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Feb, 2018 N9RIN reports the amplifier kit is no longer available due the PTF 10021 no longer in production. He is working on a substitute Jan, 2015 I have begun construction of the 30w 1296 Driver Amplifier from the kit sold by N9RIN. It consists of a single Infineon PTF 10021 LDMOS FET with 30w output at 28v, 2A. Quiescent load is 360ma and gain is 13dB so it drives with 1.5w. I will run it between 18-20w at 24v to provide drive to two 150w W6PQL amplifiers for combined output of 300w. The 2.5 by 3.75 inch pc board is shown, below. It will be mounted on a 5.375 by 5.00 by 1.375 inch aluminum heat sink with 1 inch high fins spaced five per inch. Additional cooling provided with a 4-inch fan. The board will be enclosed in a 5 by 4 by 3 -inch enclosure which will have a opening cut to permit the LDMOS transistor to be directly mounted to the heat sink. A 3-dB 100w chip attenuator will also be attached to the heat sink at the RF input to the amplifier. This will allow the transverter to drive at roughly 8w thru the 5.9-dB line loss to the location on the dish to provide 1w drive. The driver will be usable at half power to drive one of the 150w RF amplifier decks while the second 150w amplifier is under construction. Test Results Jan. 23 DC tests were first made with 12v supply; then 28v was used for final tests, below Vgq = 4.22v with Idq= 327 ma (no RF drive) Supply voltage is dropped thru two 5w 3.3-ohm resistors in parallel to keep Vds near 24v under full load. Drive Input Output* Vds Id 1.0w 0.5w 4.5w 25.82v 1.3a 1.5w 0.75w 6.0w 24.92v 1.87a 2.0w 1.0w 13.0w 24.80v 1.94a 2.5w 1.25w 20.0w --- --- 3.0w 1.5w 22.0w 24.10v 2.36a *After running the tests using a 50E element and Bird-43 power meter comparisons were made at 10w with a 10K element and the 50E element read 1.3 times higher. Neither element is calibrated so I cannot use either as an absolute power reference. The PTF 10021 was only mildly warm after all tests so heat sink is working fine. Photos of N9RIN 1296 PA:
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