Ex-commercial Marconi and naval radio equipment

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Anyone interested in acquiring ex-commercial Marconi and Naval radio equipment can do so by making a suitable donation to a merchant navy charity, RNLI, or Radio Officers Association.

The equipment is stored in southern England, with 1st September 2014 given as the final day for storage.

Further details and information is available from George Clive Evans on email, georgecliveevans@yahoo.co.uk.

Etherkit releases CRX1 - A new 40 meter receiver kit

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Etherkit have  announced the release of their newest product, the CRX1 receiver.

The CRX1 is a simple VXO-tuned superheterodyne receiver for the 40 meter band, with tuning centered around the popular QRP watering hole frequency of 7.030 MHz.

It is entirely constructed from surface mount devices in the easy-to-build 0805 (US) size for passive components and SOT-23 class semiconductors. The PCB is large and single-sided, which provides for uncramped construction and makes the CRX1 an ideal warm-up kit for the CC1 QRP transceiver (coming soon).

The CRX1 is not just meant to be a novelty to be tossed aside after construction. All of the support circuitry for muting, T/R, and sidetone is included, so it can be paired with virtually any transmitter which uses grounded keying. There is also a port for an external VFO to enable further user experimentation. All controls and connectors are included with this kit, so you just need to supply an enclosure and a few knobs to finish the job!

Specifications

  • Frequency Range: Approximately 7.030 to 7.034 MHz (at +13.7 VDC power supply)
  • IF Bandwidth: Approximately 400 Hz
  • Current Consumption: 25 mA (at +13.7 VDC power supply)
  • Power supply: +9 VDC to +14 VDC
  • MDS: -123 dBm
  • 3rd Order IMD DR: 84 dB
  • IF Rejection: 74 dB
  • Image Rejection: 67 dB
  • PCB dimensions: 70 mm x 100 mm
  • Antenna Connector: BNC
  • DC Power Connector: 2.1 mm barrel jack
  • Phone Jack: 3.5 mm stereo
  • Key Jack: 3.5 mm stereo
  • Reverse polarity protection
  • Muting, sidetone (user enabled), T/R switch, external VFO port included
  • Available Bands
  • 40 Meters – 7.030 to 7.034 MHz
  • You can find it for sale here at the Etherkit store, along with all of the Open Source documentation and design files:
More information - http://www.etherkit.com/receivers/crx1.html

Inflatable antenna could give CubeSats greater reach

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MIT report researchers led by Alessandra Babuscia have developed a new design of antenna for small satellites known as CubeSats

Due the their small size CubeSats have been restricted to small monopole or dipole antennas.

Such low gain omni-directional antennas have restricted CubeSats to Low Earth Orbits (LEO) using lower data rates than would be possible with a large dish antenna.

The MIT team, led by Alessandra Babuscia, is part of the research group of radio amateur Professor Sara Seager KB1WTW and also includes graduate students Mary Knapp KB1WUA, Benjamin Corbin, and Mark Van de Loo from MIT, and Rebecca Jensen-Clem from the California Institute of Technology.

The new inflatable antenna developed by Alessandra Babuscia and her team may significantly increase the communication range of these small satellites, enabling them to travel much farther in the solar system: The team has built and tested an inflatable antenna that can fold into a compact space and inflate when in orbit.

It is claimed the distance that can be covered by a satellite with an inflatable antenna is seven times farther than that of existing CubeSat communications.

“With this antenna you could transmit from the moon, and even farther than that,” says Alessandra Babuscia, who led the research as a postdoc at MIT. “This antenna is one of the cheapest and most economical solutions to the problem of communications.”

Read the full story - http://amsat-uk.org/2013/09/07/inflatable-antenna-could-give-cubesats-greater-reach/