[RTTY] Omni V and FSK

[Kok Chen]

On Thursday, April 3, 2003, at 05:05  PM, Ed W3NR wrote:

> Now , if I got this right, I use the Mark and Space jacks on the Omni
> instead of the Audio in, but do I use PTT or the RTTY Key to switch to 
> TX ??

When you transmit, there are two things you need to do:
	1) turn on the transmitter with the PTT connector,
	2) key (switch between Mark and Space) the RTTY key connector.

Basically, to use FSK, you need a) AF out from the rig to the sound 
card input,
b) PTT to the rig, and c) bi-level FSK keying signal to the rig.

> Audio out from the Omni is at line level and for MMTTY still needs to 
> go
> thru the soundcard.

Be aware that the output impedance of the Omni's line out is a true 600 
ohms
(emitter follower with a 600 ohm series resistor!).  Be sure that you 
don't load the
AF output down.  I think all sound cards have input impedances of the 
order of
many thousands of ohms, so you should be alright, but be forwarned (in 
case
you are going to use a pot to control the output level; use a pot that 
is at least
5 kohms).

73
Chen, W7AY