K3 Testing Pt. III

A week on, and the K3 continues to impress.

RS232 Interface: Got the computer interface working, using a Keyspan USB Serial adapter. MacLogger DX has actual K3 support. Running Windows 2000 via Paralells on the MacBook Pro, allows me to finally try HamRadioDeluxe by HB9DRV - a very cool program which will take a bit of poking around on my part before coming to grips with all the features. HRD, however, does not support the full K3 command set, instead uses the K2 subset which is backwards compatible with the K3.

Firmware Updates: With the serial port tested and working I downloaded the Mac OS X version of the K3 Utility software. A couple of clicks later, my K3 has the latest firmware revisions installed (MCU: 1.66, DSP: 1.52). Kudos to the design team for such a smooth and elegant update process. Oh, the thought of all those times I had to disassemble the NRD-535's front panel to change EEPROMs... [shudder].

Headphones: I am not 100% satisfied with the audio quality of the Heil Proset headphones, and the frequency response of the Audio-Technica ATH-M3X stereo phones that I sometimes use is a little too broad for radio communications. Then I remembered that I got a pair of JRC ST-3 phones with my recent NRD-515 acquisition so gave them a try. Awesome... except that they are monophonic and will not work with the stereo AFX settings. But the gears are turning - can I rewire the ST-3 for stereo? Can I add a boom mic? Hmm...

RX Antenna: The Outbacker antenna is awful. Maybe that's because it's old and decrepit, maybe it's the installation, maybe it just never worked as well as I thought it did. In any case, it really sucks, no signals appear to be more than S5-S7 on the 40m band and even worse when tuning 80m, so I ran that Bell Imel eBay special to the RX Ant In and now see strong signals in excess of S9+10dB on all of the low bands which gives me a better idea of how the K3 will work when I finally get it hooked into a real antenna. Of course the noise level is also increased to S9 or so. This gives the NR and NB a good workout, and I'm pleased with the amount of noise reduction I'm able to dial in - not always enough to completely eliminate the noise but almost always sufficient to make a thoroughly unintelligible signal copyable. I also discovered that with antenna connected to RX ANT IN and second radio connected to RX ANT OUT, simultaneous reception on both radios is possible* making receiver comparisons easy.

Birdies: There are some nasty birdies on 80m band, especially down in the CW portion. They are heard with no antenna connected and vary in pitch when I adjust the filter controls, so I suspect they are being generated by either the DSP board or the MCU. I will go back into the rig and check that all screws are tight when I install the 100W PA.** Haven't noticed any loud birdies on other bands.

Miscellany: Decoded my first PSK31 signal. Figured out how to set and recall memory channels. Ditto CW messages. No further sign of PL1 ERR.

* Update 08-Feb-08: I've discovered that while reception on both radios is indeed simultaneous, when the RX ANT is selected the K3 will receive from the antenna connected to the RX ANT IN jack, but the second rig connected to RX ANT OUT will receive from the K3's main antenna (ANT 1 or ANT 2).

** Update 10-Feb-08: KPA3 is now installed, and although I didn't find anything loose that may have caused the birdies, after the PA was bolted in and the rig reassembled the birdies on 80m seem to have disappeared!