[RTTY] Windows 7 & Serial/USB Experience

[John Elsik]

I am no longer using the edgeport for fsk keying.  I now use a MicroHam MK II.  But originally I did use it for FSK keying.   I did not use EXTFSK.  If I remember correctly I am pretty sure it was off TxD.  I now use the edgeport for accessories such as amp, rotor, wattmeter, etc.
73 wa5zup


Date: Wed, 10 Feb 2010 10:12:17 -0500
Subject: Re: [RTTY] Windows 7 & Serial/USB Experience
From: david at levinecentral.com
To: ve3iay at storm.ca; wa5zup at msn.com

I am not using EXTFSK. In MMTTY on the TX tab, PTT & FSK is set to Com5 which is the 2nd serial port assigned on the Edgeport/8 unit. I do not have EXTFSK selected in MMTTY, On the Misc tab in MMTTY I have Com-TxD (FSK) select as the Tx Port option. 

I think that means I'm not using EXTFSK but if there's a specific question/answer I can give that further clarifies it, let me know. 


WA5ZUP also uses the same device so we can ask him what his settings are in MMTTY. I've copied John on this email as well. 

David


On Wed, Feb 10, 2010 at 9:57 AM, Richard Ferch <ve3iay at storm.ca> wrote:

David,

That's a very nice post on the Edgeport 8 serial adapter. However, there is one key piece of information that you didn't make clear. This is whether or not the device keys FSK RTTY with MMTTY without using EXTFSK.

As you noted in your post, almost any USB-to-serial adapter should work for basic CAT control. The exception appears to be that some adapters do not work so well at low speeds; the advice that I have seen is that if an adapter doesn't work for CAT and your radio is capable of a higher baud rate than you were using, try a higher speed.

Likewise, almost any USB-to-serial adapter should work for simple PTT switching (usually using the RTS line). If someone found one that didn't, that would be unusual and worthy of note. If an adapter works for PTT, it should also work for CW keying (usually on DTR), since the mechanism is the same.

For FSK keying, any adapter that can do simple PTT switching should also work with the EXTFSK plug-in for MMTTY. EXTFSK will work with almost anything, even parallel ports. EXTFSK can do FSK keying on any of the TxD, DTR or RTS lines, just depending on where you have your hardware interface connected.

The function that almost never works with USB-to-serial adapters is direct keying from TxD on a serial port (through a keying transistor or optoisolator, of course) for 45 baud RTTY using the 5-bit Baudot code, but without using EXTFSK. Many adapters do not support 5-bit codes, and many do not support baud rates that low. Indeed, I am not sure whether there are any USB adapters that will run with operating systems newer than Windows 98 and that will do 5-bit codes at 45 baud without using EXTFSK (or Writelog's built-in equivalent). If you can definitively report that the Edgeport adapter will key FSK RTTY correctly from MMTTY without using EXTFSK, that would be big news and definitely worthy of adding to the list at <http://n1mm.hamdocs.com/tiki-index.php?page=Interface+Devices> . The problem with this list is that people contributing to it don't make clear all of the details, e.g. whether they were using EXTFSK or not, and what baud rate they were using for CAT. Without these details, the information is not complete.

The issue with Prolific chipsets is a more complicated one. In Windows XP there is a problem with the Prolific driver that only seems to show up in software that is written in Visual Basic (like N1MM Logger). Apparently there is an interaction between the Prolific driver and the Visual Basic I/O code that shows up in a variety of subtle timing-dependent ways. This problem probably also exists in newer versions of Windows; the number of reports of problems with Prolific drivers seems to be getting worse, which I suspect correlates with the increased number of people using Windows 7. I think Joe W4TV is the expert on this issue.

73,
Rich VE3KI