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Messages - ZL/KF6VO

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1
HF Beacons / Re: Mixed CW / FSK beacon(?) on 4095.38
« on: October 17, 2023, 0022 UTC »
For Kiwis that have updated to software version v1.630 (most of them by now) I have added entries to the community DX label database for this beacon. Press the backslash ("\") key until the frequency scale shows "database: community" as shown in the attached image (red arrow on left). Then zoom in to 4095 kHz to see the labels.

There are two labels. Clicking on them will start the Kiwi CW or FSK decoder extensions preset for the beacon parameters. The Kiwi CW decoder is not so good. It requires a high SNR to function at all. The FSK decoder is pretty good though. As shown most of the FSK decodes fine. This was from a Kiwi in Sweden at 00:00Z. The right side of the labels have a clickable link that takes you to the HFU Wiki for the beacon.



2
Quote
Pardon the stupid question but before you excluded the masked areas form the SNR calculation, were they showing as SNR = 0 dB (which is my first thought) or are they showing as SNR = "huge dB", because the signal level is still available to the SNR calculation (despite the mask) and the noise in the masked area is basically zero?

Apologies for the late reply. I don't read here very often.

The answer to your question is "it depends". The SNR ranking algorithm takes a sample of all the waterfall bins (in dB), sorts them, uses the value of the 50% bin (median) as the "noise" level, and the 95% bin as the "signal" level. The difference (95% value - 50% value) is taken as the SNR. Prior to eliminating the masked bins this means that if there were enough of them to effect the 50% noise level value (after sorting) the SNR would become huge (noise level = -200 dB or something).

3
SDR - Software Defined Radio / Re: KiwiSDR future/replacement?
« on: July 15, 2023, 0111 UTC »
I have added a new URL parameter "1hz" which will be available in the next release (v1.620). So for a Kiwi where you don't have admin privileges you can say something like random_kiwi:8073/?1hz or random_kiwi:8073/?other URL params&1hz

Yes, there should be something in the user interface for this. But any changes to the UI are waiting for a major redesign. This URL change took me about 10 minutes to implement and test.

4
Quote
The only sense I could make of those is that they're manipulating SNR calculations.

After a while we realized this was a bug. So the masked areas are now excluded from the SNR calculation.

Regards,
John, ZL/KF6VO
KiwiSDR

5
SDR - Software Defined Radio / Re: KiwiSDR future/replacement?
« on: June 21, 2023, 2054 UTC »
Quote
Which is curious because he keeps cranking out software revisions.

Yeah, I should really stop. But it's tough to break the habit after 9+ years of running flat out. The other projects really need more attention than they're getting.

Parts are starting to become available again (except for one which has very unfortunately gone EOL). But now at about 2.5 times the previous cost. Can you imagine what would happen if a renewed Kiwi doubled in price? The backlash would make the effort worthless.

But parts and price are the least of the problems. I won't elaborate. But suffice it to say that restarting manufacturing/distribution is essentially impossible at this point.

Regards,
John, ZL/KF6VO
KiwiSDR

6
Sorry, I don't check this forum very often.

This is actually a software/firmware bug. I have a solution simulated in software that works. But the actual fix needs to go into the FPGA. And so far I have been unable to get that working. And I don't understand why. So I don't know when this problem might be resolved.

Regards,
John, ZL/KF6VO
KiwiSDR

7
SDR - Software Defined Radio / Re: KiwiSDR on Kickstarter
« on: April 15, 2016, 1810 UTC »
Yeah I'm glad too. András is a talented guy and I really want to see him continue with the next-generation SDR work he's doing. Also very pleased that Andrew Holme accepted our profit sharing offer for our use of his open source GPS work.

8
SDR - Software Defined Radio / KiwiSDR on Kickstarter
« on: March 17, 2016, 1949 UTC »
Well, we don't really need another new SDR. But this one is a bit different:

https://www.kickstarter.com/projects/1575992013/kiwisdr-beaglebone-software-defined-radio-sdr-with

I'd be happy to answer any questions.

Cheers,
John, ZL/KF6VO

(Sorry for the somewhat commercial post. I did ask Chris first..)

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