Where did the 100 KHz go?

Here’s a better screen shot of HF 5-15Mhz with just MN18 removed. The previous shot had gains all whacked and for some reason I had visual gain set to 5dB. This is a 1.4 board running under USB-2 at 10Mhz. You can still see some of the FM signals coming through across the frequency range.

-Freeman, N5FPP

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Linux with the latest LimeSuite code from github is much more disappointing. This could be something I did, or haven’t done. I can barely hear anything in 40m with all the gains maxed out. The screen shot of gqrx says it all :slight_frown:

-Freeman

I still cant get GQRX (pothossdr for windows) to work, it worked once now I can’t get any waterfall/spectrum to display using driver=lime,soapy=0, so i’ll stick with sdr-console now that its working good…

@Cornie I’ll pass your questions on to Danny.

@nn4f_radio thanks for sharing the annotated screenshot and photo! We’ll be providing a more pictorial guide and/or video next week. I’ll also run up Gqrx with the latest Lime Suite and see if we can find out why you’re not seeing the same performance with this.

@nn4f_radio @andrewback @n5fpp
See my post in the other thread. With the current SW it might work better with manual bandwidth setting.

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Hi, Andrew - thanks for the work you had done with the measurements and the numerous fixes to improve performance on HF (i.e. <30 MHz).
I exclusively backed the project to get in return a 30 MHz wide band of HF. The specifications promised a range from 100 kHz - not just “tunable”, but without restrictions in e.g. sensitivity.
It seems that the non-modified boards will not fulfill these specs, but the modified version will - more or less.
I don’t want to do the modification by myself. Then I would have to buy a (de)soldering set for SMDs, some ESD stuff and some parts plus investing a lot of time. Furthermore, I would risk to lose the guarantee plus CE certification. It
then simply becomes illegal to use this board at least in Germany. We had many house searches by police in similar cases, plus confiscations and penalty payments in the range of 6.000 US-$/case plus court costs.
This is a real danger, as I myself already had been target of two house searches after having been denounced by fellow hams. They proofed fruitless, as I am a ham by myself (and journalist, writing on science and technology) who can buy and use kits without a CE certificate. But this often isn’t known by the enforcements agencies, and I don’t know the situation in other countries. The law in Germany is quite clear: You cannot use such a device without a CE certificate if you are not a ham.
Having said this: Is is possible to do the modification by your company for those people who haven’t got the board yet (like me)? I would rather accept some more days/weeks of delay than to invest in tools and parts and time to get a brand new device working to its announced specs, losing guarantee and CE certification.
Your answer is highly appreciated. Best regards: Nils www.dk8ok.org

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I fully agree with what Nils said.
Andrew, I want to thank you for your great communication.
Where are you located geographically? For the jet lag compared to France.
Thank you for being present even on Saturday.
I regret that some messages are deleted, but I am glad to know that they are read and that they allow to advance and to see certain documents modified in final.
Best regards
Bernard

That looks pretty cool as well, haven’t seen that one before.
I do notice it is also a 12bit radio so it too is more akin to LimeSDR than the 14bit HPSDR set ups.
Thanks, I’ll have to keep my eye on that one as well. :slight_smile:

Hello,

Have someone test the transmit performance?
I hope that we not have to make changes on these 2 output path’ s also.

Regards Ben

@N2EME,

Paul - Come back to the LimeSDR fray…We have HF working for the Lime…!! Hope to see you on the threads and active with Lime!

73 de Marty, KN0CK

Nils,

Since the LimeSDR is an R&D item (not sold as a final assembled consumer product or finished-goods item) then the LimeSDR is exempt of any CE Marking. I’ve run across this here in the U.S. and R&D items are not enforceable to CE Mark.

I’m not the ‘end-all’ authority on that, and I would ask Lime Microsystems to perform due diligence on this to confirm that, but they cannot remove your LimeSDR if you’re using it in an R&D capacity for the purpose of learning.

@andrewback Can you confirm or deny that since you’re in the EU (for a little while longer… :slight_smile: #Brexit)

Just my 39 cents on the matter - not final authority since I’m not the manufacturer…

73 de Marty, KN0CK

@martywittrock Hi Marty, Yes still following the threads as I do wish Lime luck in hope that they produce a 12GHz (10GHz Ham band) version using the 8xxxx.

I brought my children up with the saying P.R. beats P.O. Public Relations beats Pissed Off.

