RASDR4 shielded Enclosure Kit for LimeSDR. Radio Astronomy focus via SARA

Announcing RASDR4 Enclosure Kit for LimeSDR

The RASDR4 team is pleased to announce details of RASDR4 shielded Enclosure Kit for the LimeSDR and readiness to accept orders. Pictures of the prototype and production components, kit parts, assembly instructions, and ordering information are available at www.rasdrllc.com . If you order a LimeSDR board from the vendor (www.crowdsupply.com), please select the USB Type A connector. Initial RASDR4 Enclosure Kits were announced Jan. 1 ago to SARA members and were sold as by Jan. 3, 2016 so we’ve ordered more components. Anyone may submit an order with the understanding that SARA orders have priority.

Enclosure Kit details:
– Designed for Radio Astronomy and tested with a v 1.2 LimeSDR board;
– All parts supplied with kit: no soldering, cutting, filing or special assembly required;
– Sturdy .06” / 1.5 mm custom stainless steel panels with laser cut openings and etched markings;
– Six SMA connectors with coaxial cable leads and u.FL connectors, covering (2) RX, (2) TX, (1) Optional IO, and (1) Reference Frequency Input;
– Extruded black anodized aluminum split shell case with post-anodization reamed screw holes;
– Passive cooling design resulting in air flow through RF and control panel ventilation holes, adequate for single-channel Receive Operations at typical ambient room temperature;
– Active cooling (using optional fan) to mitigate the effect of higher ambient temperatures or simultaneous operation of multiple TX/RX functions;
– GPIO port: D-SUB 15 position connector (provided) can be integrated with a forthcoming GPIO Kit;
– External visibility of all activity/status LED sets;
– Design attention to limit corrosion in selection of materials and contact points; and
– Design attention to shielding and ground loop prevention.

We suggest that all users monitor board temperature during operation. The team chose the above features to support our plans for radio astronomy measurements in a variety of environments.

A basic Enclosure Kit is available at a cost of $75 (postage included). This is non-profit and purchasers are expected to share findings with the community. Users must supply their own LimeSDR, antennas and preamps, USB Type A extension cable and an optional DC power cable/source. SMA connector cables from the front 6 ports to the board connection points are included – external antenna and LNA are not included. The D-sub connector is for planned expansion. We’ve tested several fans and will make our selection available as an option.

The team is working on a GPIO subkit that will include ESD and over-voltage protection. A challenge to testing is that the Altera FPGA firmware must be modified to test operation. We could use help with FPGA programming, general software development, documentation and testing. If you’d like to be a member of the team or help with our observing projects/documentation (H1 signals any time, August 21 experiments, etc.), contact David Fields (fieldsde@aol.com). For questions about orders, contact Paul Oxley (oxleys@att.net). To discuss our software and website, contact Paul or Tony Bigbee (tony.bigbee@gmail.com). For project management information, contact Wayne McCain (Wayne.McCain@athens.edu). To discuss interactions with the professional community and advanced projects, contact Stan Kurtz (skurtz@mailaps.org).

RASDR4 and all of its supporting hardware/software are considered an experimental, development-level kit product. No warranty is expressed or implied by RASDR, LLC, beyond covering shipping shortages or component defects. The LimeSDR board and components are not warranted by RASDR, LLC.

David Fields for the RASDR team