Exactly dB what. They are a measure of how far down
you are from when the front end overloads. With the AirSpy HF+
further calibration is not really possible last I knew. For most
other front ends calibration is possible and remarkably accurate
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On 20211223 09:41:40, Gedas wrote:
Tom, I do
not own an Airspy so I do not know but when you say below
-130 dB what are the units? dB what?
Are they an
absolute figure like dBm (which is what you need) or is it a
relative number related to ADU etc ?
Gedas, W8BYA EN70JT
Gallery at http://w8bya.com
Light travels faster than sound....
This is why some people appear bright until you hear them speak.
On 12/23/2021 11:15 AM, Tom Seeger
I wonder if you have both receivers connected to the antenna at
the same time? This can cause digital noise emitted from one
radio to be received by the other. Another good test is to
disconnect the antenna from each radio and replace it with a 50
or 75 ohm resistor and record the base noise. It should be less
than -130 dB. I measure about -135 dB on my HF Discovery at 277
kHz with a 250 Hz bandwidth.