Archive
 
 
  Topic: Mic Gain on Digital Modes (2 replies)
#1     Fri Dec 15, 2006 11:10 pm
N9BUB
Bedford, IN
 
Join Date: Dec 2006
Posts: 3
Subject: Mic Gain on Digital Modes

Being new to CQ100 I am trying to learn the opertion ... on HF I am strictly a digital op... RTTY, PSK and others ... I have made 3 PSK contact on CQ100 and assume that the same audio principles apply here as on HF with regard to soundcards ... If they do I see a awful lot of "overdriving" ... the traces are bright orange ... and the copy is not always good... almost like QSB on HF ... I am only running a minimum of mic gain .. agn assuming it is equal to ALC on a transciever ... anyone ????? are we headed in the right direction ????

TNX
de N9BUB
Dave
__________________
#2     Sun Dec 17, 2006 3:24 am
JA1SCW
Atsugi, Japan
 
Join Date: Nov 2006
Posts: 10
Subject: Mic Gain on Digital Modes

I would like to recommend the followins to realise better S/N, which will give a good reproduction of letters.

1, Use Mixer or Line IN/OUT with 10:1 ATT instead of Mic. (Never use Mic)
2, Keep sound level less than S=9 on your S meter during TXing.
3, Keep sound frequencies lower than 1Khz. Lower is better!

Even with the above setting, due to packet loss as nature of Internet, we sometimes encouter unpredictable garbles. However, most of cases the gaps genarated by garbles can be filled and a hundred percent understanding of message may be possible.

73! de JA1SCW Satoru
__________________
#3     Thu Dec 21, 2006 11:24 am
W0SDG
Apple Valley MN
 
Join Date: Oct 2006
Posts: 101
Subject:

"I am only running a minimum of mic gain .. agn assuming it is equal to ALC on a transciever ... anyone ????? are we headed in the right direction ???? "

Dave,

Do not treat the mic gain as you do ALC on an HF rig. As suggested in the previous post, run your signal at S-9 or S-10 but not more then that. It has been suggested to run the tones at 1000 Hz or a bit lower and that does increase IMD and decreases noise level as also suggested by Saturo. I hope to meet up with you around 14.070 some day.

73's,
Steve - W0SDG
Apple Valley MN

P.S. Use your soundcard faders to adjust your audio levels and not the controls on the rig.
__________________




Copyright ©2013 Cormac Technologies Inc.