The EB104 board from MOTOROLA has gained high popularity among ham radio operators. It was designed by Helge O. Granberg of Motorola (sk) back in the 70ís.
HOG was probably the godfather of solid state power amplifiers.
His designs were built and copied all over the globe by hams and companies.
It offers a complete high power ,small size and modest cost of a broadband solid state amplifier.
On paper all looked good
After building more than a few modules I realized that I was not able to get the expected results from that board and design.
I decided to attempt a new board design and a new output transformer configuration.
The newly designed and built linear amp.
There are 4 MOS-FET transistors on the new designed silver plated
Double sided printed circuit board.
The transistors are SD2931-10 or SD2921-12 by ST micro. These are like the MRF-151 /MRF150 but with a higher gain and much better thermal structure!
Circuit uses parallel -push pull concept. Much like the very well-known EB104 board by MOTOROLA but with a new output transformer and better dc feed system.
There are 2 loops of feedback in the circuit to allow gain flatness and VERY reliable operation .
Four matched (QUAD) MOSFET's are used and each one has its own bias adjustment setting to allow precise current matching of the four FET's.
About 5-8 W in will give 600W out.
Working Voltage is 40- 50V D.C.
Current: Up to 30A on peaks.
All mounted on a heavy duty Machined HEAVY DUTY 11mm thick Aluminum base plate.
the pallet is pre-drilled, ready to by mounted to your choice of a heat sink.
The Pallet is 22cm x18 cm and is 11mm thick(!!).