Conclusion on the Filter Alignment

I have tried to use my other dummy load on the FT-817. It did indeed reduce the signal strength in the K1 quite a lot. This may sound a bit strange but it is not. You know, the DL-1 dummy load kit from Elecraft is an open dummy load, meaning that it is not in an enclosure, thus the RF signal is radiated from it. My other dummy load, on the other hand, is built into a piece of cooling metal and looks much more radiation closed than the DL-1 does.

I must admit that I am not completely satisfied with the alignment results on 40 and 30 meters. Furthermore, the displayed frequency on 40 meters is 5 kHz off while it is only 1 kHz off on the other bands.

This should complete the receiver tests and alignments. The next step is the assembly of part 2 of the RF board, namely the transmitter. Before I go on with that I think I will spend some more time playing with the filter board. Maybe I can achieve better results or at least I can get a clear picture of what is going on.

Author: Alexandru Csete

Embedded software engineer in the satcom industry during the day. Radio amateur and SDR hacker during the night.