[R-390] sensitivity

[Roy Morgan]

> ... sensitivity on all bands  as .07uV.  So the tightest filter in this
is 300hz.  So now we are  talking incredible receiver  right?  I  have my
suspicions on that.

Russ,

Claims of receiver sensitivity very much below one microvolt should be
regarded with suspicion.  Some of the factors in making such measurements
are:

 - actual input impedance of the receiver with respect to the test signal
source impedance
 - method of predicting the receiver input signal level
 - possibility (likelihood!) of leakage in the test signal generation
system at such low levels
 - bandwidth of  the receiving system
 - overall measurement system quality and capability
 - eagerness of the operator to proclaim astounding performance for his
receiver.

I know a fellow who owns a Ferrari Testarosa automobile.  I think it can go
nearly 200 miles per hours.  He seldom gets a chance to do that.

Bob Camps just-posted comment relates directly:
"If you are dealing with an HF radio below 10 MHz, none of this is all that
big a deal. Any time or place
you would ever *use* the radio, the noise into any rational antenna is well
above the KTB
noise floor."

Now, I'm going to go refresh my memory about the meaning of "KTB nose
floor".

-- 
Regards,
Roy

Roy Morgan
k1lky since 1958