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[Sheldon Hands]

> The 140W amp is the Motorola AN762 amplifier kit from Communication 
> Concepts. I've built one of these - simple and easy to build. Good results 
> up to 10metres. I don't recognise the 300W amp tho'.
>




The AN762 is nice little amp board. It will take MRF453/454/ 421 and also 
SD1405. I have built a number of theses boards with both SD1405 and MRF454 
transistors  and currently use a 454 version driven from Pen via a push pull 
pair of 2SC2166.



 I do not recommend the use of  the MRF453 version, I found them very easy 
to overdrive  and burn out!! especially when attempting 100w on 10mtrs.

Board control is very easy and just needs a track cut on the +12 to the bias 
reg to seperate it from the main PA +VE. If you use the AN762 PDF and copy 
the PCB layout to a tranparency its simple to scratch out some track and add 
a couple of pin headers. 13.8V is then a a permeant connection and 12V 
transmit supplies the Bias reg.


Shel CT1IZU 


 1267461531.0