LimeSDR-mini bellow 30MHz

I testing my new LimeSDR-mini. I testing with CubicSDR and Console v3. With Console v3 and CubicSDR v0.2.3 working stable but not with newer versions. I tried to receive signals from 10 MHz, but any signal on screen. If I tested with signal generator, then I could see that the receiver started to work just above 30 MHz. I think LO does not work. Can it be changed on settlements or my equipment is bad?

Joe

Bellow 30MHz your app need to use NCO algorithm. Practically it is UP converter and converts 0.1-30MHz above 30MHz with NCO.

Could you help me more carefully? I’m beginning to do this.

I’m not sure how CubicSDR works but SDRconsole v3 automatically sets NCO.


Without BPF FM stations are very strong.

I tried ConsIole v3 ver 3.03 and 3.01 on Windows10, but nothing on 14MHz. What version do you use?
Joe

3.0.1 on Windows 10 64bit. Is your mini receive anything above 30MHz? FM broadcast stations? Any TV (DVB-T or analog)?

Above 30 MHz is all OK. Above 30 MHz it work. I have problem only bellow 30 MHz.

Is your mini board have latest GW?

I do not known. I bought a month ago. In LimeSuite after GET INFO I get:
Device: LimeSDR-Mini
Expansion: UNSUPPORTED
Firmware: 5
Hardware: 0
Protocol: 1
Gateware: 1.26
Gateware rev: 1.26
Gateware target: LimeSDR-Mini

Some for Control port and Data port.

Your mini GW is latest - 1.26
Try several times to change bandwidth in SDRconsole while receiver is on.

Sorry, this did not help. I tried many times, but nothing bellow 30 MHz.
Joe

Try to reflash gateware.

Joe
The specifications for the Lime Mini clearly state that the operational bandwidth is from 30 MHz to 3.7 GHz. So there is no direct solution to seeing signals below 30 MHz.

If you absolutely have to have a look at signals below 30 MHz I would suggest using an upconverter with the LO sourced from the TX channel.

You will also find that reading and understanding the ARRL Radio Handbook to be VERY helpful. You will find many solutions illustrating your delima. It’s a very easy problem and solution. However, your going to need to solder up a few components.

There is a lot to know, so be kind to yourself.

Most importantly, don’t be fooled by the relatively low price of the Lime Mini. 10 years ago you would have paid 10’s of thousands of dollars to have the same functionality. It is a very sophisticated device.

73

Then maybe, Crowd Supply should stop saying it’s working from 10MHz (see attached screenshot).

Also, LimeSDR-Mini - Myriad-RF Wiki just write « TBD » for the « Continuous frequency range ». So i’m not sure this is this clear.

LimeSDR Mini works just fine below 30MHz. Mini can work even below 10Mhz but with reduced sensitivity and reduced output power because of inadequate matching network. At the moment there is no min frequency limitaion in Limesuite library. Both LimeSDR devices uses same LMS7002M chip and biggest RF differnce is antenna matching network. Because huge frequency spectrum coverage some compromise are made. Unfortunatelly HAM radio bands below 30MHz are not commercially attractive like 3G,4G,WiFi or other hot bands for professionals or academic researchers.

Just for illustration what to expect from RX inputs…
SDRPlay RSP1 up
and
LimeSDR USB LNAL modified, down…
Sweep 0.5 to 7.6 MHz, -65 dBm

This few pictures are only for demonstration how LimeSDR-mini receive below 30 MHz with simple wire dipole, 4 meter high under attic:
(SDR# 20m band screen)



(WSJTX with FT8 mode)

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It is very-very nice, but I do not have your controller, is it possible to get it?

Joe

@yt7pwr
I am interested to know more about your setup.
Do you have your LimeSDR-mini setup to communicate directly with WSPR-X? Do you have SDR# as a middleman program between LimeSDR-mini and WSPR-X?

I will tomorrow upload to my github account entire project of LimeSDR controller.

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