Noise level variation AirSpy HF+


Jorge Garzón Gutiérrez <iberiaDX@...>
 

Hi,
Happy New Year to all!
My main receiver is a modified AirSpy HF+ (LW enhancement) and I've noticed something that puzzles me.

When I launch Console V3 and then I open my HF+ without switching on the Miniwhip amplifier, I get signals (just stronger ones) with a very low bed noise level. Then I switch the amplifier on and the rest of the signals on the MW band appears with a reasonable low noise level as I live in a quiet rural area. 

But when I first switch the MiniWhip amplifier on and then I launch the software and then open the HF+ receiver, the signals are there, but the bed noise level is higher by, saying... 15 dB, so the S/N is worst than before.

Why is this happening? Supposedly the noise must be the same in the system, but it is not!

Any explanation?

¡Gracias!
J

Jorge Garzón Gutiérrez "IberiaDX" 
(EB7EFA · EA1036 SWL · BDXC Member 1409) 
QTH: IN83ag / 43º15' N · 03º56' W
San Roque 95, casa 5 (Villasevil)
39698 Santiurde de Toranzo (ESPAÑA - SPAIN)
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Blog: IberiaDX  · Twitter: @IberiaDX

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