[AMRadio] Ranger Audio

John Lawson jpl15 at panix.com
Tue Nov 14 23:29:01 EST 2006

  Jack - here's a quick set-up that will give you 'real' data - as opposed 
to the Aural Objectivity of your fellow hams.

   Use your light-bulb and SWL recieveras before.  Hook a VTVM to the 
reciever's output - speaker, headphones, no matter as long as you can get 
a comfortable reading of the audio output.

   Hook an audio generator (thru a suitable resistor 'pad) to the Ranger 
in place of the D104.

   Put the generator at, say, 1 KHtz, tune up the Ranger, set the 'audio' 
control for a good reading on the meter, and then set the reciever audio 
to give a "midscale" reading on the VTVM. (Don't drive the Ranger too hard 
- this will be a long period of "key-down" operation at 75 or 100% 
modulation. Be nice to them 1614s....)

  Now, without making any adjustments whatsoever, tune the generator freq 
down to, say, 50 htz., and note the VTVM reading.  Then up to 60 Htz, note 
the reading. Then 120 Htz, then 240, then 480 etc etc up to about 4K or 

   If you really want to get 'scientific' - do the same test but with the 
Kenwood.  That will 'calibrate' what is due to the Transmitter and what is 
due to the Reciever audio bandpass characteristics.

Now you'll have a real idea of what the Audio bandpass 'looks' like.


John  KB6SCO

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