[TenTec] Re: TenTec Digest, Vol 14, Issue 68 - Sensitivity Issues

[K3BU at aol.com]

In a message dated 2/25/04 11:51:43 AM Eastern Standard Time, 
w1ael at mindspring.com writes:

“…But take that receiver to the ocean front, put directional antennas on 
it, use specialized receiving antennas and you will find that you NEED 
gain on low bands. Or beaming with good directional antenna north, away 
from the equatorial noise and try to dig those 10 W JA novices. You can 
use every uV you can scramble….”

“…you NEED gain on low bands….”    Let us not confuse GAIN with sensitivity!

OK, wanna be precise, please replace "gain" with "sensitivity", that's what I 
meant.


>>Yuri, the sensitivity test I suggest remains a valid one for your DX 
venue!<<
Nothing wrong with the test. The point is, if the radio is aimed at 
competitive hams, then it better have room and features to accomodate their needs 
inlcuding sensitivity on all and low bands. 


>>Perform it in that environment, under those conditions, and you might 
find that you can use greater sensitivity.   The ‘antenna on/off test’ 
pertains directly to the environment of the receiving site.  The 
overwhelming majority of urban, suburban, and most rural amateurs all 
over the planet do not have anything like the quiet situation you 
describe!<<

On the contrary. Pennants and flags and small lopps and slinky beverages are 
spreading like a wildfire, more people are coming to low bands and using 
specialized RX antennas with low gain, low signals but some directional properties. 
Putting crummy preamps to compensate for the lack of sensitivity defeats the 
glorious ability of modern radios.

>>Performing the sensitivity test I suggest really DOES YIELD VALID 
RESULTS FOR A RECEIVER AND ANTENNA SYSTEM IN ITS ENVIRONMENT.  To the 
extent that location, frequency, and antenna may mitigate atmospheric 
noise, a system that has maximum useable sensitivity for the vast 
majority of radio amateurs might be found wanting in a very rare 
situation.  Please accept my apology for not making that clearer.   The 
relatively noise-free situation you postulate is an “imaginary reality” 
for most designers and contest operators alike.<<

Here we go again "we know better" syndrome. I rest my case. 
That IC78000 is looking better and better. 

73 Yuri