Topics

AUDIO FILTER

dave
 

hello men has anyone fitted the Sotabeams Laserbeam digital filter (cw) to the ubitx  v5 as an integral part, rather than used as a stand alone filter   many thanks   Dave c

Dan Pflugrath
 

After watching a talk on DSP I am considering trying it in my bitx.  One caution is  the level of audio required on the input.   I currently run one bitx with the NESCAF which is an amazing filter for CW but had to feed it with the audio output from the bitx.  We may need a stage of amplification ahead of the sotabeams DSP filter

 

I have a version 4 and ran my audio feed directly into the sota beams dsp and then added an audio amplifier following the dsp. Version 4 has notoriously low audio output on its own. So, I suspect when using the dsp with version 5, you may need to insert the dsp in the audio chain prior to the final audio amp to prevent overdrive clipping.

David Posthuma
WD8PUO

 


From: bitx20@groups.io on behalf of Dan Pflugrath <dpflugrath@...>
Sent: Sunday, November 24, 2019 2:57 PM
To: bitx20@groups.io
Subject: Re: [BITX20] AUDIO FILTER
 
After watching a talk on DSP I am considering trying it in my bitx.  One caution is  the level of audio required on the input.   I currently run one bitx with the NESCAF which is an amazing filter for CW but had to feed it with the audio output from the bitx.  We may need a stage of amplification ahead of the sotabeams DSP filter

howard winwood G4GPF
 

just integrated a sotabeams af filter in my ubitx v5, you need the lm386 amp circuit sotabeams show in their instructions to provide audio to the speaker.
the original lm386 on the main ubitx board provides the input to the sotabeams filter.
this means you now have 2 volume controls, one controls the input to the filter, i.e set level, the other controls the final audio output.
just ordered a dual coax (concentric) 10k pot prom China, as I do not have room for two separate pots.