jreid@aloha.net writes:
<< I do get the noise, whether the antenna input
terminal to the Omni VI+ is left "open" or terminated in
50 ohms. BTW, the S-meter reads zero deflection. And,
yes, perhaps even in the background, below or at the level of
rigs RF stage internally generated noise, I can hear
a faint "whine". >>
There is a big difference between noise due to the receiver sensitivity (with
antenna connected) and noise generated internally (antenna disconnected, DSP
and LP off). Again, what we are concerned (complaining, or trying to improve,
rectify) is the internal noise generated by the IF stages after the crystal
filters. This noise is characterized by high pitched noise that is detected
and amplified by the audio stages (annoying hiss). The possible solutions
could be adjusting the working parameters of IF amplifiers, or adding
filtering before the detector.
The point is, your multi $k rig should be dead (or close to) quiet when
antenna is not on or ant input is shorted out.
When you connect antenna and hear noise, you got sensitive receiver (or noisy
neighborhood). We are not talking about that situation at all. THAT is normal!
Aloha and Sayonara
Yuri, K3BU
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