EMRFD Message Archive 9408

Message Date From Subject
9408 2013-11-24 13:07:32 bkopski An Incidental NE602 Discovery


The NE602 Double-Balanced Mixer & Oscillator is a very popular, easy to use, generally good working 8 pin RF IC.  It has been used in countless receiver and other applications over several  decades by numerous home builders and some manufacturers too.  But – there may be a largely unnoticed 602 implementation characteristic that is an impediment to better performance in some applications.


A detailed description with photo data is presented in the new subfolder “INCIDENTAL NE602 DISCOVERY” under the main folder K3NHI-K5IRK-SSG.  This new subfolder is included in the main Simple Sweep Generator folder because the latter instrument is based in part on the NE602 and the findings are applicable to this instrument and potentially to most everything else with this IC in it.  Herein the SSG is its own application example.


Bob, K3NHI and John, K5IRK

((right now struggling to post the associated photos!!! - stand by))

9409 2013-11-24 15:55:10 bkopski Re: An Incidental NE602 Discovery

The associated photos have been posted in photos "Photos".

9410 2013-11-24 16:00:31 William Carver Re: An Incidental NE602 Discovery
As you are using it, with the NE602-as-VCO, there is probably BOTH AM
and PM noise generated by the power supply noise. I suspect supply noise
is amplified by the internal biasing and oscillator transistor. The AM
part could be reduced with a transformer between the differential
outputs, but you'd be stuck with the PM noise modulation.

The IC regulators bandgap references are noisy, and that noise can get
you. PA3AKE had regulator noise problems, and bandgap noise in the DDS
chips themselves, in his LO subsystem:


9411 2013-11-24 16:15:02 Russell Shaw Re: An Incidental NE602 Discovery
9412 2013-11-24 16:24:39 bkopski Re: An Incidental NE602 Discovery
Four associated data / photos have been posted in PHOTOS.



9413 2013-11-24 17:00:09 Russell Shaw Re: An Incidental NE602 Discovery