Mark S. Holden wrote:
Margaret von Busenhalter-Butt wrote:
snip
That would be very kind of you, Mark. I'm just thrilled by your
desription of its audio quality. Exactly what I want. I wonder if
someone could remove the MW attenuation.
Thanks,
Margaret
Hi
It is the sort of radio you can listen to for hours at a time without
listener fatigue.
The manual indicates sensitivity is 1.5uv max for Am, and .35uv max for
sideband. (at 10db (s+n)/n ) It just says sensitivity is reduced below
1.5mhz
The radio has half octave filters on the input - a very quick Look at
the schematic leads me to feel you could adjust or eliminate the
attenuation by tweaking the value of a 470 ohm resistor.
Dynamic range is rated at 125db.
Near as I can tell, two of the keys to good audio quality are dynamic
range, and wide filters with steep skirts.
My AOR ar7030+ also has good dynamic range, and the sideband filter I
use with it is a 3.24khz crystal filter intended for a Racal 6790/gm.
It has a shape factor of 1:1.33 The radio reads it as 2.9khz.
As a follow up, I had a friend sweep his 550 - he found no measurable
difference in sensitivity between 200khz and 2mhz.
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