144 MHz · 430 MHz · Technical

Rig Phase Noise Transmit Measurements

On the Rat’s internal MatterMost chat site we were talking about how the new Icom 705 portable rig would perform transmit-wise on 2/70 compared with a couple of recent rigs which have come in for some criticism in this respect.

Carl ICR got busy and put together some graphs based on published QST reviews. Below are the Phase Noise review measurements for the Icom 705 and the dedicated vhf/uhf  Icom 9700:

Carl combined these measurements into the graph below:

Very interesting I’m sure you’ll agree. With the caveat that 705 is “composite noise” and 9700 is “phase noise” in practice you would be concerned with noise more than 3kHz away from the carrier. So on 2m the 9700 at 100w is superior to the 10w 705. 70cm is different and accounting for the power difference could be considered more or less the same.

Carl produced similar comparison graphs for the much maligned (though very popular) Yaesu 991A.

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