[GreenKeys] W1AW transmission

[Roy Morgan]

On Mar 18, 2009, at 7:33 PM, Ralph Mowery wrote:
...fired up MMTTy on the computer to see
>> how it would do.  No pleased at all.  ...
> Did you go in to the MMTTY program and make sure the filters, shift  
> and baud
> was setup correctly for the 170 hz shift and the frequencies  
> matched ?  Also
> make sure you do not over drive the sound card.

One trick that can sometimes fix all sorts of odd troubles is to use a  
transformer to feed the audio from the receiver to the sound card.   
Common grounds can set up noise and hum on the audio input that will  
make good clean operation impossible.

Radios like the R-390A can be run with the output transformer  
floating.. not grounded at any terminal at the receiver.  Similarly,  
the outputs (and inputs?) on the Dovetron can be run off-ground.

A small tube radio audio output transformer could be a good place to  
start if  you don't have any 600 to 600 ohm transformers.  Just run  
the normal speaker (low impedance) radio output to the speaker winding  
of the small transformer, and run the plate winding off to the computer.

As always, do report what works well for you.

Roy


Roy Morgan
k1lky at earthlink.net
529 Cobb St.
Groton NY, 13073