[RTTY] FSK interface circuit troubles

[Alfred Frugoli]

When I had the first circuit built I tried reversing the keying on the
"modem" (in this case software) end.  What resulted was a very hard to copy
signal (as tested sending from 1 rig to another in the shack - with
appropriate attenuation of the signal of course).

73 de Al, KE1FO

-----
Visit my amateur radio contesting blog at ke1fo.wordpress.com.


On Wed, Dec 10, 2008 at 11:53 AM, Kok Chen <chen at mac.com> wrote:

>
> On Dec 10, 2008, at 12/10    6:43 AM, k0bx at arrl.net wrote:
>
> > The kenwood TS-940 uses a reverse FSK from everyone else.
>
> The FSK polarity in the Omni V and VI were "correct."  In their
> "normal" setting, the Yaesu transceivers I have used are also
> "reversed."   But the Yaesus have a way to change the transmit FSK
> polarity (a switch in the 990, a menu item in the 1000MP).
>
> In this case, couldn't the polarity switch be done from the modem end
> instead of at the keying driver?  The software that I use has
> provision for reversing the FSK keying (although being an AFSK user,
> I've never had to actually use it).
>
> 73
> Chen, W7AY
>
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