You, Myriad RF, major RF specialists, I allow you to make a request for assistance for me and surely many other people from the LimeSDR community
Allow us to operate the LimeSDR in HF reception in good conditions instead of letting the SDR languish at the bottom of a closet.
This would also be a very commercial and beneficial way for you not to let us down
Objective: Allow to receive in very good conditions the spectrum HF from 100 KHz
This only starts from the two entry points which are RX1_L, the points rfgp_1_RFE_1 (AN11) and rfgn_1_RFE_1 (AM12) of the LMS7002M RF1
By disregarding what you have currently set up on the map and possible modifications that you have communicated to us and which do not give satisfactory results
What would be for you Myriad RF, the best chain of components to obtain the best reception range of 100 KHz to about 30 MHz minimum or more if possible without degradation of the signals for this wide range HF.
This chain of complementary components HF to be set up on a separate card realized either by users like me or a realization by you in the form of a complementary kit realized and marketed by you.
Bernard, did you understand what it was you are buying here?
It is NO way a commercial product, it is a demonstrator board.
It was made so engineers could play with it and then design their own gear based on the LM7002.
What Lime has accomplished is quite amazing and I look forward to the HF specific bit of kit you design based on it.
In the meantime this particular board was tailored to the LTE/GSM/WiFi/IoT crowd and we lowly HF users weren’t really the target market even though we have enthusiastically adopted it.
This means it is up to the HF oriented community to fix our boards so they work reasonably for us, not Myriad.
They however have done an admirable job catering to the seemingly endless stream of HF people and Hams here who bought it without understanding the original target market. Good on them.
Now it is up to us to take it to the next level, not them. It is only up to them to make sure that our boards work at this point.
I’ve been using one of those with my HPSDR kit, works great. I highly recommend it or similar.
Don’t forget to pick up some bands pass filters for rx and low pass for tx, someone pointed out the wicked harmonics at HF and the rx will benefit greatly with some selective spectrum narrowing.
LimeSDR is completely different.
Sensitivity dramatically drops below 30 MHz, reaching -80dB at 100 kHz. There is no way to compensate for it.
This has been discussed before.
Sensitivity at 144 MHz is 5dB below the standard, e.g. rtl-sdr dongles, Airspy (having an identical rf part!), SDRplay.
Dear M0GLO
I am not an unconscious and I know what I have ordered.
I wonder though if you, you know well read and read the comparison table and different literature of technical specifications!
I ordered a new impressive SDR system with coverage from 100 KHz to 3.8 GHz
Very cordially
I am sorry Bernard, not to be in your face or anything but I read those same specs and and comparisons and they never said that it would be a stellar performer on HF.
They said it would tune, and it does.
In fact the actual datasheet for the LM7002 part itself only has spec’s listed to min 850Mhz, no other specs were given so I am wondering how you got the idea that this was supposed to be a screamer of a performer in the HF or even VHF.
You believed what you wanted to from what you read and ignored the actual content and what it was saying.
If you had paid attention to the marketing and datasheets you would know we aren’t the market and that it wouldn’t be tailored for us specifically. It is tailored for the crowd I originally listed, that apparently isn’t you.
That you are arguing the point goes to show that you misunderstood what you were getting into.
You ordered a beta development board from Crowd Source, not a commercial product.
If you want stellar HF then you need to do the footwork yourself just like the rest of the developer community that is looking to use this as a prototyping platform.
Just like the rest of us.
And a word of advice: if you aren’t willing to be an alpha or beta tester on product that is in it’s first release, particularly if you aren’t up to the task of making it do what you want without demanding the company do it for you then perhaps Crowd Source isn’t the place for you to shop.
This isn’t commercial gear, it is dev gear and it wasn’t designed with Hams in mind.
Of course, it was designed for UHF/SHF prototyping and development.
That is what the front end was spec’d for as per their sale lit.
It is up to US to rework our own boards matching networks and do the necessary software corrections to get it up to OUR spec.
They have delivered what was promised, that so many have read so much more into it is not Lime’s problem.
Step up, be a ham not an appliance operator for Gods sake!
I don’t necessarily agree with everything M0GLO has written here, but one thing is for sure … IT IS WHAT IT IS!
No point crying and screaming about in now. The reason I’ll keep mine is because … while it’s a bit of an underperformer on HF/VHF, it’s great for so many other things (experimenting with WiFi, BLE, LTE etc and all those new SHF bands opening up for hams).
As @JMG wrote above, Lime is almost completely deaf by the time you get down to 30mHz (which for this device is just about DC anyway). So it seems to me the best workaround is to bring HF up to where the Lime is more comfortable, like above 100mHz where JMG measured falloff to be only around 5dBm compared to other devices.
There are loads of super-bright hams in this forum doing exciting things in this space. I discovered this upconverter by Marty @martywittrock. It puts the HF bands into 120mHz for the Lime. Loads of videos on YouTube where he’s got it working very nicely on HF. I’m working with him to get one. Will report back here soon.
And of course, there is LNA4HF mentioned above that you can try. It’s not an upconverter, so 30mHz is still 30mHz to the Lime but at least you get ~20dBm gain boost, and a decent LPF for HF frequencies.
C’mon guys, let’s try together to make this the huge success it has the potential of being, and support our own fellow hams in the process :). I’m certainly excited about all the experimentation that lies ahead.
At first I must say I have one LimeSDR and I have fun with it because I am not using it at HF.
