Saturday, 22 May 2010

K1 build. Up to RF board Part I

Just finished the build of the K1 up to the end of the RF Board Part 1.

Short video of the finished article.
video

The current draw with the back light is 64mA.

RX side all done and aligned. I used three signal sources, an FT817, a USB Si570 and a Colpitts Crystal oscillator using 2N3904 and 7.040MHz and 14.060 MHz so should be pretty true but the frequency can be amended through the menus. But once amended for 40m automatically the signal frequency for 20m was correct.

I have done the alignment with a side tone at 600Hz feeding the signals into a PC and used adjusted with an audio scope, built with stereo audio and the side tone is working fine and both hand and paddle key work fine. I have left keyer at 16wpm for now.

I might have to adjust the menu for S meter readings that suit later as I have left the level at L50 which is the default. I was listening to a cw contest and some of the local stations were definitely S9 and appeared so but the weaker ones did not seem to move the S meter. AGC is audio derived so an s9+40 signal causes a 'blip' and the AGC attacks hard the AGC decays pretty slowly. Turn it off and no S meter.

About to get the TX side started.

No comments: