[Elecraft] XV50 cooling

[Geoffrey Mackenzie-Kennedy]

Would that not depend on whether or not the source impedance presented to 
the input device has been optimised for lowest noise figure or for optimum 
power transfer? If the former then the question arises how rapidly does the 
noise figure change with small deviations from an optimum noise "match", 
even if the effective loaded Q of the input circuitry is suitable to pass 
the six metre band.

I agree that the noise figure need not be very low for terrestrial 6m, but 
6m EME requires much lower noise figures when looking away from manmade 
noise sources.

73,
Geoff.


Tom W8JI wrote:

> I would think the major concern would be elevated noise or
> change in the first stage's semiconductor device parameters
> from the receiver's input device temperature increase, not
> from tuned circuit drift or PA noise.
>
> I can't imagine a tuned circuit wide enough to pass six
> meters drifting so far as to change sensitivity, or really
> any meaningful change on a band like six meters.
>
> 73 Tom