[R-390] sensitivity

[Bob Camp]

Hi

Once you know the noise bandwidth of the filter, the next question is:

“what is the S/N ratio used for the sensitivity measurement?”. This one is a bit easier.
If I use 6 db and you use 20 db, my data will be 14 db better than yours. 

A more rational way to measure sensitivity is to simply come up with the noise floor of the
radio. If you express that in db above the KTB noise, you get easy to understand numbers. 
A radio at 3 db is 7 db more sensitive than a radio at 10 db. A radio at -1 db is physically 
impossible. 

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. 

Bob

> On Oct 7, 2016, at 1:06 PM, <wb3fau55 at neo.rr.com> <wb3fau55 at neo.rr.com> wrote:
> 
> So OK guys,  the receiver in question is a Drake TR-7 and  said having been checked  for 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.
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