[Elecraft] K-1 Sensitivity

[alta]

What if a front-end stage has much wider bandwidth than the narrowest 
stage?  In this case, a strong signal could cause overload of the 
front-end stage.  And therefore, a highly-resonant antenna could 
prevent interference from a signal that is outside the narrowest 
stage.  In other words, I would think that problems can happen due to 
strong signals that are outside the bandwidth of the narowest stage, 
where a highly-resonant antenna might help.  Make sense?

... Reed, K7FLY, K1

On Thursday 14 March 2002 18:44, you wrote:
> Bill - You ask a good question
>
> "What happens to this discussion if we consider using narrowband
> (eg High-Q) antennas?"
>
> As long as all the stages in a receiving system are linear, from
> the antenna to the earphone (loudspeaker), the frequency response
> of the entire system is the frequency response of each individual
> stage convoluted together. What this means in plain language is
> that the narrowest stage will determine the selectivity of he
> entire system and hence the bandwidth over which the noise is
> integrated. I use 300 kHz for my FL-3 setting on my K-1. For the
> antenna to play a role, it would have to have a bandwidth narrower
> than this. For the ham bands, most antennas have a significantly
> higher bandwidth than this. At 7 MHz, an antenna with a Q of 350
> (corresponding to an antenna loaded with a very good low loss coil)
> has a bandwidth of 20 kHz, so the bandwidth is still determined by
> the receiver. At 160 M, the bandwidth is 5 kHz, and the receiver
> still determines the bandpass over which the noise is integrated.
>
> So, for the ham bands at least, the noise received is limited by
> the receiver bandwidth, and not by the antenna bandwidth. - Dr.
> Megacylce KK6MC/5

-- 
Reed White  -  ALTA RESEARCH  -  www.alta-research.com
Phone: 877-360-2582  -  Email: alta@alta-research.com