13.56MHz ISM BAND AMPLIFIER USING 7NK30Z

Greetings Everyone,

Today we tested an ISM Band amplifier of 13.56 MHz with our standard R.C.T. ,Oscilloscope & Bird 500 Watts Dummy Load. It draws 10A at 33V D.C. That is 330W input and output of 200W. Upon calculating the efficiency more than 60%.

This time we have used a different MOSFET: STP 7NK30Z.  It can withstand up to 7A and maximum voltage of 300V. 7N stands for 7A rating and 30Z for 300V.  

BIRD's 8325 Tenuline Coaxial Attenuator

Greeting's,

First feast your eyes on the pictures below before I explain what this monster machine is.

 

This is a monstrous 500W, 50 Ohms, 30 dB Attenuator. We got this unit for testing our RF Amplifiers.

The following the specifications for the unit:

Impedance: 50 ohms nominal
Connectors
                  Input    : Bird “QC”, Female N normally supplied
                  Output : Bird “QC”, Female N normally supplied
Power Rating: 500W
Frequency Range: 500 MHz
Attenuation: 30 db ± ½ db, dc-500 MHz
Cooling Method: Dielectric and air convection currents

The Attenuator was tested with our amplifier and we are were exceptionally happy with the results.

The manual for the above unit can be downloaded for further reference from this link: Click Here. 

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.