Where did the 100 KHz go?

It is well specified and several times in your argument that the LimeSDR is intended for a hole less range from 100 KHz to 3.8 GHz

There are 6 reception inputs
currently the receipt entries are:
RX1 L = 700 MHz - 900 MHz
RX1 H = 2 GHz – 2,6 GHz
RX1 W = 700 MHz – 2.6 GHz
RX2 L = 700 MHz - 900 MHz
RX2 H = 2 GHz – 2,6 GHz
RX2 W = 700 MHz – 2,6 GHz

Why not have planned RX1 L and RX2 L with beginnings of HF ranges of which one at 100 KHz?

The input transformers RX1 L and R2X L are currently planned with transformers Mini-circuits TC1-1-13MA +, 50Ω, Range 4.5 MHz to 3000 MHz

Why not have planned:
For RX1 L, a Mini-circuit transformer ADT8-1T 50 Ω Range 0.1 to 130 MHz
For RX2 L, a Mini-circuits transformer TC4-13TX + 50Ω Range 100 to 1000 MHz
Of course, each line composed of capacitors and inductances must be recalculated to optimize these reception inputs

Why did you not meet your commitments, for the range 100 KHz at 3.8 GHz?

Do you have a solution?

A French Baker currently very unhappy

Friendly thoughts to Marty and Simon

Bernard MALET



Can you answer Bernard’s question? Seems reasonable given that the CrowdSupply specs for the LimeSDR indicate as such. Please keep us advised.



Eagerly waiting a reply also, one unhappy ham…

Mine’s now packed up in the cupboard for the foreseeable future.

Shame :frowning:

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what a shame, what a promising SDR

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How do we get a refund, seems the Lime Guys have gone awfully quiet in here…

@martywittrock @Bernard the frequencies stated against the ports on the schematics are indicative of where the optimum performance is for those matching networks. However, the LimeSDR operates across the full frequency range stated, albeit not at optimal performance across the entire range.

Plots of the sensitivity and noise figure vs. frequency are being generated and we will share those soon.

@andrewback so 700Mhz is what I’ve seen as the lowest matching network??? So anything below that is pretty useless with degraded performance or am I wrong…

This is not correct. The frequencies noted indicate where optimal performance lies, but this does not mean that performance outside of which is going to be terrible. The plots should make things clearer.

@andrewback in the real world on an antenna, not on a signal generator the performance is awful…

@andrewback when @martywittrock was showing samples of his 1.2 on HF it looked great, then for the 1.4 you added the matching networks I believe, and marty told you all this before the launch…but you ignored his advice and added the 700mhz limit, this make the device nothing more than a geeks cell hacking tool…

As far as I am aware — and I need to double check — if we are seeing any differences between v1.2 and v1.4 it is probably configuration related.

After seeing Marty’s shots and talking to him, that’s why I jumped in early which I don’t normally do, but it looked good, and now the 1.4 is nothing like the 1.2 performance wise, I would suggest you stop production on any more and FIX this issue first, or Lime won’t survive long…or advertise it as 700Mhz - 3,8ghz…

I strongly agree with the comments that 100kHZ support, as delivered, must be supported in order to live up to the advertisements. Or at very least you should supply the filter options when ordering, failing that supply parts that can be replaced to make it work as described. Can you please give us plots of the new frequency vs sensitivity curves ?

I signed into the crowfunding campaign because the radio was advertised as being usable from 100 khz on. I am intersted in the range up to 300 MHz where performance is as bad as it gets. I feel being misled and ripped off badly And I expect a fix for this.

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I would like the performance of limesdr between 100 MHZ and 400 MHZ…
I want to develop a ground penetrating radar for my master project with the limesdr and
with all the previous comments. I’m not sure the performance of the limesdr will be enough to do my project.

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This is where custom filters/matching will be used best …
I do plan on replacing at least one pair of transformers … with an experimental microwave I/Q waveguide transformer …

and plots to 12ghz would be wonderful @ the point before the transformers are used …

Hah - I was OK with valve bases, kind of OK with TTL (made an iambic keyer), but this stuff is just way too tiny :slight_smile: .

I invested in the LimeSDR for cell band work, but for HF there’s always sdr.hu :slight_smile:

@cswiger I got mine for amateur radio as I guess quite a few others did, looking to build a qrp all band setup, the websdr’s are good, but nothing like having your own, at your own station, on your own antennas…it was advertised as 100khz and up…