Confirming what I need for a Kiwi 2 board
Good day. I have been gifted a KiwiSDR 2 board (nice friend), but without a beagle board.
I want to get this up and running as a proper Kiwi :). If I am reading everything correctly I would need to purchase a Beagleboard, such as this one that I can get in Canada - https://ca.robotshop.com/products/beagleboard-beaglebone-green-development-platform?gad_source=1&gad_campaignid=20159687494&gclid=Cj0KCQiArOvIBhDLARIsAPwJXOYavstnfZsgYHyeNFdMcG8V-cGHl1dLUi_vF3oRB3S-f9iQfvUe36kaAq6wEALw_wcB
A 5v power supply
and load the software from github. https://github.com/jks-prv/KiwiSDR onto a microsd card that can be used to flash/program the beagleboard? (not sure exactly how to do this but I am sure it is not too difficult)
This all correct or am I missing something? Don't want to fork out money on a board until I know I am looking at the right board and steps to follow.
Thanks for any input.
Scott (VA3XA)
Comments
Yes, that's the board. There are others that are slightly different. And some of them will not work for various reasons. So get the one in the link.
Instead of Github follow the instructions for downloading the software image to an sd card given here: http://kiwisdr.com/info/#id-net-reflash
Make sure your power supply and cable (important!) follow the guidelines given here: http://kiwisdr.com/info/#id-power
Consider getting one of our SDR protection boards if you live in an area with lightning storms that might damage the front end of your new Kiwi-2: https://kiwisdr.nz/products/sdr-protection-circuit
Thank you very much for the clarification and links. I was reading some of the posts about the power issues so was already making sure the one I found was correct :).
Does Kiwi sell the BBG with a preload? Did not see it on the webpage anywhere, would be happy to support Kiwi as much as I can.
Cheers!
Scott (VA3XA)
It would be best if you try making the sd card first and see if you can get through that procedure. We don't sell the BBG-only pre-loaded with software. I'd have to get our logistics guy to make one up. Then there's the shipping from here (DHL US$40).
Thanks for the guidance JKS, up and running! http://21263.proxy.kiwisdr.com:8073
Great. That was fast! Nice receive spectrum.
Thanks. I was surprised how fast the beaglebone shipped out of Montreal. A few hickups with the flashing (I had a bad microSD card) and it would not reflash with the Kiwi board in place, once I removed the board, it flashed fine. Could have just been my finger/pen not fully pressing that buried button but there was a hoot of joy when the cyclon headlights started. Cheers.
Your 580 kHz AM monster could probably do with a little suppression. I think I can hear IMD from it even in the noise at upper HF, which otherwise does have a little but not terrible line related/SMPS component.
A notch to get that -21 dBm signal 6-10 dB lower might help improve things even more. I suspect it's modulation peaks are responsible for some OL. Then maybe sorting out the ingress for the main's related lines that remain might get you near your ITU regional limit.
As a temporary measure, just try adding say 3dB attenuation, or just enough to stop the red OVE indicator from flashing.
I don't think you will need that much attenuation to improve things significantly.
Regards,
Martin
Yes, 580 CFRA is a noisy bugger. Runs 50k during the day and 30k at night but I think they are rather lax on lowering that power at night. Their transmitter is less than 20km's away. Good idea on building a notch for it - my next project maybe :). Have added 3db attenuation to see if it helps at all, but you did hit the worst part of the night.
A notch rather than just flat extra attenuation could have a slight advantage in that since this AM signal is by far the big pole in the tent, knocking only it down might get the ADC down to where the top MSB isn't getting exercised. Keeping aggregate levels 12-15 dB below OL has an advantage that ADC nonlinearity is less of a problem - possibly resulting in a couple of dB of lower noise floor at the low end of the range where a Kiwi (at HF) generally can benefit from it.
Not a big deal but as a system is improved, it's eventually the 1's and 2's of dB that make it better. Probably the spread main's related QRN is a bigger problem at present so addressing it might be the first step.
Thanks for the input, I did order an AM notch filter this morning, should be here tomorrow and should knock things down.
Hello,
I'm listening to your receiver from Nouvelle-Aquitaine, France, Trémolat. The computer part, the stream, is very stable; that's already excellent. Now we need to improve the RF section and especially increase the gain on the shortwave band. First, eliminate all the electrical interference that travels from band to band: power supply issues, grounding problems, ground loops. You need to work on all these avenues very meticulously.
A filter around 580 kHz is essential. The strength of the received CFRA station and its proximity prevent good reception. It completely overwhelms the signal. Building such a notch filter is not very complicated. The filter offered for sale gives very good results.
Best regards, Philippe
As an AM DXer, I'd suggest just applying just enough attenuation or building/buying a notch filter for 580 kHz. 5dB attenuation isn't bad. Many great KiwiSDRs have been fitted with AM BCB filters that wipe out the AM band entirely. Great if you're only interested in shortwave and the ham bands, but these Kiwis are very useful for content matching when trying to DX stations that are local/semi-local to the remote Kiwi.
I see you still have your AM channel spacing set to 9kHz, you can change that by going to the "Config" tab on your admin panel and setting "MW chan" to 10kHz.