[Elecraft] KX3 schematics

[Giancarlo Moda]

Dear Wayne,

thank you for posting the note about the availability of KX3 schematic diagrams. I was waiting for these since a long time, I was very courious to see the mixers selected, there is always something to learn.


I would like to compliment the design team for the KX3 RX mixer. I thought they were going to use a "classic" QSD using the FST3253, like in the Flex-1500 or the Softrock, or similar to the one used in the TX mixer. 

I like the RX mixer using the FST3257/74CBT3257, this one should have a lower noise, going up in frequency, than a similar one using the FST3253.  This latter device has an internal clock decoding and the balanced LO waveform cannot directly control the switches gates, i.e. a 50-50 clock may result in a 49-51 signal switching, or vice a versa, while with the FST3257 the gates are directly controlled by the clock waveform.

I garantee you I will not try to modify this mixer .. although I could have a different solution ... hi


Congratulations again for a nice product

Best 73

Gian
I7SWX

Message: 38
Date: Tue, 5 Mar 2013 17:16:01 -0800
From: Wayne Burdick <n6kr at elecraft.com>
To: KX3 at yahoogroups.com
Cc: Elecraft Reflector <elecraft at mailman.qth.net>
Subject: [Elecraft] KX3 schematics
Message-ID: <F95BF4D9-3172-4054-961E-41E9B4887E4A at elecraft.com>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes

The full KX3 schematic package is now available on our Manual Download  
page.

73,
Wayne
N6KR