[RTTY] FSK interface

[WS7I]

>On Wed, 5 Sep 2007 16:14:34 +0000, "A.Oskarsson" <tf3ao at simnet.is>
>wrote:
>
>>I was wondering what kind of FSK interface would be best for my ICOM 756PROII. I have seen the one that Don AA5AU describes on his page, or would it be better to use an optocoupler for this (like the one described by IK3QAR)?

Yes an optocoupler would be much better than the one that Don described and uses.  I also use one of those, however, I have a $29 serial card in my computer. The opto's primary use is to protect your serial card and has nothing much to do with hum.

If the transistor fails it will blow the serial driver and if that is on your motherboard/laptop/etc you could be in for an expensive repair.

If you have cheap serial cards then why bother.  I changed out to opto's back a couple of years ago when I bought a motherboard which had several serial ports on it.