[Elecraft] K3 birdies - question?

[d.cutter at ntlworld.com]

So, could we use the good old methods of wrapping the coax around a suitable toroid.  That would mean a longer cable at which point I would invest in a better quality cable if I were doing it and I'm tempted to do so to get the best chance of cracking the main issues we are addressing.

David
G3UNA

---- Geoffrey Mackenzie-Kennedy <gm4esd at btinternet.com> wrote: 
> David,
> 
> Double shielded coax would certainly reduce leakage from the coax, and is a 
> good investment in my opinion. However its use might not have too much 
> impact on the receiver's birdie problem, because many of the "rogue" signals 
> involved are probably flowing on the outside of the coax's braid, certainly 
> if the coax emerges from some enclosure through a hole.
> 
> The usual cause of a receiver birdie is that some response of the receiver 
> is "hearing" some oscillator or a harmonic, or some mixing product of two or 
> more oscillators, contained within the receiver. In a down conversion HF 
> receiver, the great majority of the receiver's responses, therefore the 
> "rogue signals", that cause birdie problems are at HF and up to low/ mid 
> VHF, which means that choking off coax runs within a receiver becomes 
> cumbersome.
> 
> 73,
> 
> Geoff
> GM4ESD
> 
> David Cutter wrote on Wednesday, March 04, 2009, at 10:32 AM:
> 
> >I also wonder if it would be worthwhile buying higher spec coax.  Don't 
> >know what is used in the K3, but for the lengths involved it would be worth 
> >the investment to get short cables made in say LMR100 or RG142 etc if it's 
> >not already
> >
> > David
> > G3UNA
> 
> 
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