RTS will used for PTT"

So, I have a fully set up SO2R station for CW and SSB, all nicely cabled up
> (by my standards, anyway!), which I have to re-configure to run RTTY. Can
> that be right?
>

No, not if you use FSK instead of AFSK.  What radio are you using?  What
microHAM box are you using?

How have you got around this problem?
>

I use an MK2R+ with an Elecraft K3 in FSK mode, virtual COM5 for FSK and PTT
for Radio 1, COM6 for FSK and PTT on Radio 2.

Is it possible to have WT switch pin 16 on the LPT port during RTTY messages
> in the same way as it does on CW and DVK messages?
>

No, because Win-Test doesn't know how long to hold down PTT.


> How does it all work without fuss in Logger32? Is whatever happens there
> the answer to my problem?
>

Perhaps it uses Radio commands.  With the latest microHAM Router program you
can assign *two* virtual COM ports to the same radio.  Use one COM port for
Win-Test radio control, and use the other virtual COM port for MMTTY PTT via
radio command, perhaps.

73,
Bob, N6TV
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