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Showing posts from January 28, 2020

Chinese connectors N-SMA , 23 January tropo

Last microwave meeting Heelweg,  I wanted to test my 23cm LNA  MMC SKY67151 https://vhfdesign.com/lna/lna-23cm-sky67151.html Like picture below but N connector version . The older type below has a bandpass 100MHz / -3db  exellent results low noise high gain no self oscillation no more 4G interference. The newer type has 20MHz bandpass a HAM friend wanted my old to use it for 23 ATV And i got a new in return Needed   N-SMA adapters since my tiny XVTR box at the dish uses SMA type relay The pre-amp / XVTR is direct at the dish. I got 2 "Chinese" N-SMA with it The measure crew at the noise figure stand told me right away you can throw this N-SMA in the bin... But please measure first and judge then.. It was found that the suspect adapter is not bad at all  adding about only 0.1dB to the noise figure. That is a normal insertion loss for a connector. A brand adapter Amphenol  offered 10€ used but gave no less noise then the suspect. Then another brand type w