[WT-support] SSB voice keyer question?

Olivier F5MZN olecam at f5mzn.org
Wed Sep 22 07:49:58 CEST 2004

f8crh wrote:
> Bonjour,
> Je viens de tester sur un tx et sa charge 50ohms!! le voice Keyer de 
> win-test excité par une carte son. En monitoring ça à l'air QRO!
> J'ai également poussé le vis à laisser branché ma pastille HC5 sur 
> l'entrée micro du PC et à exciter via un transfo d'isolement 600 ohms le 
> tx par la sortie HP de ma carte son > Ça semble également QRO en 
> monitoring!!

Do you mean that you always have the mic connected to the rig through 
the sound card? Maybe not a good idea, as if you must reboot your 
computer for any reason, you will not be able to transmit untill reboot 
is finished.

To minimize the RF feedback problems and have the best sound quality, 
the best way is to have a "phone" transformer IN and OUT of the sound 
card and some relays to commut between soundcard and real microphone. 
Use a plastic box, or isolated connectors (ground must not be common 
between soundcard and microphone).

Anyway I've no experience in SO2R using the soudcard as a voicekeyer. I 
usually have an external MFJ one, connected to the "main" radio. So 
that, the SO2R box only switch mic on "radio 1" or "radio 2". First 
times that I operated SO2R, I did even not have a switch for the 
microphone, the heil soundset was connected to radio 1 and an hand-mic 
was connected to radio 2. This solution is not very practical and there 
is a disadvantage: one can sometimes transmit accidentally on the two 
radios at once without realizing it, however it is a rules violation!

Olivier / f5mzn

More information about the Support mailing list