Batboard

Hi there I'm trying to record TX/RX Audio from an astro spectra. I have the TX working fine and the RX from the discriminator. Is there a way to get rid of the discriminator noise and have just the audio? I dont want to come off of the speaker out as it is volume sensative (from control head). I could put an AGC circuit in but if there is a easier way to loose the noise I would like that instead. -Thanks in advance

You need to pull the audio from the "high" side of the volume control. This will provide a constant level but should be filtered & muted. ( no white noise when no carrier present)

Hope that helps.

Bob

yan6 wrote:Hi there I'm trying to record TX/RX Audio from an astro spectra. I have the TX working fine and the RX from the discriminator. Is there a way to get rid of the discriminator noise and have just the audio? I dont want to come off of the speaker out as it is volume sensative (from control head). I could put an AGC circuit in but if there is a easier way to loose the noise I would like that instead. -Thanks in advance

Check the receiver section schematics. I believe a received-audio tap exist that comes off after the discriminator and filtering, but just before the volume control's electronic attenuator.

Failing that, you can try what worked for me for my audio panel in our van: Use a 1:1 audio isolation transformer across the speaker, and put the other half of the transformer into your recording system. The only downside is it'll be sensitive to the volume control setting.

Don't ever ground either Spectra speaker lead, no matter if it's Astro or Analog. You'll blow the audio chip in a heartbeat.

Happy hunting.