G0MRF  Projects


Amateur radio projects from 73kHz to 447THz

AO-73..... Live data from space @ www.warehouse.funcube.org.uk    Coming soon ESEO 23cm to 2m FM

       Overcome that front end attenautor and hear more DX on LF/MF   Life's too short for QRP. 300W on 630m     

Left: An old favourite revised with modern SMD coils.  Ready built  preamp for 136kHz and a new version for the 472kHz band.
Middle: A 300W Class D Amplifier for 630m.   Includes over current and hi ref power protection
Right: A 5W linear amplifier for 136 or 475kHz. (70k - 2MHz)

Kit and component pricelist    Kits and components Index.

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
CW / PSK beacon and antennas        500kHz experiments.
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)
As shown on the RSGB LF source book        300 Watts on 472kHz /630m with over current and SWR protection Kit available
As shown on the RSGB LF source book       A broadband 5Watt linear amplifier for 136 and 475kHz  Kit now available  09/2018

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
LF FET preamp        LF PreAmp and BPF. Make your black box work on LF and MF. New Version. Feb 14
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)
Build your own rocket       Coke Bottle Rocket Demo   A nice demo to turn a Coca-cola bottle into a rocket.
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. 

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      ESEO  - European Student Earth Orbiter  from ESA Education.  Launched Nov 2018
satellites    Satellites      AMSAT-UK and the SSETI Express project. U/S transponder
satellites    Satellites      A demonstration mode U/V transponder   7/05
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:
300W Amplifier for 472kHz / 630m - A 2016 design using 2 FETs in push pull. Ideal for WSPR beacons and CW QSOs
A 5Watt linear amplifier that works from 70kHz to 2MHz. Ideal for that low level from your Kenwood Icom or SDR Radio
The ESEO project. An inside view from an AMSAT perspective on this 49kg satellite from ESA Education


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David Bowman   G0MRF                           Site last updated                    19th/November/2018