The SoftRock does not use H-Mode mixer it uses a QSD. A SoftRocks IP3 is around -20 dB due to the high gain of the op-amps they saturate long before the mixer does. The mixer I have not tested but I would expect somewhere in the +15 dB range.
At 10:59 PM 6/3/2007, you wrote: >Hello, >I am trying to understand the IIP3 concept a bit better. I get the >general idea that it is a non-linearity measure of mixer that takes >one tone, applies a non linearity and it will interfere with another >one of different frequency. According to this graph ><http://en.wikipedia.org/wiki/Image:Interceptpoint.png>http://en.wikipedia.org/wiki/Image:Interceptpoint.png >am I supposed to look for a large positive dBm to get good performance? > >Looking at the below figures: >AS8347: +11.5dBm >softrock40: above 30dBm >would this mean that the H mode FET switch mixers are far superior to >analog mixers in the IIP3 spec? > >Also, if I look at PA3AKE's comparison ><http://www.xs4all.nl/~martein/pa3ake/hmode/>http://www.xs4all.nl/~martein/pa3ake/hmode/ > >How am I supposed to interpret a table like: ><http://www.xs4all.nl/~martein/pa3ake/hmode/fsa3157.html>http://www.xs4all.nl/~martein/pa3ake/hmode/fsa3157.html > >Thanks, >Frank Cecil K5NWA www.softrockradio.org www.qrpradio.com www.hpsdr.com "Blessed are the cracked, for they shall let in the light."
