Hello everybody, I have a friend's KFL3A-400 on my bench which shows a 20 dB passband attenuation with high ripple. The fault was originally detected by a 3 S units signal drop in the K3 compared to its other crystal filters. The filter was working perfectly until recently.
I disassembled and measured all crystals and they seem to be OK, with the exception of crystal no. 6 showing a higher ESR. But is this an issue? The input and output transfomers seem to be OK as well, although checked only for DC conductance and isolation. All solder joints have been checked. These are my measurement results: passband: http://www.dl1ekc.de/LinkedContent/DL3QQ_KFL3A-400.png crystals: http://www.dl1ekc.de/LinkedContent/DL3QQ_KFL3A-400_Quarze.pdf Any filter expert around here who can point me into the right direction? Any help is greatly appreciated. VY 73 Marcus ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
