Tom says:
>I'm not talking about perfectly designed receivers, I was conveying
>how my FT-1000 actually measures.
That's damning with faint praise, Tom!!
>The worse thing in my FT1000 was the MOSFET in the noise
>blanker left hanging on the IF strip even when the noise blanker
>was off.
I've never yet found out why noise blankers always seem to screw up the
essentail parameters of a reciever, such as IMD. Also, designers seem to
have funny ides about MOSFETs - it's a dual gate MOSFET mixer that screws up
the spur performance of the FT102.
>After repairing that design error, the next worse problem was the
>RF amp with four push-pull parallel FET's.
Why do it that way? A push pull pair of 2N5109s with noiseless feedback
would probably be cheaper, and can give an intercept point more than good
enough for a +30dBm input intercept mixer. And to use +20dBm rx intercept
point, you need phase noise at -131dBc/Hz at 10kHz off (if you use 10/20kHz
spacing for IMD tests).
73
Peter G3RZP
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