008: 10368MHz Low noise amplifier for EME


The motive to make this is that I wanted to make more low noise 10GHz preamps based on LNA (WDG-004) of G3WDG. In those days, HEMT that improved its performance further was announced one after another in Japan. As the FHX13LG of Fujitsu was especially famous as the best device for 12GHz, I decided to use it in the new 10GHz LNA. I chose the Teflon glass substrate of 0.79mm thickness for the PCB. The impedance conversion pattern of the signal line is a copy of WDG. However, the source pattern applied the through hole unlike original WDG-004. Moreover, all 1/4 wavelength chalk stubs of the DC line are modified to printed pattern, too. I aimed at making to a low loss further by it. This PCB was manufactured by JA0QDE/Mr. Yoneyama. Because he was a professional, the make was beautiful indeed. The completed preamp showed a performance that was the same as the original of NF0.85-0.95dB and Gain11.5dB. However, NF0.7dB of the target was not able to be cleared to my regret. I think the source pattern and the chalk stub to have been optimized almost. Still, it did not come to cancel the radiation loss from the pattern. In the VE3ONT test in 1995, I succeeded to hear the X-band moon echo for the first time in Japan using this LNA. I visited G3WDG/Charlie in England twice around it. This preamplifier was measured at the test bench in his home shack then. Making was in 1994.



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