What annoyed me more than no HF ( to me 6m is DC) was the use of Alternative Facts.Isn’t that the way Americans have been dictated to refer to blatant lies these days? In the Ham Radio world M2 have patented the “That’s the first we have heard of that” line to such an extent that it has become a standing joke in the VHF world. Lime were attempting to muscle in on M2 copyright when saying that the 8th was the first they had heard of a, let’s call it a HF Problem. I know for a fact, as does anyone following threads on here or on other sites, that they were informed on the 23rd Jan but searched around for others to blame. That is why I personally contacted C.S. on my behalf. I am not adverse at all to grabbing my soildering iron and making changes. That and I figure most of these are going to come up on Ebay for 30c on the dollar from HF guys who do not want to get the irons out HiHi.

In my VHF Shack I use a Funcube Pro + as a benchmark on 6/2/222 etc… Has anyone had chance to compare the Lime SDR against a FCD+ yet?

I have not seen a refund from C.S. at this point. If one turns up then fine. If a Lime turns up instead then I am equally good with that. Either wa, 30c on the $1 or from my C.S. order I will be playing with a Lime.

Paul

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Hi, Marty - don’t want to ignite a discussion on paragraphs. But in all EU countries it is vital to follow the EU Directive for these kind of products, see http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32014L0053&from=EN
If you sell a “Radio Equipment” (in the sense of this directive, which LimeSDR undoubtly is) is must comply to some specifications, mainly in the field of electric compatibility. The producer certifies this compatibility with the CE label. Only CE certified products must be offered to the public. Hams (i.e. people with a valid amateur radio licence) are more or less exempted from this rule - see page 34 of the Directive). They may use LimeSDR without CE label. Another exemption are “custom built evaluation kits destined for professionals solely at research and development facilities for such purposes.” So, each customer in Europe who is not a ham cannot use such equipment at home without CE label.
Furthermore, any modification of the equipment by other customers than the above mentioned groups of hams & professional leaves the CE label invalid and use of this equipment illegal. This all may sound as, but are not remarks of a nitpicker. More of one who has some own experience in this field and heard from many others in Germany whose law suits ended not that happy as mine …
73 Nils, DK8OK

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Looks to me like, since you are a ham, you can modify whatever you want.
I saw nothing there forbidding you as well as an exemption for licensed hams.

Kinda annoyed I have to break out my soldering iron to fix low frequency reception, but on the other hand I don’t really care - The 700-900 and 2G+ bands for cellular, 915 ISM and 2.45 ISM cover what I’m interested in working with at the moment. I do wish there was a bit more feedback taken during the development phase last summer on what band usage people were interested in, as it doesn’t make sense, especially for the wideband input receiver, to not go below 700 MHz.

I think the real screw-up, though, is on page 4 of the schematics. Rev2 of the LimeSDR should break out the baseband analog I/O pins for usage up to 30MHz. These frequencies are so stupidly low that direct sampling with the built-in converters is possible, and there is zero need for an RF direct-conversion mixer front end here. I’d bet it actually probably hurts the overall noise figure.

Oh yeah, I’ve just did.
UPDATE: I’ve probably jumped the gun here, and I am wrong. Sorry everyone.

According to the datasheet, LMS7002M is not capable of transmitting lower than 30MHz AT ALL. I probably should have opened the datasheet before backing, but it definetely should not have been advertised as “Continuous frequency range: 100 kHz – 3.8 GHz”!

Radek, OK1SSH

Where do you see it can’t transmit lower than 30 MHz? It looks like the PLL Synth can’t tune or divide lower than 30-MHz in the datasheet, but it does clearly state it does support NCO mixing up or down the entire bandwidth range (which should drop it all the way down to 0).

Page 5: “Output Frequency Range” 30 - 3800MHz

Scroll up half a page. That section covers the RF Synthesizer specs. I don’t know how Lime designed their PLL/VCO section so I can’t comment on specifics, but that should just mean direct tuning lower than 30-MHz might not be possible. Page 3 covers the actual RF output specs and confirms this.

You don’t seem to have a background in EE but if you’re curious how it can get lower, check page 7. The digital processing circuitry inside the LMS7002M supports a lot of digital filtering, including a module that supports digital up-/down-conversion. So while the RF mixer can’t tune lower, the system can digitize centered at 30-MHz, +/- 30 MHz and then re-center the spectrum with the built-in mixer.

The parameter in datasheet is called “Output frequency range”, not “PLL lock range”. And of course I looked at the datasheet only after I’ve configured gnuradio to transmit at ~7MHz and after debugging not seen anything reasonable on the scope. It looks like the TX output drops significantly with lowering frequency below 30MHz.

It still might be a software bug but I doubt it.