Amateur radio projects from 73kHz to 447THz

SSETI Express: Launched 27/10/05 - shut down on orbit 9 with power system problem

          I'm Rachel, read about how you can help Wimbledon Greyhound Welfare            

Special feature: Not amateur radio, but a charity that finds homes for retired greyhounds. Click the picture of Rachel to read a little more about these affectionate animals and the work of Wimbledon Greyhound Welfare.

Crossing the Atlantic the hard way     England to Canada on 136k    4300km crossband 
A linear amp for LF
     Quarter kilowatt linear amplifier for L.F. 
More LF transmitters       A 100W  LF Class D Amplifier  from 13.8V
Match that antenna in seconds       LF - HF  Reflection Coefficient Bridge
As shown on the RSGB LF source book        300 Watts on 136kHz. A class D TX. (Jan/Feb 2003 Rad Com)
Oscar 40        AMSAT  Oscar 40.  Worldwide satellite communication
Build a dish feed the easy way        Helix dish feed kit for 2.4GHz
Gemini        Gemini :  S Band to 10m converter with 0.6dB NF
No long antennas at 670nm !       Laser transmitters / Receivers - 6 pages updated *NEW*
Kit and component pricelist
     Kits and components Index.

LF FET preamp        LF PreAmp and BPF. Make your  Japanese black box work on LF.
LF in practice     LF  On-the-Air   Antennas,   Photo's,  Coil's etc
Winter by the Irish Sea       L.F. Dx-pedition to the Isle of Man.
VSWR       VSWR Bridge for LF    Forward and reverse power at a glance
direct digital synthesis       DDS Drive for 136k    AD9832 from  SM6LKM - (Mk2)
QRSS  slowww CW       Slow CW    Work signals under the noise with your P.C.
Build a variable inductor       Variometer  250 - 400uH  built on standard fibreglass tubes. 
Stop QRM to medium wave with this low loss filter       500kHz     7 Element Chebyshev low pass filter design *NEW* April/07
CW / PSK31 / QRSS on 500k       500kHz     G0MRF 500kHz   3 mode beacon    *NEW* July/07
Small antennas work on 500k       500kHz     Small vertical antenna for the beacon    *NEW* Aug/07
Drake 2880 modifications
     Drake Mod's  A Series of modifications for the Drake 2880 S-Band converter
Receive converter 2.4G to 432 MHz    Satellites     An S-Band to 70cms converter for Phase 3D
satellites    Satellites      C Band transverter and dish feed for Phase 3D - Ooops!  No RX.....or AO-40
satellites    Satellites      AMSAT-UK and the SSETI Express project. U/S transponder.
satellites    Satellites      A demonstration mode U/V transponder  7/05
Poor performance receiving U Band?  - This is for you.    Satellites      High performance pre-amp for 70cms++  *NEW*  8/05
A rainy night in London......another satellite idea.    Satellites      Crazy satellite idea:  Medium Earth  Orbit at 7400km  10/05
2.4G source in 15 minutes    2.4 GHz Source    An all new source with a kit from AMSAT-UK. 
Where's my airline ticket?    DX-peditions.    Did you work us?    See the cards here

Where a project has been published, the original text is reproduced.
Up to-date developments / modifications to circuits are also included.

Recent additions:
Kit and component index.   - Pre-amp / transmitters / satellite converter and mod kits
Class D Transmitter - 300 Watts on 136kHz. Inc VXO / single PCB. / Transformer mod's by M0BMU
Redesigned version of the LF Pre-amp. (March 2003)
Horn Antenna for 2.4 GHz (via AO-40 page) 


      

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73

David Bowman   G0MRF                           Site last updated                       30th/Oct/2007