In previous posts we showed how Phillip Hahn had been trying to use his RTL-SDR as a GPS receiver on a high powered rocket in order to overcome the COCOM limits which prevent commercial GPS devices from operating when moving faster than 1,900 kmph/1,200 mph and/or higher than 18,000 m/59,000 ft.
In order to test future flights with the RTL-SDR GPS receiver, Phillip has been simulating GPS rocket trajectory signals and using his LimeSDR. The RTL-SDR then receives the simulated GPS signals which are then fed into SoftGNSS for decoding. The simulation simulates the Japanese SS-520-4 rocket which is a 32′ long, 2′ diameter small high powered rocket capable of putting loads like cubesats into orbit affordably. Using the simulated data Phillip is able to calculate the trajectory and see all the motor burns in the velocity profile.
While Phillip intends to use the RTL-SDR on a similar rocket in the future, he notes that the simulation does not take into account problems such as thermal noise, or RF interference, rocket jerk, satellite occlusion and vibration problems.
LimeSDR Simulated GPS Rocket Trajectory Received with RTL-SDR.
The LimeSDR is a RX/TX capable SDR with a 100 kHz – 3.8 GHz frequency range, 12-bit ADC and 61.44 MHz bandwidth. Back in June 2016 they reached their $500,000 goal on the crowdfunding site crowdsupply. They are now gearing up to enter mass production the final product. Recently they released a production update which is quoted below.
Production Progress
Since the successful close of our funding campaign, We’ve been incredibly busy preparing to deliver LimeSDRs to all our backers. Just as we worked hard during the campaign – internally, with key partners, and with our fantastic beta testers in the community — creating a series of exciting demos, we continue to work to ensure backers will have a first-class experience upon receiving their hardware. In this update, we’ll review the state of the production schedule, hardware design, testing setup, documentation, app store, and more.
Production Schedule
To be upfront, our production schedule has slipped, but not by a lot. We discovered that some of the parts used in the original LimeSDR design have since entered end-of-life status, so we redesigned the board with replacement parts. In addition, we are still waiting on manufacturers for a few key components, such as the high-precision oscillators. We are in close contact with those manufacturers and our best guess right now is we will have all components by mid-November.
Once we have the components, our manufacturing partner in Taiwan can very quickly produce the entire lot of LimeSDRs. The assembled boards will then be sent to the UK for final quality assurance and packaging before heading off to Crowd Supply’s warehouse for delivery to all backers.
Given all this, we expect all LimeSDRs, including the Aluminum Kit version, to be delivered in December. Of course, we will update everyone as soon as have more information. In any case, we will post an update at least once a week between now and delivery.
Update Your Shipping Address
You will know your order has shipped when you receive a shipping confirmation email from Crowd Supply. The shipping confirmation email will contain a tracking number. If you need to change your shipping address, you can do so by logging into your Crowd Supply account. If you didn’t already have a Crowd Supply account, one was automatically created for you when you placed your order. We will post a separate update letting you know about the cutoff date for updating your shipping address.
Hardware and BoM
We have been contacting all the component suppliers and manufacturers and placing orders through our operation in Taiwan. As part of this work we wanted to make sure that no component will become end-of-life for at least 2 years. As a result, we have had to make minor changes to the board to replace some of the older parts. This was followed by another set of prototype runs to ensure that there is no impact on performance and manufacturability of the boards.
First batch of the Altera FPGA parts delivered to Lime headquarters yesterday.
Production Testing
A rigorous testing programme is essential with an advanced technology platform such as the LimeSDR and this work has just been completed. The LMS7002 production test had already been verified and running on industry standard Teradyne testers with RF test configuration. The program for the LimeSDR boards runs on x86-based workstations and provides an optimised test time while exercising all the functions, including frequency and bandwidth sweep across the full range.
Driver and Software Updates
We have already shipped over 100 boards to our community of beta testers for their feedback, before, during, and after the campaign. This enabled us to provide so many truly exciting updates during the campaign and, more significantly, we have been getting excellent feedback from the community, who have been simply outstanding in sharing their ideas for improving the user experience. We are making significant updates to the driver and calibration algorithms as a result, these are largely complete and will be pushed to Github before the end of November.
Documentation
We will continue to invest heavily in this area and see this as being key to demonstrating our steadfast commitment to the community. Giving you the best support begins with well structured documentation. Obviously, we rely here on your input and feedback. Making the process as smooth as possible is key, we have already started to publish data sheets and supporting documentation on the Myriad-RF Wiki, and will continue to do so as we gather your comments and suggestions.
LimeNET App Store
One of the key activities which we believe will set LimeSDR apart from other software-defined radio solutions is the concept of app-enabled SDR. With this, developers can provide their solution as a incredibly simple to install app, complete with all the various dependencies — with optional support and certification etc. — and publish it via the LimeNET app store. We envisage a rich ecosystem of many applications, resulting in a fantastic out-of-the-box user experience as the maturity and sophistication of the algorithms and software routines improves over time.
