I’m from Czech rep. so the same european union as yours… Here you definitely cannot transmit on frequencies you don’t have license for (HAMs can transmit only on HAM frequencies) and for bands where it is generally allowed you must have CE approved device. So most end-users cannot legally transmit at all. Stuff like running your own GSM/3G/4G BTS/repeater are off limits even for HAMs.
But I’d seriously doubt someone will have issues with receiving signals with LimeSDR (or any other non-approved device). You probably can’t legally sell those devices but just don’t see how could someone be prosecuted for owning or using the device in non-disruptive non-interference way. I’m no lawyer, but I think the directive you’ve mentioned in previous comment cares about importing and manufacturing of the devices. Or is that stricter version “only” in some german law?
Oh, and by the way, I had to clear my LimeSDR through customs and they were only interested in VAT.
12db ? … Ha, yea thats what i get for doing math in my head … 1.2 or 12 factor of 10 …
which is why i usually just reference a chart …
Like this one …
http://ifmaxp1.ifm.uni-hamburg.de/DBM.shtml
from 30mhz to 25 is only .2vPP drop for 5Mhz (.4db/Mhz)
25Mhz to 20Mhz is 0.6vPP drop …
looking at the chart … i find a difference in vPP that’s about the same… i found 796.094 mVPP (2dbm) … then drop the voltage PP by aprox .6vPP – i used 199.970 mVPP(-10dbm) … that’s ~12db or so … so yea , 2.4db/Mhz there abouts.
Wonder why its squarish looking when output is rated at 10dbm …
Ill bet that the bias T chokes need to be larger value … a too small inductor affecting signal path?
I commented in another thread about using some conical chokes(bias T) to increase choking impedance in the HF region … maybe.
100uH@20Mhz should be 12.566K – that should be plenty id guess …
… to sort this out a bit, focusing just on the situation in Germany and on my experiences here:
- LimeSDR is a “radio equipment” and experimenter’s board, plug and play
- it doesn’t show it’s possibly CE conformity by a CE sign
As such, it can be legally: - imported and sold by companies, institutes and hams
- used by hams within the limits of their licence (i.e. trasnmitting only on the amateur radio bands) and other telecommunications law; plus professionals on their job, plus governmental agencies and the military
Importing, buying and of course using such a “radio equipment” is illegal and prosecuted with fines of usually in the range of 5.000 to 10.000 Euros. “Using” also covers “having the board at home, not being connected to power/antenna, but ready to be so in due time”. That’s not theory, but proven fact. It covers even listening, not just transmitting.
However, with CE sign, such “radio equipment” can be used by each and every person according to the law. That is: each and every ordinary person can receive within the limits of the law, each other can use it also on transmit according to their licence.
What means “receivng with the limits of the law”? Even that depends. If you listen to more than broadcast and ham radio, this might be illegal. But to comment in detail on these things, would stretch this “Discourse” too far.
My own experience with German customs is that they are only interested in VAT. (They don’t know that I am a ham.) I import such SDRs not as “radio equipment”, but as “modem”, which they also are, but sounding not that mysterious to them. So I was very much surprised to learn from the editors of an electronics magazine that numeous readers run into severe problems in importing such goods - maybe as hams or ordinary people.
Do you have any source for this (esp. prosecution for having the device at home)? I have a few friends that would find this interesting… (However we’re quite a bit offtopic here).
Thanks
There is a huge array of development boards and maker etc. platforms and I would have thought that in the vast majority of cases, certification would be meaningless, since a simple change would invalidate it.
With an intentional radiator, such as an SDR that can transmit, could you even achieve certification if it is not provided to support a very specific application(s) and has the associated Type Approval? Again, even if you could, the moment you run application code other than that which supplied, this would be invalidated.
We are looking at options and there should be an update within the next few days.
Thanks, Andrew - German (and European) law is as easy as strict:
- ordinary people must buy and use any equipment only with CE conformity, within the limits of telecommunications law. That means that these people then could use LimSDR as a receiver, not as a transmitter. Usage is solely in their responsibility. If they offend the laws (or law enforcement agencies think of that …), they will be hold responsible for this. This usually ends up in house search, confiscation of at least the board, prosecution and almost surely condemnation to a fine of rarely less than 5.000 Euros, but easily the double of that.
- ordinary people must neither buy nor use radio equipment without CE sign. If - see above.
- to sell (!) these equipment with or without CE sign is allowed. So German law enforcment agencies usually seize sales or customs documents do derive some information for prosecution from them. It’s their business model.
- there are exemptions from this for e.g. hams and professionals at work etc. if they obey to the limits of their licence and the telecommunications laws.
If someone is changing (modifying) an equipment bearing a CE sign, this sign is lost without discussion. This case can be easily followed if it is a hardware mod. But they may also check software mods which may e.g. increase output power or harmonics above a given level. This is the problem of the user. Thus, even a ham must not run a transmitter with an encrypted mode “on the air” - it must be “open”.
Sorry to bother you with all this stuff. But I think you should make this point quite clear to your customers. You may offer LimeSDR with of without CE sign, with or without modification. That’s your decision. But how you decide, has severe impacts to your audience.
(ISM and CB equipment has to follow special rules to get CE approval and to be used by ordinary people to transmit with on these bands. There is no special approval for ham radio euqipment, as they are “professional” in the sense of the law who should know what they do.)
In practice, many people just buy a large batch of CE signs, glue it onto their equipment - and are done without certification etc. So, law enforcement takes samples of many different equipment and checks if it comply to the certification. You may imagine the results.
