Things I'm Learning: propagation and frequency on the Rockmite 20m

I'm not sure what to make of this yet, but I'm seeing different signal strengths received at the same receiving stations based on the output frequency of the Rockmite which only works on two different freuqencies: 14057.5 kHz and 14058.1 kHz.

Here's the data I collected this morning:

I wondered if this was simply variations in the atmostphere, but notice that in the case of reception by ND7K, there's a difference of 10 dB in the two transmitted frequencies with only a two minute difference between the measurement times. I saw even clearer results watching the waterfall display of the Utah SDR:

Notice the nice, well-defined line at 14057.5, and then a few seconds later, the fuzzy, weaker line at 14058.1:

first

second

I don't think it's an issu with the radio since sometimes the stronger recpetion was on 14057.5 and others it was on 14058.1.

I'm not sure what's causing the differences. I'm looking forward to finding out.

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