[Elecraft] Re: K3: birdie on 50.045?

[wayne burdick]

I'm glad to hear that there's only one little birdie of concern to the 
list. This is a major victory  :)  The K3 uses down-conversion to a low 
first I.F. (so we can offer narrowband crystal filters). It's nearly 
impossible to eliminate all birdies using this kind of conversion 
scheme.

Weak birdies generally arise from sum and difference products of VHF 
harmonics of the signal sources -- an unavoidable side-effect of a 
high-level switching mixer. But we made sure the birdies were minimized 
within ham bands by carefully choosing the I.F. (8.215 MHz), using 
integral low-pass filtering in the mixer switching path, and shielding 
the front panel module.

73,
Wayne
N6KR

---

http://www.elecraft.com