Description

SEE LINK BELOW FOR DEMONSTRATION This QRP amplifier will get you to between 75-120 watts depending on the band and input drive power. Definitely a large increase and the difference is easily heard using WebSDR. This package I created contains the amplifier and it’s necessary Low Pass Filter all in the same housing. Easy power connection using Anderson PowerPoles and PTT signal using any RCA cable. A high quality output COAX was special ordered from ABR Industries… it is equivalent to RG-8x. Here is the story… These amps were sold by Radioddity for around 156 dollars. The low pass filter sections was also sold for about 93 dollars. My cost was 250, for an amp which likes to POP the final transistors if SWR or HEAT is too much. It had blown on me after using it during long 20m SSB and CW QSOs. Solution: I desoldered the blown transistors and soldered in IC sockets to accept the legs of new replacement transistors. iRF 530s. This works good. You cut the legs shorter on the new mosfetts and spread a little Thermal past and reinstall new low cost Finals ( IF THE HEAT WAS TOO MUCH). I suggest putting another little fan Not Included forcing air right onto the finals. Mouser sells high quality ones for a few bucks a piece.. I will include all that I have left… 4. If it gets too hot and blows again, it usually will be just one of them. The ABR COAX is about 25 bucks just by itself…. To use amp, flip the rocker switch sideways, OFF is straight out. The LOW pass filter has its own button and it must be turned on for Any signal to get through, whether the amp is ON or OFF. High SWR will show if the LPF is not turned on. You get used to making this baby PUMP your signal up…. Plug in, flip case open press The Band of choice button, then flip the rocker switch to let the Signal AMPLIFY. It works good… 40 meters is about 90 watts and 20 meters shows about 80-110. Accuracy of power meters are the unknown, and how well tuned the antenna is. DO NOT USE Internal radio Antenna tuner when using this amp. If your antenna is not too resonant, use an external tuner after the AMP AND SWR meter and In front of the Antenna. Drive signal with these good Mouser Mosfets needs to be about 2 watts. One main fuse will be included… This amp will get you closer to 100watts with your QRP radio. Enjoy the product and contact me if you have any questions. 73 not 72 Hi Hi HERE IS A VIDEO SHOWING THIS AMP IN USE https://youtu.be/DX5zjmnc240?si=HaFiOAu2qp4pnLUx