G8JNJ

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

Ah OK...

Personally, I wouldn't recommend that model, but let's see how it works for you, when used with your antenna.

I'm not sure what device the Noolec is using, but I guess it will be something like the Qorvo QPA4363A.

Rather than issues with MW stations, it's more likely to be issues with possible overload from any strong FM broadcast stations, or other VHF transmitters that may be around your location.

The reasons I suggested a PGA-103 based amplifier for your application are, good IMD performance, low noise figure and rising input impedance, which helps improve signals on the LF bands, especially when using a short antenna. The current consumption is a bit higher at around 100mA. Noolec may have chosen a lower power consumption device, so that it can be used with the limited current available from sdr's with built-in bias tees, many of which have a maximum current rating of around 50mA.

But experimentation is all part of the hobby, so just try it, and be sure to report back with your findings.

If you need any specific help, send me a PM.

Regards,

Martin

I don't think you will be able to get in using WinSCP.

I'm experiencing similar problems since updating the OS version, and WinSCP doesn't provide the option to log in as su. I seem to remember reading a thread about it but can't find it.

Also, with Debian 11 to enable root login, you can add a line to the sshd_config file in /etc/ssh/sshd_config:

Edit the file as root using nano /etc/ssh/sshd_config

Add the line PermitRootLogin yes in the Authentication section

Save the file

Restart the SSH server using service sshd restart

I swear the Linux folks move the goalposts purely to keep us muggles at bay, but if you do find a solution, be sure to tell us, as this is turning out to be a real pain.

Regards,

Martin

I'd also suggest emphasising the "works straight out of the box" aspect of the KiWi.

One competitor is making an attempt at this, so far unsuccessfully, but the majority of previous competitors have not been able to achieve this. Other options, such as OpenWebRX (moderate pain) or PhantomSDR/Plus software (really painful), are still in their infancy, and require a fairly extensive knowledge of Linux to get running initially, and then update and maintain.

Regards,

Martin

This is a thorny subject, and I could write a thesis on it. I have already made my position clear to John, but I'll raise a few points here to further the discussion.

Open-source / FOSS is generally a great concept, kids these days like having stuff for free. Music streaming is perhaps one of the best examples. However, the problem is how to make money from it, and many small artists are still arguing about that one.

The principle of collaborative free software is good, as long as everyone contributes, less so when one person does the work, and everyone else sits back and makes use of it. In the workplace, most people know who is actually doing the bulk of the work, and who is just doing the bare minimum, or "clock watching".

John is in a difficult position, where the Opensource software, supports hardware, which he sells to make an income.

When you buy a KiWi you also get for free, a superb level of support from its enthusiastic developer (John), and unfortunately competing products like this, building on his work, but sold at low cost, for short term gain, will impact the long term survival of his business, including the other services he provides, such as TDoA, which run on his servers, at no additional cost to users.

By contrast, most of the previous KiWi clones have fallen by the wayside, despite assurances from the companies producing them, that they would not stop supporting their products. They try to make a quick "buck", then loose interest as sales decline.

The current competitors have used the KiWi code, and introduced some innovations in their own product, but these really only benefit the competing hardware, they do not directly feedback into the KiWi code, product or features. Their software is flaky, and response to significant bugs is usually patchy at best.

I don't think John can compete on the hardware side. Designing, building and selling hardware will always be difficult when competing against certain regions of the world. Low production costs, scale of manufacturing, circumventing import taxes and duties when shipped to other countries, and lack of respect for IPR, all add into the mix.

However, the time and effort he has put into developing the KiWi, since it's original fork from OpenWebRX, needs to be rewarded in some way, and I don't think that in future that can be achieved through the manufacture and sales of the hardware. Some way needs to be found to protect his IPR, provide a source of income, and cover the costs of him providing aftersales support, software updates, and the running costs of the services he provides for free such as TDoA and proxies etc. A subscription for support services, could be one way of achieving this, but in the meantime, protecting the parts of his code that he can, without infringing the Opensource parts, should definitely be considered.

Personally I'd risk doing this, and wait to see what happens, if someone objects then just fix the bit that is problematic, but in many cases it would be "the pot calling the kettle black", so I don't think it would be a major issue.

I'm all for respecting the law, and various formal or informal Open source agreements, however this shouldn't allow an individual to be taken advantage of, especially if they are good-natured and willing to go above and beyond what is required to make a profit, for the benefit of the community as a whole.

That is not fair, and should not be accepted by anyone with a social conscience, or sense of justice.

I could say an awful lot more, but this summarises my position, and I hope it will lead to a more meaningful debate.

Regards,

Martin