[Elecraft] Six meter birdies

[Wes Stewart]

I read the digests, so I won't quote all of the helpful responses I've received on this topic but will add on here.

Let me restate, the K3 was operated without an antenna and just a 50-ohm termination on the antenna connector.  The only other piece of equipment operating in the shack was the Astron RS35A power supply.  I do not have a second receiver installed.  I have only the 2.8 KHz filter installed and all of these tests were with the default DSP BW.  Noise reduction and noise blanking were off.  The preamp was on and does make a difference in strength of the spurs, although many are heard without the preamp.

Per a suggestion from Tony, K2ZLS, I did a recalibration, which may have reduced the number of birdies, but certainly did not eliminate them.  I have checked all of the internal cable connections and they are fully engaged.

To be sure, most of these are very low level, but as on old EME op, they are Q5.

Someone wanted some frequencies listed.  Here are some, but by no means all of them, listed by mode in sets that seem to be related and slightly rounded:


F_lsb	F_usb	F_cw
50.0000	50.0000	50.0000
50.0270	50.0270	
50.0313	50.0342	50.0310
50.0400	50.0453	50.0395
50.0473	50.0476	50.0470
50.0750	50.0747	50.0755
50.0793	50.0773	
50.0953	50.0933	50.0950
50.0982	50.0988	50.0986
50.1108	50.1108	50.1116
50.1228	50.1228	50.1228
50.1363	50.1303	50.1356
50.1589	50.1588	50.1586

Years ago I built a high-performance HB receiver for 10-meters and i-f for transverters.  For evaluation I also built a test oscillator, like the XG-1 that used a 28.700 MHz crystal.  One of my first tests of the K3 was to use this oscillator to measure sensitivity.  By serendipity, the first birdie I discovered was at 28.700 +/- MHz.   Go figure.

Wes  N7WS