[TenTec] Orion 566 Scratchy Audio with Sweep

[Howard Patterson]

I have a new development with my Orion 566.  I'm hearing a loud cyclic
scratching sound in the headphone audio when the Sweep is enabled.  The
scratching sound has a repetition rate of about 2-3 per second.  The rate
changes a little between modes and slows down incrementally when the HW NB
is on, DSP NB is on and Notch is on.  With all those functions on the
repetition rate is about 1/sec. It appears those same functions also slow
down the sweep a bit so that probably explains the change.  It also
practically stops when the VFO knob is turned.the sweep stops updating.
Speaker Audio and Aux Out are not affected. The amplitude of the scratching
sound isn't affected by the Main or Sub AF controls.   I've done a Master
Reset, RAM Clear and reloaded V2.044A with no change in symptoms.   From the
Audio Menu selecting Binaural Rx on the Main RX reduces the amplitude and
rep rate of the scratch a lot.  I can't detect any change associated with
AGC or Bandwidth settings.  

 

The behavior suggests it may be a hardware problem.  Sweep and audio
processing are common on the A7 Board.  Anyone ever bumped into this problem
before or have any ideas?  

 

Thanks / 73,

Pat, W5VY