Microwave Amateur Radio Station, Waterbeach. 8km North Of Cambridge JO02cg

To Contact me:

Skype johng4bao

E-mail john at g4bao dot com


About me 

My Equipment


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Downloads and Bodger's Guides 

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Welcome to G4BAO's Amateur Radio Website

Updated 29/06/2022

Driver kits - update. Now available again.

Last chance for 23cm boards

The LDMOS device PD85004 as used in my 70 and 23cm 3W driver board kits is now obsolete and no stock has been available anywhere for around 2 years. I have around 15 devices remaining so order the 23cm boards while you can.
I have a working design for 70cm using an alternative device in the same package, with just a few minor changes to the design.
The new device is just not capable of operating at 23cm with any significant gain or output power, and  have been unable to find a suitable replacement, so that design is now officially withdrawn and unavailable.
I will put the 23cm kit info on Github with my other "retired" designs in due course.  The new device has slightly lower gain than the old device at 70cm, requiring around +14dBm (without the 3dB input attenuator) to produce 3 Watts Psat.

G4BAO 45W 23cm PA is now public domain

I no longer supply these kits so the designs are made available at


Copy and paset the above URL in to your browser

under an MIT licence. I've included a copy of the original article, Eagle board and schematic files, plus Gerber files for the PCB. Enjoy

 My RSGB Convention 2015 and 2016 presentations, "A deeper understanding of meteor scatter" and "Moving up to 23cms" are on the RSGB Youtube channel 

 The UKuG Backscatter book is  now downloadable from



GHz Bands Operation from G4BAO

I'm QRV on 10GHz EME and 1.3,3.4 and 24GHz terrestrial .

On EME I use a Homebrew 25W PA and a 1.2m dish with a Chaparal feed  


NEW!!! Experimental G4BAO Club log search (160m-13cm only) 

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Waterbeach in the Winter Floods


                The river Cam at  Waterbeach


             Sunset over Waterbeach




Oliver is not a kitten anymore!







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