Vince,

Many thanks to you and the small team that worked with you to put this together!

This is an excellent, well-organized, summary of the data and of an approach Apache owners can use to significantly improve IMD performance and improve the accuracy of the DUP display while transmitting. While ...

To minimize latency, CW is generated in the FPGA, i.e., in the radio hardware. TUNE along with all other "test signals" are generated in the DSP software, in the computer. Therefore, CW and TUNE are not available at the same places in the architecture. If the CW sidetone were sent back from the ...

Richie,

I think the PS BPF warning is a good idea. Thanks for planning that.

BTW, thanks for all the continuing work and dev_5.

Warren NR0V

Reason for bypassing BPF for PS transmit: We run a high feedback level to use basically the full dynamic range of the ADC. This high signal level can produce passive Inter-Modulation Distortion in the inductors of the bandpass filters. This distorted feedback then degrades PS performance. This is ...

Hi Stefano & All,

I'm looking at a possible adjustment that might allow better access to signals when the signal-to-noise ratio is very low. If that works out, you'll hear more about it later.

With regard to "frequency domain" processing, if you search for "frequency domain" or "time domain versus ...

I’ve had multiple requests for more information on the operation of the new “Trained” NR2 mode. I’ll give a very brief summary here.
This mode, like other NR2 modes, operates in the frequency domain, i.e., after performing an FFT on the incoming data. In each frame of data, each frequency bin is ...

The correct value of 'SetPk' is ONLY dependent upon the firmware in use. It does not depend upon the coupler, or any other hardware or parameter. As of this date, there are three different values of 'SetPk':
ANAN-G2 (protocol_2): 0.6121
All other protocol_2: 0.2899
Protocol_1: 0.4072

Thetis should ...

The curve shapes are very reasonable and the dotted blue and yellow lines are fine. To calibrate, PureSignal collects samples as the two-tone (or voice) goes up and down through the range of possible amplifier outputs. Since these are "samples", they are distinct points, not a curve. A two-tone is ...

Hello Juha,

There are many ways to do things in DSP and these are not simple topics. I welcome your involvement.

73,
Warren NR0V

Hello Juha,

The EQ and CFC do not operate at RF frequencies; however, they also do not happen to audio samples in time. When I say "in the frequency domain," I mean that we have taken a sequence of audio samples and done a Fast Fourier Transform (FFT) on those to convert them to a set of frequency ...

Hi Juha,

In the example I gave, the response below 1000Hz and above 1500Hz will depend upon other frequency points at which you may have specified the compression profile. First, I should explain that there are two "hidden" frequency points -- one at 0Hz and the other at the maximum frequency ...

Hi Juha,

With the CFC you can create a wide variety of compression profiles, including emulating a compressor with a small number of bands. The key here is to remember that the compression profile will be interpolated between the frequency points that you specify. So, for example, let's say you ...

James,

That's a most interesting situation. It would seem that something is distorting segments of the signal waveform and SNB is then correcting that distortion when it's turned on. SNB has the seemingly magical ability to correct/replace entire segments of a waveform. If you're not familiar with ...

Greetings All,

There are a few items on which I'd like to comment:

1. Carrier level with PureSignal ON versus PureSignal OFF. As you know, PureSignal causes your analog amplifier chain to respond linearly, i.e., when drive is 25% of max, output is 25% of max, and when drive is 100% of max, output ...

Hi Jay,

You ask an interesting question and one with a somewhat complicated answer. In some sense the current implementation is already a CFL in that there is a hard-limit that is carefully and gradually imposed on a bin-by-bin basis. However, this must be considered along with two other factors ...

Hi Jay,

Some information can be found in the release notes:
<https://github.com/TAPR/OpenHPSDR-PowerSDR/blob/master/ReleaseNotes.md>
Scroll down to the 3.4.1 release.

However, I'll explain a bit more here. The traditional approach to multi-band compressors uses filters to separate the frequency ...