I just finished doing some phase noise (and as a byproduct, frequency stability) measurements of a few ham radio HF transceivers and thought you might be interested in the results: http://www.febo.com/pages/hf_phase_noise/index.html
Many of you may not be familiar with the four rigs that I tested, but they were an interesting mix: 1. Yaesu FT-817 5 watt portable transceiver; almost current production (replaced by a slightly enhanced FT-817ND). It has an optional TCXO for its frequency reference. 2. Icom IC746 Pro 100 watt transceiver. This is a fairly typical mid-line rig that's in current production. It uses DSP fairly significantly but is not a Software Defined Radio. It also has an optional TCXO reference. 3. Flex-Radio SDR-1000 100 watt transceiver. The SDR-1000 is a true SDR and uses a PC with sound card as the signal processing engine. I tested the SDR-1000 using its standard 200 MHz XO (not TC) as well as several external reference sources, as there has been some uncertainty about the effect of multiplying a 10 MHz reference to 200 MHz on phase noise. 4. Finally, an old Kenwood TS-520S 100 watt rig with tubes in the final and a VFO (variable frequency oscillator) for you youngsters. No synthesizer at all, just a traditional superheterodyne. Some of the results may surprise you... John _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts