[RTTY] MMTTY-laptop problem revisited

[W5FKX - Don]

Thanks to the many that responded with very helpful suggestions to my 
problem ... it is now resolved!! Here is a brief run-down of what I did:

- first, I determined that it was NOT an RFI problem - the fact that the 
problem occurred at 5w should have been a solid clue, but then even w/o the 
rig on, MMTTY (v. 1.58) locked up after I clicked on the TX button.

- next, it was a question of eliminating problems in: USB port, XP, MMTTY, 
or USB-Serial adapter.

- one of the respondents suggested that I look at my good friend Don's 
(AA5AU) website regarding his evaluation of USB-Serial adapters 
(http://www.rttycontesting.com/usb.htm) and his other site (below). Don 
lives across town from me and I have often referred to his excellent RTTY 
info pages, but had been too wrapped up in the presumption of RFI to 
consider something else! There was some great (and worrisome!) info about 
many of the adapters on the market and their possible problems, but none 
that I could specifically identify as mine (a Manhatten Computer Products 
adapter purchased from BuxCom).

- a query to BuxCom about the ability of the UART in the adapter to handle 
5-bit Baudot got a terse (although, in hindisght, technically correct) reply 
to "set your software for FSK... In the program, it is NOT the USB2SC, it is 
your SoundCard software setup... FSK, NOT AFSK". As the software WAS on my 
list of factors to investigate, I decided to look at it first ...

- Off the AA5AU RTTY page (http://www.aa5au.com/rtty.html).After 
unsuccessfully trying all of the suggested settings in MMTTY described in 
"Transmitting FSK with MMTTY", I noticed another section entitled 
"Specifics -USB adapters, EXTFSK". That turned out to be the key ... a new 
plug-in that JE3HHT had for dealing with "external FSK" using a USB-Serial 
adapter for PTT.

- After downloading and installing the latest version of MMTTY (v. 1.65) 
along with the plugin (http://mmhamsoft.ham-radio.ch/mmtty/index.html) 
called EXTFSK, I tried it with my portable setup and ... it worked!! A quick 
check on 20m RTTY this afternoon led to Q's with UA6CA and 9A150NT.

- Finally, I found no problems even after removing the toroids.

Thanks to all who responded, and special thanks to Don for his great 
reference source. I'm now a happy camper (literally!). :-)

78,
Don W5FKX
Delta DX Association
http://www.qsl.net/ddxa