[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
so.
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.
Cheers
John KB6SCO
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