QRP Guys End Fed Half Wave Antenna – Part 3

Posted on by July 17, 2019
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I didn’t have time to test the antenna before our cabin trip, so I took some measurements on-site. The antenna was strung between the upper deck of the cabin and a nearby tree.

The wire I used was 63 feet long, I intended to cut it to length when the antenna was put up. What actually happened was I passed the end of the wire through a plastic dog bone insulator and wrapped it back on itself about a foot, and called it good. The SWR turned out to be so close to perfect, I didn’t make any adjustments.

Here is the performance data:

The performance of this antenna was outstanding. I made multiple contacts using no more than 5 watts. The rigs used were a QRP-Labs QCX, a QRP-Kits Weber Tri-bander, and a 4 states QRP Hilltopper. The contacts were from call areas 1,4,8 and 9. While listening to the band, I heard call signs from all 10 call areas in the continental US, Cuba, France and Germany.

uBitx – Part 4

Posted on by February 11, 2019
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Here is my completed uBitx. It worked perfectly the first time I applied power. Well, except I had the encoder wires backwards so the tuning was backwards, but I don’t count that.

The microphone, keyer and external speaker jacks are on the front panel. I plan to make custom knobs (red of course) on the lathe when I get time.

There is a custom made heat sink on the back. It connects to a custom made piece of thick aluminum on the inside of the case where the final transistors mount.

This view show power and RF connections. You can also see the inside portion of the heat sink.

Here is the inside view. ALL the components of the radio are attached to this half of the case to simplify things.

Here is a close up view of the wiring harness used to connect the Raduino to the main PCB. All clock outputs from the SI5351 are run in coax.