But I am total not agree with M0GLO, In the LimeSDR website , Myriad says it’s frequency rage from 100KHz-3.8GHz . That is not correct and look like to betray user.
You can not say this is crowd project and you can say any thing that project can not do .
I think Myriad need to correct it on website.
And it IS 100kHz to 3GHz, it never said it was a great performer at the lower frequencies and as I have repeatedly pointed out the development board we are buying was designed for guys to use at 800MHz and above.
Anyone who didn’t catch on to that wasn’t paying attention or is inexperienced re-purposing gear.
If ANY of you can show me where they gave performance specs lower than 100MHz in their sales lit and presentations please do, because it doesn’t matter if you disagree with me the fact remains that they have met EVERY spec they claimed in the various docs and releases. It really is that simple.
That’s not my opinion on it, it is the facts based on content in the same items that all of you read.
Anyone who thought otherwise didn’t understand, and anyone who still thinks otherwise still doesn’t understand.
It is getting a lot of great attention and the hams here are quickly kicking it into shape, but it was in actual fact NOT a HF marketed device and that was made obvious from the start. Just because the words Ham Radio were in the list never meant HF specifically.
So lets quit harassing Lime and Myriad with the they should do this for us noise and get on with being hams and making this ours like so many others on the forum are in the process of doing.
Now I’ve said my piece on this and won’t belabour it any longer, it’s here and presents the facts already.
Anyone with any modifying documentation from Lime or Myriad is welcome to present it and I would be glad to see where it does say HF was a performance area that was promised. I am sure we all would.
I do not harass Myriad , I only request they correct the information.
If they do not , they will lost their credit with HAMs community.
I am person which help them fix it at 10MHz range.
I also tell you I am happy with LimeSDR, but Myriad need say the truth.
And @sdr_research, let me say again THANK-YOU for being the one who worked out that removing the coils would improve <100mHz performance. That is some really fine work.
So you see? You’re already embracing the spirit of ‘make it work’. You’ve done us all a big favor.
But I agree … I for one would sure like to see changes to the ‘specs’ posted on Crowd Supply.
Didn’t say you did.
Requesting info is great, and not what this is about.
This is about telling Myriad they need to fix the boards to make them more Ham friendly, which they should not get involved with because any Ham who got the idea that theses were going to be great in the HF didn’t read the LM7002 datasheet and projected their wants onto the sales lits single use of the word Ham in the potential applications.
That and those same people seem to think it is a production board, which it most certainly is not. That misunderstanding is a major driver it seems for the Myriad must fix this for us posts.
They DO need to provide working boards.
They DO need to provide API docs.
They DO need to provide the datasheets.
And that is pretty much all they are required to do given what the board is and how and to who it was marketed to.
Enjoy the boards and do something great with them, what you do with them is your business and up to you entirely.
That is the point of releasing development boards.
Please read https://www.crowdsupply.com/lime-micro/limesdr at Comparisons , they have compare frequency range with another vendor. They should know they product cannot operate at 100KHz as they quote but they still quote and make compare . This is not nice!!
No dB info there, like I said you read way too much into it.
And it DOES tune to 100kHz, it just doesn’t perform there with it’s current hardware config.
And it was never stated that it did perform there. It states it TUNES there.
Seriously guys, the more you argue it the more it appears that even your claims of knowing what you bought aren’t up to snuff.
Guess I will just wait where this goes. Though I signed into the crowd campaign because I thought I would get a great broadband platform I am not really disappointed. The limeSDR is a great piece of technology and a step into the future of amateur radio, while at the same time let’s us all peek at the current state of the art of wireless communications.
It also comes with loads of software that will let those in the know (I am not one of these) create incredible stuff. The limeSDR will enable me to experience that first hand. This is not what I initially wanted, but then I got two radios that keep me covered when it comes to more traditional stuff.
So, it is a terrific tool to learn something new and to play with.
One thing Lime might have done a better job at is managing expectations. It was pretty clear at a very early stage of the campaign that loads of people where looking for a unit with good hf/vhf performance. Lime should have stepped right in at that time to put things straight. But it was also clear from the outset that this would be a development kit for mobile communications professionals, so everybody was sort of warned.
I am looking forward for a great experience though, whatever it will be.
As I said earlier, I don’t completely agree that LimeMicro made it abundantly clear this rig was only for the super-cool RF engineers, telcos, etc.
I went back to see what exactly attracted me to to LimeSDR in the first place. I think this ONE statement … together with the comparisons at the bottom of the page against HackRF, etc … made up my mind.
A SDR FOR EVERYONE … including us lowly hams? I hoped so.
Still, I’ve be around around long enough not to get caught by the clever words of some marketing specialist. In this case, my eyes were glazed over by the promise …
Either way, I’m dead-set on keeping mine. I have outlined a possible ‘work around’ to the HF/VHF ham bands deafness above (upconverter). Mine arrives Fri/Sat. Will let you all know. Either way, I STILL maintain we’ve got to give this thing a chance. It may not be perfect out-of-the-box, but ask yourself … what other TRANSCEIVER option do I have that might do HF to GHF on one board for ~$300?
So I finally got mine working with GQRX after fiddling around with sample rate and bandwidth settings. I am in fact using it with an upconverter based on the reports of the poor HF performance. While the upconverter at least makes it usable, the floor is about -80db unfortunately. Although I am picking up signals in the HF range, the RX performance still leaves a lot to be desired. Perhaps, I too, will still need to perform the modification of removing the inductor to get better performance at 125mhz + HF Freq
Perhaps i will need to throw a LNA in front of it as well.
