50 WATTS @ 12VOLTS HF AMPLIFIER USING 16NF06

Greetings to Every one,

We tested another one amplifier in our R&D Lab using 16NF06 mosfet.The results in 14MHz are amazing.We measured 50 watts output in 14MHz and more than 50 Watts in 7MHz using standard test Equipments HP 8920A RCT and GW-INSTEK 30MHz oscilloscope.It drawns 6Amp at 13.8VDC.The efficiency of this amplifier is 60%.  Below is the Photo and circuit details.

Note: T.S Means test select to adjust Minimum 10ma current in each MosFet.

1.) Input Transformer:

This is a step-down transformer. Primary is 4-Turns and secondary is 2-Turns wound on a TV balun core because maximum input power is 5 Watts only 26 SWG is sufficient. We have used 4-Turns primary with 26 SWG and 2-Turns secondary using 24 SWG.

2.) OUTPUT TRANSFORMER:

3.) Output Transformer:

This transformer was constructed using reference from Motorola book (R.F. Device Data -Vol. 2)

Primary consists of single turn copper tube of 4 mm diameter. Secondary consists of 2-Turns of Teflon coated wire.

Here we can see the copper tubes are shorted at one side. TV balun cores are slipped over the  copper tubes and secondary winding is completed last. The primary inductance of one turn copper tube should be 1uH. If the inductance is higher, this amplifier can works at lower frequencies. 

The above picture shows the PCB used to short the two copper tubes.

Here we can see the balun cores slipped over copper tubes.

Regards and Nice Home brewing,

R&D TEAM.