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You only need sufficient attenuation to take the strongest broadcast stations down by just enough to prevent ADC overloads from occurring. I generally try to keep all signals across the 0-30MHz spectrum below -30dB.

If you have an existing band stop filter, with too much attenuation, you can connect a 1K ohm variable resistor between the input and output of the filter, and then adjust the value until you have enough attenuation to prevent overload occurring at night, but still allow some signals to pass through at a usable level.

Even on a receive site where I had strong signals from local medium wave transmitters, I've not had to introduce more than 20dB of band reject filtering to fix the problem. In most cases, a simple 10dB slope frequency / amplitude equaliser provides a good compromise.

This and other techniques have been discussed in many previous threads, so it's worth searching for those.

Regards,

Martin

I have said this before, but I consider the KiWi to probably be the best radio hobby related purchases I've ever made, and it has reinvigorated my interest in Short Wave listening, and utility monitoring.

Nearly every week I discover something new, or an enhancement that John has implemented. Which is in stark contrast to other developers, who often immediately dismiss legitimate requests from users and admins.

The TDoA function is a stand-out feature, that has made an otherwise difficult aspect of the hobby, IDing the location of unknown transmitters, become relatively straightforward.

I have recently swapped out my computer monitor from the 22" model I was using, to a repurposed 44" 4K TV, and it's a game changer. Being able to see a vast swathe of spectrum, in relative HD, is superb, and makes spotting unusual signals, or patterns of signals, very easy.

My sincere thanks to John for continuing to support the KiWi, despite the extremely difficult trading environment, and to all the others who have contributed in some way, it is much appreciated.

Regards,

Martin

In addition.

If you have more than the specified number of users trying to connect, the additional ones can "queue" to wait for the next free slot, or "camp" where they can "piggyback" onto an existing user and hear just the audio.

This is useful when you have a lot of users all wanting to listen to the same thing, such as a popular amateur radio net.

The maximum number of campers can be defined in the "Control" admin page.

Regards,

Martin

You can place attenuation ahead of an LNA to improve strong signal handling, but the amount of attenuation needs to be chosen carefully, to take into account the LNA gain and Noise Figure, in order to ensure that the overall system Noise Figure is not any worse than the basic receiver alone.

If you search though the forum you will find many posts on the subject of equalisers, filters and notches.

Here is one example

https://forum.kiwisdr.com/index.php?p=/discussion/comment/5723

For a more detailed analysis of how equalisation can be applied in order to reduce the noise contribution due to intermodulation effects without affecting the basic Signal to Noise performance, see if you can find a copy of this paper on-line.

https://digital-library.theiet.org/doi/10.1049/ree.1977.0028

Regards,

Martin