Where did the 100 KHz go?

Wow, what part of developers kit and all the talk about WiFi/LTE/GMRS did you not get when you decided to buy?
That it does ham bands is a bonus, particularly at this perf and price point.
Mostly though these are DEVELOPMENT boards, not commercial radio offerings and if you are not getting the perf you led yourself to expect on a beta release crowd funded dev board then perhaps you need to start developing or hardware hacking to fix it.
I knew what I was getting into and I am still happier than ever with what is coming. If there is an issue I knew I would have to pretty much work it out myself because I bought a DEVELOPMENT board instead of an Anan or Hermes.
Seeing a theme here? The word starts with D.

This doesn’t mean don’t ask, don’t suggest and don’t create and share, what it means is don’t moan and complain that you didn’t get a Anan or Hermes when you knew you were buying a first run crowd funded DEVELOPMENT board.

73

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I didn’t receive my board yet but as some here and I already feel very disappointed.

However, @andrewback says it may be a configuration issue. I wonder if you could post the current attenuation for HF since 100KHz looks very far from 700MHz to me. Actually, why having any matching network in the board? Let me use any external ones I wanted to fulfill my needs.

Additionally, if those numbers will make LimeSDR less efficient than a SDRPlay RSP2 board for HF, I will feel very disappointed and for sure will try to sell my LimeSDR without even opening its box.

I check schematics , the input circuit is designed for > 700MHz only , so If you need low frequency you must modify input circuit. The spec. of LM7002M is 100KHz-3.8GHz but I do know why Lime design team designed input circuit very bad. So the Lime team was wrong when say LimeSDR frequency range from 100KHz-3.8GHz. This is the specification of LM7002M not LimeSDR because with LimeSDR it should be include input circuit. To solve the problem you need redesign the input circuit

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If you want to use at HF or another frequency range you need to mod RX_W input : remove 10nH coil , replace input transformer with a wideband one .If you using original transformer , it good with lowest frequency about 20MHz

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I would think that a WBC2-1TL could work well … if it is the same size as what is used in RX_W (TC1-1-13MA – 4.5Mhz to 3GhzHz) …

I use a WBC2-1TL (200Khz - 500Mhz) in a UHFSDR and 1.79Mhz Rx is no problem …

They are not quite the same size … but i bet it would fit …

You can remove 10nH coil at RC_W input and using original transform

I’m glad I’m seeing this conversation now rather than when I drop nearly €400. Getting a refund from a crowd-sourced project is pretty much impossible.

Dear Andrews
Your article from the 18th February, 2014

LMS7002M announced and new module in the works
By Andrew Back
18th February, 2014

Last week Lime Microsystems launched their second generation field-programmable RF (FPRF) device, the LMS7002M. This improves on the tried and tested LMS6002D by providing a dual-transceiver which is 2×2 MIMO capable, with frequency coverage extended all the way down to 50MHz, and that is based on a 65nm CMOS process which gives reduced power consumption.

Just a few of the key features of the LMS7002M include:
• Continuous coverage from 0.05-3.8GHz
• Programmable RF modulation bandwidths of 0.1-108MHz
• Transceiver Signal Processor (TSP) integrated between digital converters and IQ interface
• 550mW typical power consumption in full 2×2 MIMO mode

For further details see the product page, which includes a link to a comprehensive datasheet.
As with the LMS6002D, Lime will be making detailed documentation for system designers available without the need for an NDA, such as a programming and calibration guide.

Are you, the creator and the builder
You specify above: “Continuous coverage from 0.05-3.8 GHz”
My LimeSDR is not delivered so you can easily make the appropriate changes to the product

I have never ordered a LImeSDR for optimum reception at 700 MHz!
But i placed order for a LimeSDR coverage of 100 KHz to 3.8GHz

I expect from you a fast solution so that the LimeSDR can operate in reception and in good conditions in the part of the spectrum HF from 100 KHz and that on two inputs of reception

Bernard MALET

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Hi @Bernard, an update is in progress and repeatedly posting the same and similar remarks at different places across the forums is not helpful. Thank you in advance for your patience :slight_smile:

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Just a reminder of what Lime Micro promised in terms of broadband gain and NF performance on the 1.4 boards

They need to confirm whether they are meeting this offer spec.

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Yes, just cancelled my pre-purchase with crowdsupply. Money was refunded!

It is planned for when the diagnosis and the modifications to make, to obtain the 100 KHz?

I’d like to get a feedback on this as soon as possible as well. I suppose this information will help me decide whether to keep or cancel this order.

Considering their fulfilment centre is in the US we’ll all be better off if we cancel instead of returning it.

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The main reason to cancel rather than return is that from what I can see, crowdfunding is not the same as buying. The same ‘fit for purpose’ and sales description legislation doesn’t apply, as you didn’t buy something, you invested in a company and got a reward for your investment.
This is just my interpretation, but I have seen a number of cases that support this.

From a very Helpful Crowd Source Email that I received yesterday, 8th Feb. It explains that Lime are looking into the subject and also some options. Thank you to both Crowd Source and Lime for the information.
I was in touch with the team earlier today about this very issue and
they are looking into the reported change in frequency range. Their
initial guess that the report is incorrect due to some sort of set up
error and they intend to update all backers with their findings soon.
They only found out about this report yesterday and are working
quickly to get to the bottom of it. Your order is likely to be shipped
in by the end of next week, if not this week. If you’d like, we can
hold your order until the LimeSDR team posts their update. Of course,
it’s not a problem to cancel your order now as well. Please advise.

Quick Question … and this is just in theory …

the Lo lowest settable freq is 50Mhz ?
The ADC bandwidth is 56Mhz or so …

Then in theory, the LimSdr could Rx audio down to DC if there was no DC decoupling …

I wonder what is “Extended by TSP NCOs” exactly …

A quick update:

Lime engineers have done tests to compare v1.2 and v1.4 hardware — using @SimonG4ELI’s software — and found no difference in performance. If anyone has both those hardware revisions and is seeing a difference, all we can assume is that there is a configuration error.

Performance with v1.4 boards should be the same as demonstrated with v1.2 boards during the campaign.

A more detailed update, with measured performance and recommendations for optimising the performance below 100MHz, is forthcoming.

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Andrew,

What configuration settings are we capable of modifying beyond what SDRConsole allows us? I have PIA, TIA, and LNA gain settings at max and have also tried different combinations that are max’ed out to achieve similar results to my V1.2 board - to no avail. Are there other gain settings ‘under the hood’ that we should know about now so we can correct these errors?

Please advise at your soonest with that info - I’d like to see a baseline with my V1.2 board if there is a way of adjusting it either in the open or ‘under the hood’ so I can report this, too.

73s de Marty, KN0CK

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Screenshots of the software would help I think.

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@andrewback is this valid for all receiving ports? Or is this only for RX1/2_L and RX1/2_W?

So I guess now the proper question is if someone has confirmed (can confirm) good performance at low frequency with LimeSDr 1.2 and Simon’s application?

Also @andrewback as you seems to have properly working LimeSDR 1.4 + Simon’s Console app I think it can be used as a reference if you don’t mind providing some data to a community?
Can you please describe your exact RF test setup?

Thanks
Dimitar

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