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QCX+ 40m #9960 is go!


Shirley Dulcey KE1L
 

I ordered a QCX+ for 40 meters when the rig was first announced. I finally got around to building it just in time for QRP Afield yesterday -- the rig was literally aligned that morning and contacts during the contest period were its first appearance on the air.

There were two component problems with my kit. (No, Hans, this isn't a request for replacements.) One of the 10K resistors was missing, but I do a lot of digital stuff so I have plenty of those on hand in the parts bins. (As it happens I even had some 1% metal film resistors in that value so that's what I used. Not that it would have mattered; the substitute part went on the front panel board, and that one is a pulldown resistor for the rotary encoder.) The BNC connector was defective; the pin that goes to ground was broken off short. For now I substituted the connector from my 80m QCX+ kit, which is still unbuilt; when I build that one I'll extend the broken pin with a piece of cut-off component lead, but I had a deadline for completing this kit so I took the easy path.

(Speaking of that 80m kit, when I get around to building it I plan to use the alternate method of winding T1, with the three small windings on top done with some green wire left over from old Elecraft kits for visual contrast. That should make for a pretty toroid -- just have to make sure to get it done by Christmas!)

Only two parts of the build were at all difficult. Getting all the wires of T1 into the right holes is a bit of a bother, just as it was on my 20m QCX (a V2 board built shortly after that rig was introduced), but putting it on first made it easier. The other was the mounting arrangement for the front panel in the enclosure, and even Hans admits in the instructions that it's fiddly.

Once everything was together (minus the top cover) it was time for testing and alignment. As soon as I adjusted the contrast pot I got a reassuring display, and the rig aligned with no problems. (No need to take turns off T1 as I had to do on my 20m QCX.) A few hours later I had it out in the field (a portable operation on Four Tree Island in NH); my first contact was with WB2RPW, who was doing a portable operation in OH for the NJ QSO Party. I later made a couple of contacts with Norway in the Scandinavian Activity Contest -- I guess the rig works! (This was into an EFHW at about 10 feet. On 40 in the daytime. Not shabby. The seaside location probably helped, as did the fact that the stations at the other end were likely major contest stations with beam antennas.) I have not yet put it on the bench to test how much power is coming out, but clearly some is :)

Thank you, Hans, for another great building experience.


@CurtisM
 

Very FB

My new qcx plus is on 80m. Had 2 missing parts, first ever from qrplabs 470 pF and the bs170, and a large toroid broken in the PA kit.  I could not glue it back together,  so I have a pair of ft50-43 in its place. I will test the PA tomorrow to see what it does. The rig is amazing.

I looked at various winding methods for T1. I decided to go with traditional winding and use 3 different colors for the 5 turn winding. Maybe one of these colors came my k2 leftover or some prior kit. It was not hard to keep each winding the same direction,  and it was easy to see each winding.

Enjoy your radiations

Curt wb8yyy