Thanks, BTW, for looking after any options: Nils
… just take me … I was target of denunciations by fellow hams, experienced two house searches, confiscation of equipment etc. I won the law suit that followed, first class. But this is rather unusual because defendants are offered what we call a court settlement: without the questionable result of a lengthy and costly trial you leave the court a a free man - if you pay around 6.000 Euros. Nearly all cases end up this way. This is done behind closed doors. Thus, I know of these cases only by confidential information of some lawyers (as my case made some waves), and cannot disclose names etc.
For us in the EU it would be easier if the board would be delivered directly from Lime Microsystems
Hi @SabineT I’m afraid this is not possible, as all fulfilment is handled by Crowd Supply in the US.
Thanks for the update Andrew.
Do I need to do anything with CrowdSupply and halt the order until a decision is made?
Dear Andrews,
My previous question, is currently unanswered by you!
Where are you located, geographically?
My German and European friend, Nils, is not wrong, regarding the legal aspect, which can really frighten, normally to all!
In France, it is said: No one is supposed to ignore the Law!
But what? Legal: but what Country? Financial: but what Country?
I prefer to hide this point, however important.
On the Customs side it is only possible to recover VAT.
It should also be noted that this product does not do any good to the Planet!
It is also a very big problem for all of us, but I also want to go beyond this crucial point.
LimeSDR is already manufactured, has made thousands of miles or miles in different directions and I think it is currently blocked for modification and we do not know where!
Friend, Andrews, QUESTION:
When, do you think your organization, World Company, will ship our product, bought for a long time, in 100 KHz compliance?
It will inevitably have to be conform in HF 100 KHz up to 3.8 GHz, but also of course, in reception “RX” when emission “TX”.
See you very soon
Bernard
It not a bug, it’s a feature.
Because my LimeSDR is still stuck somewhere between customs and my home, I have had time to think a little bit about the optimal filter settings and the impact of the reduced sensitivity for low input frequencies.
At first I thought the reduced sensitivity for lower frequencies was pretty lousy (sorry Lime). But after thinking it over maybe it is not so bad after all.
In the Table below I have listed some values about the optimal LP filter to be used, the sensitivity of the LimeSDR and the level of manmade noise.
Columns1-5 show the lowest HF band -input frequency you want to receive, the corresponding frequency after mixing with 30 MHz LO, the optimal low pass filter to be used before the ADC, and the input frequency range that is not attenuated by the low-pass filter.
Due to the Lime architecture for decreasing input frequencies the cut off frequency of the low-pass filter before the ADC has to increase, resulting in a wider input frequency range that passes the low-pass filter after mixing and arrives at ADC input. So especially if you are only interested in the low HF frequencies it would be good to use a low-pass filter before the LimeSDR.
Column6 shows the digital RX level for a signal of -45 dBm, from figure1 – Easyfix1 of the 10.2.2017 document by Danny Webster. Column 7 shows the estimated Noise Figure. I have assumed that, if for a frequency band the sensitivity of the LimeSDR is n dB lower then at 30Mhz, the noise figure at this frequency band is n dB higher then at 30 MHz (10 dBm).
Column 8 shows the typical noise level in a 500-Hz bandwidth for a rural environment according to Rec. ITU-R P.372.7, Radio Noise
Table 1
Going from 10m to 160m the estimated noise figure increases by 40 dB from 10 dB to 50 dB but this is almost compensated by the manmade noise that increases by 36 dB from -118 dBm to -82 dBm.
So if you have a wideband antenna available with a flat response over frequency (e.g. a wideband RX magnetic loop ) then the reduced sensitivity for lower frequencies is no disadvantage. It might even save you an extra filter to reduce the level of strong LF – MF signals.
Cornelis , DG7SEH
@Bernard, I am based in the UK.
As stated previously: LimeSDR, as an eminently hackable device, is not CE certified. And once again, we are looking at options with regards the possibility of supplying boards matched for HF use.
Cornelis - your table is a good point, thanks.
It is part of the answer to the most vital question: What can I expect in practice? There you have to find the optimum between sensitivity and distortion. On HF, one reckons with undistorted reception at dynamic ranges from 100 to 120 dB / depending on the antenna and preselecting filters. So, we will have to place LimeSDR’s HF dynamic range of about 75 dB at an optimal position depending on “conditions”. This can be made even with 8 Bit SDRs like HackRF with great success and worldwide HF reception - if you know, what you are doing. Sometime a bit of noise(factor) offers a bright outlook … 73 Nils, DK8OK
What about the performance difference between 1.2 and 1.4 boards. Lime said that they have the same matching networks. So, maybe there is a drivers problem?
I’ve yet to see hard evidence of this and thus far only seen anecdote. In our testing we found the performance to be the same and this would have been using the latest drivers available. If someone can give me a concrete example of a performance difference you can be sure we will investigate this thoroughly.
Andrew
I received the message from Crowd Supply indicating that the removal of one inductor would solve the problem, Has anyone run a gain frequency or return loss run on the -W ports?
Up until the Git-Hub updates destroyed the firmware on my V1.2 board, I was able to use the -W ports at 21 MHz. I cant repeat the tests since the board no longer can setup the test.
Paul
In the ‘early go’ there appeared to be a difference in performance between the LimeSDR V1.2 and V1.4. But since the ‘EasyFix’ was applied to both boards, I am now here to say that there are imperceptible differences between both boards…No kidding - they’re playing the same now.
Hope this info helps,
73 de Marty, KN0CK
@martywittrock thanks for the answer. Has the v1.2 board with coil the same performance as the v1.4 board without the coil?
I’ll ask the question.
What do you mean by "destroyed the firmware? You should always be able to re-flash and at worst case this would simply mean removing the boot jumper for the FX3 and using the Cypress utility.