Re: KPA-100 pop from TX to RX

Posted by DaveVK on
URL: http://elecraft.85.s1.nabble.com/KPA-100-pop-from-TX-to-RX-tp7576200p7576243.html

Don,

I have fixed the mechanical buzz from the SSB tx on the KPA-100.  The fault was mine.  Across the RF Aux input between the PCB and the heatsink there seems to be a blue resistor with the colours Brn-Blk-Blk-Org-Brn with one leg that was touching the heat sink.  The legs are long and so I just pushed it away with a screwdriver.  I don't know what that part is doing there, or why it is installed like a hack did the job but the memory of it is lost in history.

I cannot find the part listed in the KPA instruction manual or any of the upgrade kits. So maybe it doesn't belong there??!!  But anyway, that problem is fixed and the next time I'm in a position to remove the heatsink I'll install that part properly.

I seem to have the upgrade kit installed and the blue cores are in the KPA-100.

Now the popping is unsolved.  It seems to be connected to the DSP.   The popping is most prominent on bands below 20m.  When the DSP is bypassed the popping disappears.  I am still hunting this one down.