We are working very closely with Canonical (the organisation behind the immensely popular Ubuntu Linux distribution) to put in place the app store infrastructure and plan to have a basic service running and populated with a few initial apps by the time the first boards go out.
We are currently in the process of setting out the criteria for publishing an app in the LimeNET store, along with the associated terms and conditions. This is another area where we plan to seek input from you, our backers, to encourage the widest participation and cater for a variety of business and revenue models for developers. There will be numerous posts and updates on this topic, with plenty of opportunity for your input, comments, and feedback.
Last but not least, we shall be posting regular updates as we get closer to the deadline. This will be similar to during the campaign and with plenty of details, including things such as component delivery status, manufacturing progress, and delivery dates for the pledges made by you in all the different categories.
Thank you once again for your support and here’s to the exciting weeks ahead!
The LimeSDR is a RX/TX capable SDR with a 100 kHz – 3.8 GHz frequency range, 12-bit ADC and 61.44 MHz bandwidth. It costs $299 USD and we think it is going to be an excellent next generation upgrade to SDR’s with similar price and functionality like the HackRF and bladeRF. Back in August we posted how they had added HF functionality to their drivers, and posted some videos from LimeSDR beta tester Marty Wittrock who had gotten HF working well in GQRX.
Now that SDR-Console has added support for the LimeSDR and HF reception, Marty has uploaded two new videos showing it in action. The first video shows some SSB reception on 40M and the second shows some CW reception on 20M. Marty runs SDR-Console on a MSI Core i5 Cube PC. Marty also writes:
Even with the ‘older’ LimeSDRs that I have that don’t have the proposed modified matching networks on them the performance at 20m and 40m was actually REALLY good for voice and CW. Obviously if the band conditions for 15m and 10m were better the days that I tested the LimeSDR it would have been even better since ‘as-designed’ matching networks seem to do better at 30 MHz and up. Checking the performance at 162.475 MHz (my local Cedar Rapids, Iowa NOAA Weather Station) the performance is excellent on a VHF antenna.
The LimeSDR on 40m Phone using SDRConsole V3.0
LimeSDR Operating on the HF 20m Band with SDRConsole V3.0
Back in June the LimeSDR completed its $500,000 crowd funding goal. The units are still in production and have not yet shipped, but the software is currently being worked on heavily. In a recent update they have enabled HF reception on the LimeSDR hardware. LimeSDR beta tester Marty Wittrock wrote in to let us know his review of the new update:
Another major step forward for the LimeSDR yesterday…
As a part of the continuing development of the PPAs for Ubuntu and other distros, the LimeSDR is now supported for native HF tuning – – no transverter required. Receive has been functionally tested from 7.0 MHz to 56 MHz and even with the matching networks as they are in the LimeSDR I have (which is not what will be delivered in November – the LimeSDRs the backers will receive in November will have modified matching networks to be more broadband and perform better than what I have right now) the receive quality was very good with my applied HF station antenna (ground mounted vertical for 80m – 6m). I shot two videos yesterday of the LimeSDR operating on the 20m band – one with USB voice and one with CW/RTTY on the contest weekend for RTTY (REAL active). I ran this completely from a USB 3.0 Flash Drive plugged into a Dell 3020 and booted from that Flash Drive to operate the LimeSDR. The Flash Drive is loaded with Ubuntu Xenial (16.04), all the applied support files (SoapySDR, GNURadio, OsmoSDR. etc) and the application GQRX to tune and demodulate the LimeSDR. The setup worked VERY well and the results can be viewed with the two videos provided here:
20m Phone Using the LimeSDR in Native HF Tuning Mode Receive
20m CW and RTTY Using the LimeSDR in Native HF Tuning Mode Receive
Again, I was impressed with the quality of the direct, native, HF tuning of the recent updates to LimeSuite. Having this functionality in LimeSuite finalizes for receive, but I still need to check out the transmit. It’s my hope that Simon Brown’s SDR Console V3.0 will update with the new HF tuning improvements such that I can use his app on Windows to do a full checkout in receive/transmit with the LimeSDR and hopefully apply it to the WSPR app to have the LimeSDR operate HF digital modes on the HF band and Amateur Radio frequencies to have the first true LimeSDR operation benchmark.
I fully intend to have Flash Drive images available for download once I put the final touches on the Flash Drive I have. This will allow all Hams that want an instant solution for booting Ubuntu and running GQRX for receive to use their LimeSDRs right out of the chute without having to install ANYTHING provided that they have a PC that is decently fast (3.0 GHz, 8GB RAM) and has USB 3.0 ports on the PC. I’m looking for a reliable means to read/write the Flash Image and then take the image and ‘burn’ other USB 3.0 Flash Drives with the image. Once I have that reliably working, I’ll post the image and the Flash Drive app so ANYONE can make their own from a blank 32GB to 128GB Flash Drive.
