Re: Receiver module kit image rejection figure


Simon G0FCU
 

Simon might mean two 180-degree phases for the two signals into the double-balanced mixer. These are produced by windings of T1 in QCX, and by the trifilar transformer in the QRP Labs receiver module http://qrp-labs.com/receiver

Correct, I am using a trifilar transformer.

1) the Receiver module should provide around 40dB unwanted sideband rejection. There are no adjustments so the unwanted sideband is determined by the polyphase network topology and the component tolerances. 
2) QCX has a different method of phase shift using active all-pass op-amp networks; adjustments are available (to amplitude balance and phase shift) and tools are incorporate in the QCX to make the adjustments. After adjustment has been made, sideband suppression should be 50-60dB. 
 
Thank you for the confirmation. I'll order a Receiver module.

73 Simon
G0FCU.


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