A USB Audio "Null Modem" for Remote Mac Digital Ops

  • 2
  • Idea
  • Updated 3 years ago
Maybe I have too much time on my hands...

Not satisfied with MacBook Air phone and CWX operation from poolside, I built a little "null modem" for digital modes out of a "hamfest special" USB audio dongle. Removed the i/o jacks and installed a voltage divider (10k & 100 ohm) to bring the speaker level to microphone level. 

Works great!

I can run a digital mode application on my Mac laptop with DogParkSDR and merrily make contacts. Use VOX for transmit. Watch the levels to avoid over modulation and tripping the VOX during receive.

Windows machines, of course, have it easy with DAX and CAT!

Photo of George Molnar, KF2T

George Molnar, KF2T, Elmer

  • 1561 Posts
  • 552 Reply Likes
  • Like a happily mad scientist...

Posted 3 years ago

  • 2
Photo of Walt - KZ1F

Walt - KZ1F

  • 3040 Posts
  • 643 Reply Likes
Are the band virtually completely static where you are too?
Photo of George Molnar, KF2T

George Molnar, KF2T, Elmer

  • 1561 Posts
  • 552 Reply Likes
Been a pretty dry spell on the bands, for sure.
Photo of Tim - W4TME

Tim - W4TME, Customer Experience Manager

  • 9148 Posts
  • 3467 Reply Likes
Geomagnetic storms recently.  http://www.spaceweather.com/