More to follow on the HF transmit as I have those apps and check that out – – Stay tuned..!
The LimeSDR is a RX/TX capable SDR with a 100 kHz – 3.8 GHz frequency range, 12-bit ADC and 61.44 MHz bandwidth. It costs $299 USD.
rtl_fm / rx_fm: Allows you to decode and listen to FM/AM/SSB radio. rtl_sdr / rx_sdr: Allows you to record raw samples for future processing. rtl_power / rx_power: Allows you to do wideband scans over arbitrarily wide swaths of bandwidth by hopping over and recording signal power levels over multiple chunks of spectrum.
rx_tools is based on SoapySDR which is an SDR abstraction layer. If software is developed with SoapySDR, then the software can be more easily used with any SDR, assuming a Soapy plugin for that particular SDR is written. This stops the need for software to be re-written many times for different SDR’s as instead the plugin only needs to be written once.
rx_power scan with the HackRF at 5 GHz over 9 hours.
Over on YouTube LimeSDR beta tester Marty Wittrock has uploaded several videos showing the LimeSDR receiving HF frequencies. In the first video Marty shows it receiving the USB voice on the 20m band during the 2016 ARRL field day. The second video shows reception of PSK31 signals. More videos are available on his channel if you are interested.
In the videos he uses GQRX and his own KN0CK HF upconverter. The LimeSDR should be able to receive HF on its own without an upconverter, but at the moment the HF capabilities have not been programmed into the drivers yet, so during this beta testing period an upconverter is required.
Marty also wrote in to us to make some comments on his experiences with the LimeSDR. He believes that the LimeSDR is amazing and writes:
The quality of the receive and audio [of the LimeSDR] is incredible against other SDRs I have in the house (Flex 5000A, RTL-SDR, HackRF, Red Pitaya – and soon SDRPlay).
Marty also writes that he will soon have more videos of the LimeSDR operating in Windows with SDRConsole in the near future, and we will post those videos too when they are ready.
The LimeSDR crowdfunding campaign is now in it’s final few hours (22 hours left at the time of this post), and funding is up to 95% or 473k out of its 500k goal. After a few unsure days it looks like the goal will be reached just in time. The LimeSDR is a RX/TX capable SDR with a 100 kHz – 3.8 GHz frequency range, 12-bit ADC and 61.44 MHz bandwidth. We’re not affiliated with LimeSDR in any way, but we think it is shaping up to be a much better version of the RX/TX experimenter radios that are on the market now, such as the HackRF and bladeRF. For a price lower than the HackRF you get a much better ADC, a larger bandwidth and full duplex TX/RX capabilities. The LimeSDR capabilities appear to be close to the Ettus Research B210, which usually sells for over $1000 USD. Also, one of the drawbacks of radios like the HackRF and bladeRF was the lack of decent ready to go software apps. LimeSDR have made promises to focus hard on developing a software “app” store for the device meaning that application software will be able to be downloaded very easily, not to mention that all their software and hardware is fully open source.
During the crowdfunding campaign the LimeSDR is available for an early bird price of $249 USD. After the campaign the price will be raised to $289 USD for preorders, and $299 USD once the device actually begins shipping.
In a recent update they show the LimeSDR being used to receive GPS satellites and decode the data in GNU Octave and also mention that the app store development will begin once crowdfunding is successful.
The LimeSDR with four antennas attached.LimeSDR Goal Almost Reached.
The LimeSDR is a new transmit capable software defined radio with a 100 kHz – 3.8 GHz frequency range, 12-bit ADC and 61.44 MHz bandwidth which is currently seeking crowdfunding. At the time of this post there is about four days left to reach the $500k goal, and it is only 80% funded. To try and reach their funding goal they have released another batch of discounted units which cost only $249 USD. After the crowd funding campaign the price will rise to $289/$299 USD. If the LimeSDR is not funded in time, they write that the project will unfortunately be put on hold and it’s future may be uncertain. We believe that this product is shaping up to be a very good TX/RX capable SDR, like the HackRF and bladeRF, but much better overall and for the same or even lower price.
Recently they also released some new updates that show off some LimeSDR features. In a post previously featured on our blog beta tester Alexandru showed how he was able to get the LimeSDR to transmit DVB-S2 HDTV. In later updates they showed how the LimeSDR can be used to:
Control LoRa based IoT devices. In this post they used the LimeSDR to demonstrate how it can be used to transmit to, receive and simulate IoT devices running the popular LoRa wireless protocol
Create a 10 MHz LTE cellular site. In this post they also show a mobile phone connecting to the cell site and using LTE mobile internet at 20MSPS.
Create a Vector Network Analyzer. With the help of a directional coupler the LimeSDR can also be turned into a Vector Network Analyzer to measure parameters such as gain, insertion loss, return loss and VSWR.
Build a remote radio head. By mounting the LimeSDR near the antenna and streaming the data back over an IP link, coax feed losses can be eliminated.
