[Elecraft] K3 Rx IMD

[Geoffrey Mackenzie-Kennedy]

Ramiro,

Some very good information about Combiners is published on Jack Smith's 
website (Clifton Laboratories), also how to perform "IMD" tests.

The reason for using a lowpass filter between each generator and the 
combiner is to prevent the second harmonic of generator "A", for example, 
getting into generator "B", mixing with the fundamental of "B" to produce a 
third order product 2A - B. Similarly to keep the second harmonic of "B" out 
of "A". Any mixing of other harmonics can also result in "alien" third order 
products.

If you build a "pretty" version, I would suggest that each generator be 
built in its own metal box, with all DC supply leads filtered. What you do 
not want is the generators talking to each other :-)

Good luck with your project.

73,
Geoff
GM4ESD


Ramiro Aceves wrote on Thursday, November 25, 2010, at 7:52 AM:

> No problem. I cant resist what you propose. I am going to build Xtal
> oscillator. I have a 4 MHz cristal here. The the combiner.
> Keep tuned!
>
> Ramiro