W4PA wrote:
>Lee Jones, inventor of the Jones filter, is WB4JTR and Ten-Tec's Chief
Technology Officer. Lee is a former Collins RF design engineer and has
had a significant impact on every piece of equipment we've built over
the past 20 years. His latest ham radio-related contribution for us was
designing the ultra-low phase noise synthesizer as used in the Orion's
main receiver.
Orion's exceptional close-in phase noise is truly one of its
major advantages. When looking at very close-spaced IMD and BDR
performance, phase noise often becomes the limiting factor in other
synthesized rigs. Rob Sherwood just updated his website which shows
both the Elecraft K2 and IC-7800 being phase noise limited at 2 kHz.
Their actual IMD performance is probably much better than the 80 dB
posted, but it becomes masked by close-in phase noise performance.
http://www.sherweng.com/Dayton_2004/Dynamic_Range_Data.pdf
Phase noise limitations at close spacings was also apparent in both
ARRL and RSGB Product Reviews of the IC-7800 done earlier this year.
Orion's phase noise performance is truly phenomenal and it is
very unlikely other rigs' phase noise can be improved much without a
complete redesign. Congratulations to Lee Jones on a truly significant
achievement! I only hope whatever he has done is patented.
73, Bill W4ZV
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