#qcx QCX Kit Upgraded Revision 2 From a Swap Meet - Ready for SOTA #qcx

Dan Pflugrath

I purchased an unbuilt QCX-30 Revision 2 kit at a swap meet and ordered the capacitors to make it a QCX-20.  It went together without much difficulty and worked well both receive and transmit with an output power of 3 watts.  Per the discussions it put out 3.5 watts after I removed a turn from L3.  I then proceeded to blow one of the BS170's (shorted) which blew Q6 after upping the supply voltage to 16 volts hoping to run it directly off of a 4 cell LiPo battery.   I replaced all three BS170's, Q6 and the 74ACT00N which may have been damaged when the BS170 shorted.  Once I put it back together it is now outputting 5 watts with a supply voltage ranging from 12.5 volts to 13.5 volts.

I plan to use the QCX-20 for SOTA so I made my chassis out of polycarbonate sheet as small as possible, 4.5 X 5 X 1.5 inches.  Included inside are an 850 mAh 4 cell LiPo battery and a regulator to keep the supply voltage to 13.5 volts or less.  

In the picture all that is needed is my End Fed Half Wave antenna.  My first contact with the completed assembly was from the Seattle area to Alaska with a 589 report.  
73 Dan KA7GPP